1
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van Kesteren S, Diethelm P, Jung SH, Isa L. DNA-Based Replication of Programmable Colloidal Assemblies. Small 2024:e2400180. [PMID: 38693098 DOI: 10.1002/smll.202400180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/05/2024] [Indexed: 05/03/2024]
Abstract
Nature uses replication to amplify the information necessary for the intricate structures vital for life. Despite some successes with pure nucleotide structures, constructing synthetic microscale systems capable of replication remains largely out of reach. Here, a functioning strategy is shown for the replication of microscale particle assemblies using DNA-coated colloids. By positioning DNA-functionalized colloids using capillary forces and embedding them into a polymer layer, programmable sequences of patchy particles are created that act as a primer and offer precise binding of complementary particles from suspension. The strings of complementary colloids are cross-linked, released from the primer, and purified via flow cytometric sorting to achieve a purity of up to 81% of the replicated sequences. The replication of strings of up to five colloids and non-linear shapes is demonstrated with particles of different sizes and materials. Furthermore, a pathway for exponential self-replication is outlined, including preliminary data that shows the transfer of patches and binding of a second-generation of assemblies from suspension.
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Affiliation(s)
- Steven van Kesteren
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
| | - Pascal Diethelm
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
| | - Se-Hyeong Jung
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
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2
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Scherrer S, Ramakrishna SN, Niggel V, Spencer ND, Isa L. Measuring Rolling Friction at the Nanoscale. Langmuir 2024; 40:6750-6760. [PMID: 38497776 PMCID: PMC10993404 DOI: 10.1021/acs.langmuir.3c03499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/24/2024] [Accepted: 02/27/2024] [Indexed: 03/19/2024]
Abstract
Colloidal probe microscopy, a technique whereby a microparticle is affixed at the end of an atomic force microscopy (AFM) cantilever, plays a pivotal role in enabling the measurement of friction at the nanoscale and is of high relevance for applications and fundamental studies alike. However, in conventional experiments, the probe particle is immobilized onto the cantilever, thereby restricting its relative motion against a countersurface to pure sliding. Nonetheless, under many conditions of interest, such as during the processing of particle-based materials, particles are free to roll and slide past each other, calling for the development of techniques capable of measuring rolling friction alongside sliding friction. Here, we present a new methodology to measure lateral forces during rolling contacts based on the adaptation of colloidal probe microscopy. Using two-photon polymerization direct laser writing, we microfabricate holders that can capture microparticles, but allow for their free rotation. Once attached to an AFM cantilever, upon lateral scanning, the holders enable both sliding and rolling contacts between the captured particles and the substrate, depending on the interactions, while simultaneously giving access to normal and lateral force signals. Crucially, by producing particles with optically heterogeneous surfaces, we can accurately detect the presence of rotation during scanning. After introducing the workflow for the fabrication and use of the probes, we provide details on their calibration, investigate the effect of the materials used to fabricate them, and report data on rolling friction as a function of the surface roughness of the probe particles. We firmly believe that our methodology opens up new avenues for the characterization of rolling contacts at the nanoscale, aimed, for instance, at engineering particle surface properties and characterizing functional coatings in terms of their rolling friction.
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Affiliation(s)
- Simon Scherrer
- Department of Materials, ETH
Zürich, Zürich 8093, Switzerland
| | | | - Vincent Niggel
- Department of Materials, ETH
Zürich, Zürich 8093, Switzerland
| | | | - Lucio Isa
- Department of Materials, ETH
Zürich, Zürich 8093, Switzerland
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3
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van Kesteren S, Diethelm P, Isa L. Fluorescence-activated cell sorting (FACS) for purifying colloidal clusters. Soft Matter 2024; 20:2881-2886. [PMID: 38477048 DOI: 10.1039/d4sm00122b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Colloidal particles are considered to be essential building blocks for creating innovative self-assembled and active materials, for which complexity beyond that of compositionally uniform particles is key. However, synthesizing complex, multi-material colloids remains a challenge, often resulting in heterogeneous populations that require post-synthesis purification. Leveraging advances brought forward in the purification of biological samples, here we apply fluorescence-activated cell sorting (FACS) to sort colloidal clusters synthesized through capillary assembly. Our results demonstrate the effectiveness of FACS in sorting clusters based on size, shape, and composition. Notably, we achieve a sorting purity of up to 97% for clusters composed of up to 9 particles, albeit observing a decline in purity with increasing cluster size. Additionally, dimers of different colloids can be purified to over 97%, while linear and triangular trimers can be separated with up to 88% purity. This work underscores the potential of FACS as a promising and little-used tool in colloidal science to support the development of increasingly more intricate particle-based building blocks.
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Affiliation(s)
- Steven van Kesteren
- Laboratory for Soft Materials and Interfaces, ETH Zurich, Vladmir-Prelog-Weg 1-5, Zurich, 8093, Switzerland.
| | - Pascal Diethelm
- Laboratory for Soft Materials and Interfaces, ETH Zurich, Vladmir-Prelog-Weg 1-5, Zurich, 8093, Switzerland.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, ETH Zurich, Vladmir-Prelog-Weg 1-5, Zurich, 8093, Switzerland.
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4
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Bailey MR, Barriuso Gutiérrez CM, Martín-Roca J, Niggel V, Carrasco-Fadanelli V, Buttinoni I, Pagonabarraga I, Isa L, Valeriani C. Minimal numerical ingredients describe chemical microswimmers' 3-D motion. Nanoscale 2024; 16:2444-2451. [PMID: 38214073 DOI: 10.1039/d3nr03695b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
The underlying mechanisms and physics of catalytic Janus microswimmers is highly complex, requiring details of the associated phoretic fields and the physiochemical properties of catalyst, particle, boundaries, and the fuel used. Therefore, developing a minimal (and more general) model capable of capturing the overall dynamics of these autonomous particles is highly desirable. In the presented work, we demonstrate that a coarse-grained dissipative particle-hydrodynamics model is capable of describing the behaviour of various chemical microswimmer systems. Specifically, we show how a competing balance between hydrodynamic interactions experienced by a squirmer in the presence of a substrate, gravity, and mass and shape asymmetries can reproduce a range of dynamics seen in different experimental systems. We hope that our general model will inspire further synthetic work where various modes of swimmer motion can be encoded via shape and mass during fabrication, helping to realise the still outstanding goal of microswimmers capable of complex 3-D behaviour.
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Affiliation(s)
- Maximilian R Bailey
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich, Switzerland
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Madrid, Spain.
| | - C Miguel Barriuso Gutiérrez
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Madrid, Spain.
| | - José Martín-Roca
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Madrid, Spain.
- Departamento de Química Física, Facultad de Química, Universidad Complutense de Madrid, Madrid, Spain
| | - Vincent Niggel
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich, Switzerland
| | - Virginia Carrasco-Fadanelli
- Department of Physics, Institute of Experimental Colloidal Physics, Heinrich-Heine University, Düsseldorf, Germany
| | - Ivo Buttinoni
- Department of Physics, Institute of Experimental Colloidal Physics, Heinrich-Heine University, Düsseldorf, Germany
| | - Ignacio Pagonabarraga
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona, Spain
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, Barcelona, Spain
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich, Switzerland
| | - Chantal Valeriani
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Madrid, Spain.
- GISC - Grupo Interdiplinar de Sistemas Complejos, Madrid, Spain
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5
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van Baalen C, Uspal WE, Popescu MN, Isa L. Transition from scattering to orbiting upon increasing the fuel concentration for an active Janus colloid moving at an obstacle-decorated interface. Soft Matter 2023; 19:8790-8801. [PMID: 37946586 PMCID: PMC10663988 DOI: 10.1039/d3sm01079a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/26/2023] [Indexed: 11/12/2023]
Abstract
Efficient exploration of space is a paramount motive for active colloids in practical applications. Yet, introducing activity may lead to surface-bound states, hindering efficient space exploration. Here, we show that the interplay between self-motility and fuel-dependent affinity for surfaces affects how efficiently catalytically-active Janus microswimmers explore both liquid-solid and liquid-fluid interfaces decorated with arrays of similarly-sized obstacles. In a regime of constant velocity vs. fuel concentration, we find that microswimmer-obstacle interactions strongly depend on fuel concentration, leading to a counter-intuitive decrease in space exploration efficiency with increased available fuel for all interfaces. Using experiments and theoretical predictions, we attribute this phenomenon to a largely overlooked change in the surface properties of the microswimmers' catalytic cap upon H2O2 exposure. Our findings have implications in the interpretation of experimental studies of catalytically active colloids, as well as in providing new handles to control their dynamics in complex environments.
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Affiliation(s)
- Carolina van Baalen
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - William E Uspal
- Department of Mechanical Engineering, University of Hawai'i at Mānoa, 2540 Dole St., Holmes Hall 302, Honolulu, HI 96822, USA.
| | - Mihail N Popescu
- Department of Atomic, Molecular, and Nuclear Physics, University of Seville, 41080 Seville, Spain.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
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6
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Boggon C, Mairpady Shambat S, Zinkernagel AS, Secchi E, Isa L. Single-cell patterning and characterisation of antibiotic persistent bacteria using bio-sCAPA. Lab Chip 2023; 23:5018-5028. [PMID: 37909096 PMCID: PMC10661667 DOI: 10.1039/d3lc00611e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/13/2023] [Indexed: 11/02/2023]
Abstract
In microbiology, accessing single-cell information within large populations is pivotal. Here we introduce bio-sCAPA, a technique for patterning bacterial cells in defined geometric arrangements and monitoring their growth in various nutrient environments. We demonstrate bio-sCAPA with a study of subpopulations of antibiotic-tolerant bacteria, known as persister cells, which can survive exposure to high doses of antibiotics despite lacking any genetic resistance to the drug. Persister cells are associated with chronic and relapsing infections, yet are difficult to study due in part to a lack of scalable, single-cell characterisation methods. As >105 cells can be patterned on each template, and multiple templates can be patterned in parallel, bio-sCAPA allows for very rare population phenotypes to be monitored with single-cell precision across various environmental conditions. Using bio-sCAPA, we analysed the phenotypic characteristics of single Staphylococcus aureus cells tolerant to flucloxacillin and rifampicin killing. We find that antibiotic-tolerant S. aureus cells do not display significant heterogeneity in growth rate and are instead characterised by prolonged lag-time phenotypes alone.
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Affiliation(s)
- Cameron Boggon
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Switzerland.
| | - Srikanth Mairpady Shambat
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zürich, University of Zurich, Switzerland
| | - Annelies S Zinkernagel
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zürich, University of Zurich, Switzerland
| | - Eleonora Secchi
- Institute of Environmental Engineering, Department of Civil, Environmental, and Geomatic Engineering, ETH Zürich, Switzerland.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Switzerland.
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7
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Bordon G, Ramakrishna SN, Edalat SG, Eugster R, Arcifa A, Vermathen M, Aleandri S, Bertoncelj MF, Furrer J, Vermathen P, Isa L, Crockett R, Distler O, Luciani P. Liposomal aggregates sustain the release of rapamycin and protect cartilage from friction. J Colloid Interface Sci 2023; 650:1659-1670. [PMID: 37494862 DOI: 10.1016/j.jcis.2023.07.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
Liposomes show promise as biolubricants for damaged cartilage, but their small size results in low joint and cartilage retention. We developed a zinc ion-based liposomal drug delivery system for local osteoarthritis therapy, focusing on sustained release and tribological protection from phospholipid lubrication properties. Our strategy involved inducing aggregation of negatively charged liposomes with zinc ions to extend rapamycin (RAPA) release and improve cartilage lubrication. Liposomal aggregation occurred within 10 min and was irreversible, facilitating excess cation removal. The aggregates extended RAPA release beyond free liposomes and displayed irregular morphology influenced by RAPA. At nearly 100 µm, the aggregates were large enough to exceed the previously reported size threshold for increased joint retention. Tribological assessment on silicon surfaces and ex vivo porcine cartilage revealed the system's excellent protective ability against friction at both nano- and macro-scales. Moreover, RAPA was shown to attenuate the fibrotic response in human OA synovial fibroblasts. Our findings suggest the zinc ion-based liposomal drug delivery system has potential to enhance OA therapy through extended release and cartilage tribological protection, while also illustrating the impact of a hydrophobic drug like RAPA on liposome aggregation and morphology.
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Affiliation(s)
- Gregor Bordon
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Shivaprakash N Ramakrishna
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir- Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Sam G Edalat
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952 Schlieren, Switzerland
| | - Remo Eugster
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Andrea Arcifa
- Laboratory for Surface Science and Coating Technologies, EMPA, Uberlandstrasse 129, 8600 Dubendorf, Switzerland
| | - Martina Vermathen
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Simone Aleandri
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | | | - Julien Furrer
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Peter Vermathen
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, University & Inselspital Bern, sitem-insel AG, Freiburgstrasse 3, 3010 Bern, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir- Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Rowena Crockett
- Laboratory for Surface Science and Coating Technologies, EMPA, Uberlandstrasse 129, 8600 Dubendorf, Switzerland
| | - Oliver Distler
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952 Schlieren, Switzerland
| | - Paola Luciani
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland.
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8
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Meijs ZC, Yun HS, Fandre P, Park G, Yoon DK, Isa L. Pixelated Physical Unclonable Functions through Capillarity-Assisted Particle Assembly. ACS Appl Mater Interfaces 2023; 15. [PMID: 37910785 PMCID: PMC10658447 DOI: 10.1021/acsami.3c09386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/15/2023] [Accepted: 10/17/2023] [Indexed: 11/03/2023]
Abstract
Recent years have shown the need for trustworthy, unclonable, and durable tokens as proof of authenticity for a large variety of products to combat the economic cost of counterfeits. An excellent solution is physical unclonable functions (PUFs), which are intrinsically random objects that cannot be recreated, even if illegitimate manufacturers have access to the same methods. We propose a robust and simple way to make pixelated PUFs through the deposition of a random mixture of fluorescent colloids in a predetermined lattice using capillarity-assisted particle assembly. As the encoding capacity scales exponentially with the number of deposited particles, we can easily achieve encoding capacities above 10700 for sub millimeter scale samples, where the pixelated nature of the PUFs allows for easy and trustworthy readout. Our method allows for the PUFs to be transferred to, and embedded in, a range of transparent materials to protect them from environmental challenges, leading to improved stability and robustness and allowing their implementation for a large number of different applications.
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Affiliation(s)
- Zazo Cazimir Meijs
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Hee Seong Yun
- Department
of Chemistry, Korea Advanced Institute of
Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Pascal Fandre
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Geonhyeong Park
- Department
of Chemistry, Korea Advanced Institute of
Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Dong Ki Yoon
- Department
of Chemistry, Korea Advanced Institute of
Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Lucio Isa
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
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9
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Vialetto J, Camerin F, Ramakrishna SN, Zaccarelli E, Isa L. Exploring the 3D Conformation of Hard-Core Soft-Shell Particles Adsorbed at a Fluid Interface. Adv Sci (Weinh) 2023; 10:e2303404. [PMID: 37541434 PMCID: PMC10558683 DOI: 10.1002/advs.202303404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/11/2023] [Indexed: 08/06/2023]
Abstract
The encapsulation of a rigid core within a soft polymeric shell allows obtaining composite colloidal particles that retain functional properties, e.g., optical or mechanical. At the same time, it favors their adsorption at fluid interfaces with a tunable interaction potential to realize tailored two-dimensional (2D) materials. Although they have already been employed for 2D assembly, the conformation of single particles, which is essential to define the monolayer properties, has been largely inferred via indirect or ex situ techniques. Here, by means of in situ atomic force microscopy experiments, the authors uncover the interfacial morphology of hard-core soft-shell microgels, integrating the data with numerical simulations to elucidate the role of the core properties, of the shell thicknesses, and that of the grafting density. They identify that the hard core can influence the conformation of the polymer shells. In particular, for the case of small shell thickness, low grafting density, or poor core affinity for water, the core protrudes more into the organic phase, and the authors observe a decrease in-plane stretching of the network at the interface. By rationalizing their general wetting behavior, such composite particles can be designed to exhibit specific inter-particle interactions of importance both for the stabilization of interfaces and for the fabrication of 2D materials with tailored functional properties.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory for Soft Materials and InterfacesDepartment of MaterialsETH ZürichVladimir‐Prelog‐Weg 5Zürich8093Switzerland
- Present address:
Department of Chemistry & CSGIUniversity of Florence, via della Lastruccia 3Sesto FiorentinoFirenzeI‐50019Italy
| | - Fabrizio Camerin
- CNR Institute for Complex SystemsUos SapienzaP.le A. Moro 2Roma00185Italy
- Department of PhysicsSapienza University of RomeP.le A. Moro 2Roma00185Italy
- Soft Condensed Matter & BiophysicsDebye Institute for Nanomaterials ScienceUtrecht UniversityPrincetonplein 1CC Utrecht3584The Netherlands
| | - Shivaprakash N. Ramakrishna
- Laboratory for Soft Materials and InterfacesDepartment of MaterialsETH ZürichVladimir‐Prelog‐Weg 5Zürich8093Switzerland
| | - Emanuela Zaccarelli
- CNR Institute for Complex SystemsUos SapienzaP.le A. Moro 2Roma00185Italy
- Department of PhysicsSapienza University of RomeP.le A. Moro 2Roma00185Italy
| | - Lucio Isa
- Laboratory for Soft Materials and InterfacesDepartment of MaterialsETH ZürichVladimir‐Prelog‐Weg 5Zürich8093Switzerland
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10
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van Baalen C, Vialetto J, Isa L. Tuning Electrostatic Interactions of Colloidal Particles at Oil-Water Interfaces with Organic Salts. Phys Rev Lett 2023; 131:128202. [PMID: 37802948 DOI: 10.1103/physrevlett.131.128202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/23/2023] [Indexed: 10/08/2023]
Abstract
Monolayers of colloidal particles at oil-water interfaces readily crystallize owing to electrostatic repulsion, which is often mediated through the oil. However, little attempts exist to control it using oil-soluble electrolytes. We probe the interactions among charged hydrophobic microspheres confined at a water-hexadecane interface and show that repulsion can be continuously tuned over orders of magnitude upon introducing nanomolar amounts of an organic salt into the oil. Our results are compatible with an associative discharging mechanism of surface groups at the particle-oil interface, similar to the charge regulation observed for charged colloids in nonpolar solvents.
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Affiliation(s)
- Carolina van Baalen
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Jacopo Vialetto
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
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11
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Müller FJ, Isa L, Vermant J. Toughening colloidal gels using rough building blocks. Nat Commun 2023; 14:5309. [PMID: 37652918 PMCID: PMC10471594 DOI: 10.1038/s41467-023-41098-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/02/2023] Open
Abstract
Colloidal gels, commonly used as mesoporous intermediates or functional materials, suffer from brittleness, often showing small yield strains on the order of 1% or less for gelled colloidal suspensions. The short-range adhesive forces in most such gels are central forces-combined with the smooth morphology of particles, the resistance to yielding and shear-induced restructuring is limited. In this study, we propose an innovative approach to improve colloidal gels by introducing surface roughness to the particles to change the yield strain, giving rise to non-central interactions. To elucidate the effects of particle roughness on gel properties, we prepared thermoreversible gels made from rough or smooth silica particles using a reliable click-like-chemistry-based surface grafting technique. Rheological and optical characterization revealed that rough particle gels exhibit enhanced toughness and self-healing properties. These remarkable properties can be utilized in various applications, such as xerogel fabrication and high-fidelity extrusion 3D-printing, as we demonstrate in this study.
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Affiliation(s)
| | - Lucio Isa
- Department of Materials, ETH Zurich, Switzerland
| | - Jan Vermant
- Department of Materials, ETH Zurich, Switzerland.
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12
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Hu M, Shen X, Tran D, Ma Z, Isa L. Modular assembly of microswimmers with liquid compartments. J Phys Condens Matter 2023. [PMID: 37463595 DOI: 10.1088/1361-648x/ace871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Artificial microswimmers, i.e. colloidal scale objects capable of self-propulsion, have garnered significant attention due to their central role as models for out of equilibrium systems. Moreover, their potential applications in diverse fields such as biomedicine, environmental remediation, and materials science have long been hypothesized, often in conjunction with their ability to deliver cargoes to overcome mass transport limitations. A very efficient way to load molecular cargoes is to disperse them in a liquid, however, fabricating microswimmers with multiple liquid compartments remains a significant challenge. To address this challenge, we present a modular fabrication platform that combines microfluidic synthesis and sequential capillarity-assisted particle assembly (sCAPA) for microswimmers with various liquid compartments. We demonstrate the synthesis of monodisperse, small polymer-based microcapsules (Ø = 3 - 6 µm) with different liquid cargoes using a flow-focusing microfluidic device. By employing the sCAPA technique, we assemble multiple microcapsules into microswimmers with high precision, resulting in versatile microswimmers with multiple liquid compartments and programmable functionalities. Our work provides a flexible approach for the fabrication of modular microswimmers, which could potentially actively transport cargoes and release them on demand in the future.
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Affiliation(s)
- Minghan Hu
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, 8093, SWITZERLAND
| | - Xueting Shen
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, Zürich, 8093, SWITZERLAND
| | - Daniel Tran
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, Zürich, 8093, SWITZERLAND
| | - Zhongqi Ma
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, Zürich, 8093, SWITZERLAND
| | - Lucio Isa
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich, Zürich, 8093, SWITZERLAND
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13
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Plath AMS, Huber S, Alfarano SR, Abbott DF, Hu M, Mougel V, Isa L, Ferguson SJ. Co-Electrospun Poly(ε-Caprolactone)/Zein Articular Cartilage Scaffolds. Bioengineering (Basel) 2023; 10:771. [PMID: 37508797 PMCID: PMC10376865 DOI: 10.3390/bioengineering10070771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Osteoarthritis scaffold-based grafts fail because of poor integration with the surrounding soft tissue and inadequate tribological properties. To circumvent this, we propose electrospun poly(ε-caprolactone)/zein-based scaffolds owing to their biomimetic capabilities. The scaffold surfaces were characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, static water contact angles, and profilometry. Scaffold biocompatibility properties were assessed by measuring protein adsorption (Bicinchoninic Acid Assay), cell spreading (stained F-actin), and metabolic activity (PrestoBlue™ Cell Viability Reagent) of primary bovine chondrocytes. The data show that zein surface segregation in the membranes not only completely changed the hydrophobic behavior of the materials, but also increased the cell yield and metabolic activity on the scaffolds. The surface segregation is verified by the infrared peak at 1658 cm-1, along with the presence and increase in N1 content in the survey XPS. This observation could explain the decrease in the water contact angles from 125° to approximately 60° in zein-comprised materials and the decrease in the protein adsorption of both bovine serum albumin and synovial fluid by half. Surface nano roughness in the PCL/zein samples additionally benefited the radial spreading of bovine chondrocytes. This study showed that co-electrospun PCL/zein scaffolds have promising surface and biocompatibility properties for use in articular-tissue-engineering applications.
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Affiliation(s)
| | - Stephanie Huber
- Laboratory for Orthopaedic Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Serena R Alfarano
- Laboratory of Food and Soft Materials, ETH Zurich, 8092 Zurich, Switzerland
| | - Daniel F Abbott
- Laboratory of Inorganic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Minghan Hu
- Laboratory for Soft Materials and Interfaces, ETH Zurich, 8093 Zurich, Switzerland
| | - Victor Mougel
- Laboratory of Inorganic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, ETH Zurich, 8093 Zurich, Switzerland
| | - Stephen J Ferguson
- Laboratory for Orthopaedic Technology, ETH Zurich, 8092 Zurich, Switzerland
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14
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Bailey MR, Gmür TA, Grillo F, Isa L. Modular Attachment of Nanoparticles on Microparticle Supports via Multifunctional Polymers. Chem Mater 2023; 35:3731-3741. [PMID: 37181676 PMCID: PMC10173378 DOI: 10.1021/acs.chemmater.3c00555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/13/2023] [Indexed: 05/16/2023]
Abstract
Nanoparticles are key to a range of applications, due to the properties that emerge as a result of their small size. However, their size also presents challenges to their processing and use, especially in relation to their immobilization on solid supports without losing their favorable functionalities. Here, we present a multifunctional polymer-bridge-based approach to attach a range of presynthesized nanoparticles onto microparticle supports. We demonstrate the attachment of mixtures of different types of metal-oxide nanoparticles, as well as metal-oxide nanoparticles modified with standard wet chemistry approaches. We then show that our method can also create composite films of metal and metal-oxide nanoparticles by exploiting different chemistries simultaneously. We finally apply our approach to the synthesis of designer microswimmers with decoupled mechanisms of steering (magnetic) and propulsion (light) via asymmetric nanoparticle binding, aka Toposelective Nanoparticle Attachment. We envision that this ability to freely mix available nanoparticles to produce composite films will help bridge the fields of catalysis, nanochemistry, and active matter toward new materials and applications.
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15
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Niggel V, Bailey MR, van Baalen C, Zosso N, Isa L. 3-D rotation tracking from 2-D images of spherical colloids with textured surfaces. Soft Matter 2023; 19:3069-3079. [PMID: 37043248 PMCID: PMC10155603 DOI: 10.1039/d3sm00076a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Tracking the three-dimensional rotation of colloidal particles is essential to elucidate many open questions, e.g. concerning the contact interactions between particles under flow, or the way in which obstacles and neighboring particles affect self-propulsion in active suspensions. In order to achieve rotational tracking, optically anisotropic particles are required. We synthesise here rough spherical colloids that present randomly distributed fluorescent asperities and track their motion under different experimental conditions. Specifically, we propose a new algorithm based on a 3-D rotation registration, which enables us to track the 3-D rotation of our rough colloids at short time-scales, using time series of 2-D images acquired at high frame rates with a conventional wide-field microscope. The method is based on the image correlation between a reference image and rotated 3-D prospective images to identify the most likely angular displacements between frames. We first validate our approach against simulated data and then apply it to the cases of: particles flowing through a capillary, freely diffusing at solid-liquid and liquid-liquid interfaces, and self-propelling above a substrate. By demonstrating the applicability of our algorithm and sharing the code, we hope to encourage further investigations in the rotational dynamics of colloidal systems.
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Affiliation(s)
- Vincent Niggel
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Maximilian R Bailey
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Carolina van Baalen
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Nino Zosso
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
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16
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Yun HS, Meijs ZC, Park G, Fu Y, Isa L, Yoon DK. Controlling liquid crystal boojum defects on fixed microparticle arrays via capillarity-assisted particles assembly. J Colloid Interface Sci 2023; 645:115-121. [PMID: 37146375 DOI: 10.1016/j.jcis.2023.04.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/12/2023] [Accepted: 04/21/2023] [Indexed: 05/07/2023]
Abstract
HYPOTHESIS Colloidal particles in nematic liquid crystals (LCs) are of high interest for self-assembly of soft matter systems. When two free particles approach within a uniaxially-oriented nematic LC, an elastic force is generated due to the distorted nematic director configuration around them, allowing particles to self-assemble by an attractive force. We hypothesize that if particles are immobilized, repulsive forces emerge instead, causing the deflection of the interacting defects to compensate for the energy increase. EXPERIMENTS We fabricated tailored arrays of spherical silica microparticles via capillarity-assisted particle assembly (CAPA) to investigate the interactions of defects as a function of particle separation. By transferring the particle arrays from the CAPA templates to a glass substrate, we studied interacting boojum defect textures within thin LC films sandwiched between two substrates using polarized optical microscopy (POM). FINDINGS We observed deflected boojum defects on arrays of fixed silica particles, confirming our hypothesis that the elastic repulsive force between the particles affects the defect orientation. The nematic director configuration is reconstructed by Landau-de Gennes q-tensor modeling, and simulated POM images are obtained by the Jones-Matrix method. Our results provide a new platform for controlling defect interactions and pave the way for future work to study topology and implement new defect based applications in LC films.
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Affiliation(s)
- Hee Seong Yun
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Zazo Cazimir Meijs
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Geonhyeong Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Yutong Fu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland.
| | - Dong Ki Yoon
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea; Graduate School of Nanoscience and Technology and KAIST Institute for NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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17
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Ulbrich JA, Fernández-Rico C, Rost B, Vialetto J, Isa L, Urbach JS, Dullens RPA. Effect of curvature on the diffusion of colloidal bananas. Phys Rev E 2023; 107:L042602. [PMID: 37198802 DOI: 10.1103/physreve.107.l042602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/22/2023] [Indexed: 05/19/2023]
Abstract
Anisotropic colloidal particles exhibit complex dynamics which play a crucial role in their functionality, transport, and phase behavior. In this Letter, we investigate the two-dimensional diffusion of smoothly curved colloidal rods-also known as colloidal bananas-as a function of their opening angle α. We measure the translational and rotational diffusion coefficients of the particles with opening angles ranging from 0^{∘} (straight rods) to nearly 360^{∘}(closed rings). In particular, we find that the anisotropic diffusion of the particles varies nonmonotonically with their opening angle and that the axis of fastest diffusion switches from the long to the short axis of the particles when α>180^{∘}. We also find that the rotational diffusion coefficient of nearly closed rings is approximately an order of magnitude higher than that of straight rods of the same length. Finally, we show that the experimental results are consistent with slender body theory, indicating that the dynamical behavior of the particles arises primarily from their local drag anisotropy. These results highlight the impact of curvature on the Brownian motion of elongated colloidal particles, which must be taken into account when seeking to understand the behavior of curved colloidal particles.
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Affiliation(s)
- Justin-Aurel Ulbrich
- Department of Chemistry, Physical and Theoretical Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
- Department of Materials, ETH Zürich, 8093 Zurich, Switzerland
| | - Carla Fernández-Rico
- Department of Chemistry, Physical and Theoretical Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
- Department of Materials, ETH Zürich, 8093 Zurich, Switzerland
| | - Brian Rost
- Department of Physics and Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA
| | - Jacopo Vialetto
- Department of Materials, ETH Zürich, 8093 Zurich, Switzerland
| | - Lucio Isa
- Department of Materials, ETH Zürich, 8093 Zurich, Switzerland
| | - Jeffrey S Urbach
- Department of Physics and Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA
| | - Roel P A Dullens
- Department of Chemistry, Physical and Theoretical Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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18
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Zhao K, Hu M, van Baalen C, Alvarez L, Isa L. Sorting of heterogeneous colloids by AC-dielectrophoretic forces in a microfluidic chip with asymmetric orifices. J Colloid Interface Sci 2023; 634:921-929. [PMID: 36571855 DOI: 10.1016/j.jcis.2022.12.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
HYPOTHESIS The synthesis of compositionally heterogeneous particles is central to the development of complex colloidal units for self-assembly and self-propulsion. Yet, as the complexity of particles grows, synthesis becomes more prone to "errors". We hypothesize that alternating-current dielectrophoretic forces can efficiently sort Janus particles, as a function of patch size and material, and colloidal dumbbells by size. EXPERIMENTS We prepared Janus particles with different patch size and material by physical vapor deposition and colloidal dumbbells via capillarity-assisted particle assembly. We then performed sorting experiments in a microfluidic chip comprising electrodes with asymmetric orifices, specifically exploiting the dielectric contrast between different portions of the particles or their size difference to steer them towards different outlets. FINDINGS We calculated that the DEP force for Janus particles may switch from positive to negative as a function of composition at a critical AC frequency, thus enabling sorting different particles crossing the electrodes' region. The predictions are confirmed by optical microscopy experiments. We also show that intact and "broken" dumbbells can be simply separated as they experience different DEP forces. The integration of multiple asymmetric orifices leads a larger zone with high field gradient to increase separation efficiency and makes it a promising tool to select precise particle populations, isolating fractions with narrowly distributed characteristics.
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Affiliation(s)
- Kai Zhao
- Liaoning Key Laboratory of Marine Sensing and Intelligent Detection, Department of Information Science and Technology, Dalian Maritime University, 116026 Dalian, China; Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
| | - Minghan Hu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Carolina van Baalen
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Laura Alvarez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
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19
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van Kesteren S, Shen X, Aldeghi M, Isa L. Printing on Particles: Combining Two-Photon Nanolithography and Capillary Assembly to Fabricate Multimaterial Microstructures. Adv Mater 2023; 35:e2207101. [PMID: 36601964 DOI: 10.1002/adma.202207101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 12/20/2022] [Indexed: 05/16/2023]
Abstract
Additive manufacturing at the micro- and nanoscale has seen a recent upsurge to suit an increasing demand for more elaborate structures. However, the integration of multiple distinct materials at small scales remains challenging. To this end, capillarity-assisted particle assembly (CAPA) and two-photon polymerization direct laser writing (2PP-DLW) are combined to realize a new class of multimaterial microstructures. 2PP-DLW and CAPA both are used to fabricate 3D templates to guide the CAPA of soft- and hard colloids, and to link well-defined arrangements of functional microparticle arrays produced by CAPA, a process that is termed "printing on particles." The printing process uses automated particle recognition algorithms to connect colloids into 1D, 2D, and 3D tailored structures, via rigid, soft, or responsive polymer links. Once printed and developed, the structures can be easily re-dispersed in water. Particle clusters and lattices of varying symmetry and composition are reported, together with thermoresponsive microactuators, and magnetically driven "micromachines", which can efficiently move, capture, and release DNA-coated particles in solution. The flexibility of this method allows the combination of a wide range of functional materials into complex structures, which will boost the realization of new systems and devices for numerous fields, including microrobotics, micromanipulation, and metamaterials.
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Affiliation(s)
- Steven van Kesteren
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zurich, 8093, Switzerland
| | - Xueting Shen
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zurich, 8093, Switzerland
| | - Michele Aldeghi
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zurich, 8093, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zurich, 8093, Switzerland
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20
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Araújo NAM, Janssen LMC, Barois T, Boffetta G, Cohen I, Corbetta A, Dauchot O, Dijkstra M, Durham WM, Dussutour A, Garnier S, Gelderblom H, Golestanian R, Isa L, Koenderink GH, Löwen H, Metzler R, Polin M, Royall CP, Šarić A, Sengupta A, Sykes C, Trianni V, Tuval I, Vogel N, Yeomans JM, Zuriguel I, Marin A, Volpe G. Steering self-organisation through confinement. Soft Matter 2023; 19:1695-1704. [PMID: 36779972 PMCID: PMC9977364 DOI: 10.1039/d2sm01562e] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Self-organisation is the spontaneous emergence of spatio-temporal structures and patterns from the interaction of smaller individual units. Examples are found across many scales in very different systems and scientific disciplines, from physics, materials science and robotics to biology, geophysics and astronomy. Recent research has highlighted how self-organisation can be both mediated and controlled by confinement. Confinement is an action over a system that limits its units' translational and rotational degrees of freedom, thus also influencing the system's phase space probability density; it can function as either a catalyst or inhibitor of self-organisation. Confinement can then become a means to actively steer the emergence or suppression of collective phenomena in space and time. Here, to provide a common framework and perspective for future research, we examine the role of confinement in the self-organisation of soft-matter systems and identify overarching scientific challenges that need to be addressed to harness its full scientific and technological potential in soft matter and related fields. By drawing analogies with other disciplines, this framework will accelerate a common deeper understanding of self-organisation and trigger the development of innovative strategies to steer it using confinement, with impact on, e.g., the design of smarter materials, tissue engineering for biomedicine and in guiding active matter.
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Affiliation(s)
- Nuno A M Araújo
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
- Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Liesbeth M C Janssen
- Department of Applied Physics and Science Education, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
- Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Thomas Barois
- University of Bordeaux, CNRS, LOMA, UMR 5798, F-33400, Talence, France
| | - Guido Boffetta
- Department of Physics and INFN, University of Torino, via Pietro Giuria 1, 10125, Torino, Italy
| | - Itai Cohen
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York, USA
- Laboratory of Atomic and Solid-State Physics, Cornell University, Ithaca, New York, USA
| | - Alessandro Corbetta
- Department of Applied Physics and Science Education, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
| | - Olivier Dauchot
- Gulliver UMR CNRS 7083, ESPCI Paris, Université PSL, 75005, Paris, France
| | - Marjolein Dijkstra
- Soft condensed matter, Department of Physics, Debye institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC, Utrecht, The Netherlands
| | - William M Durham
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK
| | - Audrey Dussutour
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, 31062, AD, France
| | - Simon Garnier
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Hanneke Gelderblom
- Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
- Department of Applied Physics and J. M. Burgers Center for Fluid Dynamics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS), 37077, Göttingen, Germany
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, OX1 3PU, UK
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093, Zürich, Switzerland
| | - Gijsje H Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Ralf Metzler
- Institute of Physics & Astronomy, University of Potsdam, Karl-Liebknecht-Str 24/25, D-14476, Potsdam-Golm, Germany
| | - Marco Polin
- Mediterranean Institute for Advanced Studies, IMEDEA UIB-CSIC, C/Miquel Marqués 21, 07190, Esporles, Spain
- Department of Physics, University of Warwick, Gibbet Hill road, CV4 7AL, Coventry, UK
| | - C Patrick Royall
- Gulliver UMR CNRS 7083, ESPCI Paris, Université PSL, 75005, Paris, France
| | - Anđela Šarić
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - Anupam Sengupta
- Physics of Living Matter, Department of Physics and Materials Science, University of Luxembourg, 162 A, Avenue de la Faïencerie, L-1511, Luxembourg
| | - Cécile Sykes
- Laboratoire de Physique de lÉcole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - Vito Trianni
- Institute of Cognitive Sciences and Technologies, CNR, Via San Martino della Battaglia 44, 00185, Rome, Italy
| | - Idan Tuval
- Mediterranean Institute for Advanced Studies, IMEDEA UIB-CSIC, C/Miquel Marqués 21, 07190, Esporles, Spain
| | - Nicolas Vogel
- Institute of Particle Technology, Friedrich-Alexander Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Julia M Yeomans
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, OX1 3PU, UK
| | - Iker Zuriguel
- Departamento de Física y Matemática Aplicada, Facultad de Ciencias, Universidad de Navarra, Pamplona, Spain
| | - Alvaro Marin
- Physics of Fluids Group, Mesa+ Institute, Max Planck Center for Complex Fluid Dynamics and J. M. Burgers Center for Fluid Dynamics, University of Twente, 7500AE, Enschede, The Netherlands.
| | - Giorgio Volpe
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
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Vialetto J, Ramakrishna SN, Isa L. In situ imaging of the three-dimensional shape of soft responsive particles at fluid interfaces by atomic force microscopy. Sci Adv 2022; 8:eabq2019. [PMID: 36351021 PMCID: PMC9645722 DOI: 10.1126/sciadv.abq2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The reconfiguration of individual soft and deformable particles upon adsorption at a fluid interface underpins many aspects of their dynamics and interactions, ultimately regulating the properties of monolayers of relevance for applications. In this work, we demonstrate that atomic force microscopy can be used for the in situ reconstruction of the three-dimensional conformation of model poly(N-isopropylacrylamide) microgels adsorbed at an oil-water interface. We image the particle topography from both sides of the interface to characterize its in-plane deformation and to visualize the occurrence of asymmetric swelling in the two fluids. In addition, the technique enables investigating different fluid phases and particle architectures, as well as studying the effect of temperature variations on particle conformation in situ. We envisage that these results open up an exciting range of possibilities to provide microscopic insights into the single-particle behavior of soft objects at fluid interfaces and into the resulting macroscopic material properties.
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Affiliation(s)
| | | | - Lucio Isa
- Corresponding author. (J.V.); (S.N.R.); (L.I.)
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22
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Bailey MR, Sprenger AR, Grillo F, Löwen H, Isa L. Fitting an active Brownian particle's mean-squared displacement with improved parameter estimation. Phys Rev E 2022; 106:L052602. [PMID: 36559483 DOI: 10.1103/physreve.106.l052602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/03/2022] [Indexed: 11/23/2022]
Abstract
The active Brownian particle (ABP) model is widely used to describe the dynamics of active matter systems, such as Janus microswimmers. In particular, the analytical expression for an ABP's mean-squared displacement (MSD) is useful as it provides a means to describe the essential physics of a self-propelled, spherical Brownian particle. However, the truncated or "short-time" form of the MSD equation is typically fitted, which can lead to significant problems in parameter estimation. Furthermore, heteroscedasticity and the often statistically dependent observations of an ABP's MSD lead to a situation where standard ordinary least-squares regression leads to biased estimates and unreliable confidence intervals. Instead, we propose here to revert to always fitting the full expression of an ABP's MSD at short timescales, using bootstrapping to construct confidence intervals of the fitted parameters. Additionally, after comparison between different fitting strategies, we propose to extract the physical parameters of an ABP using its mean logarithmic squared displacement. These steps improve the estimation of an ABP's physical properties and provide more reliable confidence intervals, which are critical in the context of a growing interest in the interactions of microswimmers with confining boundaries and the influence on their motion.
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Affiliation(s)
- Maximilian R Bailey
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Alexander R Sprenger
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany.,Institut für Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Fabio Grillo
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
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23
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Del Mastro L, Poggio F, Blondeaux E, De Placido S, Giuliano M, Forestieri V, De Laurentiis M, Gravina A, Bisagni G, Rimanti A, Turletti A, Nisticò C, Vaccaro A, Cognetti F, Fabi A, Gasparro S, Garrone O, Alicicco MG, Urracci Y, Mansutti M, Poletti P, Correale P, Bighin C, Puglisi F, Montemurro F, Colantuoni G, Lambertini M, Boni L, Venturini M, Abate A, Pastorino S, Canavese G, Vecchio C, Guenzi M, Lambertini M, Levaggi A, Giraudi S, Accortanzo V, Floris C, Aitini E, Fornari G, Miraglia S, Buonfanti G, Cherchi M, Petrelli F, Vaccaro A, Magnolfi E, Contu A, Labianca R, Parisi A, Basurto C, Cappuzzo F, Merlano M, Russo S, Mansutti M, Poletto E, Nardi M, Grasso D, Fontana A, Isa L, Comandè M, Cavanna L, Iacobelli S, Milani S, Mustacchi G, Venturini S, Scinto A, Sarobba M, Pugliese P, Bernardo A, Pavese I, Coccaro M, Massidda B, Ionta M, Nuzzo A, Laudadio L, Chiantera V, Dottori R, Barduagni M, Castiglione F, Ciardiello F, Tinessa V, Ficorella A, Moscetti L, Vallini I, Giardina G, Silva R, Montedoro M, Seles E, Morano F, Cruciani G, Adamo V, Pancotti A, Palmisani V, Ruggeri A, Cammilluzzi E, Carrozza F, D'Aprile M, Brunetti M, Gallotti P, Chiesa E, Testore F, D'Arco A, Ferro A, Jirillo A, Pezzoli M, Scambia G, Iacono C, Masullo P, Tomasello G, Gandini G, Zoboli A, Bottero C, Cazzaniga M, Genua G, Palazzo S, D'Amico M, Perrone D. Fluorouracil and dose-dense adjuvant chemotherapy in patients with early-stage breast cancer (GIM2): end-of-study results from a randomised, phase 3 trial. Lancet Oncol 2022; 23:1571-1582. [DOI: 10.1016/s1470-2045(22)00632-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 11/11/2022]
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24
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Niggel V, Hsu CP, Isa L. Dynamically shaping the surface of silica colloids. Soft Matter 2022; 18:7794-7803. [PMID: 36193704 DOI: 10.1039/d2sm00842d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Surface roughness is an important design parameter to influence the processing of particle-based materials. Current methods to synthesize rough particles present some limitations, e.g. low yield, relative methodological complexity, requirements of multiple steps, or poor roughness control. Here, we thoroughly investigate a facile synthesis route where two silanes, tetraethyl orthosilicate (TEOS) and vinyltrimethoxysilane (VTMS), are added in one pot to form silica particles with controlled corrugated surfaces. We first show that the morphology of these particles can be defined by regulating the amount and ratio of the two silane precursors and by adjusting the concentration of ammonia during synthesis. We characterize the surface topography of the particles using atomic force microscopy and show a direct correlation between surface roughness and the synthesis conditions. Furthermore, we carry out an in situ observation of the evolution of surface morphology and propose a mechanism for surface structuring that hinges on the formation of silane droplets, followed by the preferential hydrolysis/condensation reaction of VTMS starting from the droplet surface and evolving towards the center. The exchange of liquid from the droplets through the VTMS shell leads to stress accumulation and wrinkling/buckling of the particles. Moreover, we explicitly show that osmotic imbalances between the inside and the outside of the droplets regulate their shrinking. We therefore demonstrate that exchanging solvents has a comparable impact to adjusting silane and ammonia content in defining the particle shape and that this synthesis route is highly dynamical. Finally, we demonstrate that it is possible to incorporate fluorescent dyes during synthesis to enable future studies on the impact of surface roughness on dynamic processes, including shear, via direct high-resolution imaging. Our findings show that the mechanism for wrinkling and buckling in colloidal silica particles follows a general scheme found in a broad range of systems, from liposomes and polymeric capsules to Pickering emulsion droplets.
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Affiliation(s)
- Vincent Niggel
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Chiao-Peng Hsu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, CH-8093, Zurich, Switzerland.
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25
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Abstract
Advancements in artificial active matter systems heavily rely on our ability to characterise their motion. Yet, the most widely used tool to analyse the latter is standard wide-field microscopy, which is largely limited to the study of two-dimensional motion. In contrast, real-world applications often require the navigation of complex three-dimensional environments. Here, we present a Machine Learning (ML) approach to track Janus microswimmers in three dimensions, using Z-stacks as labelled training data. We demonstrate several examples of ML algorithms using freely available and well-documented software, and find that an ensemble Decision Tree-based model (Extremely Randomised Decision Trees) performs the best at tracking the particles over a volume spanning more than 40 μm. With this model, we are able to localise Janus particles with a significant optical asymmetry from standard wide-field microscopy images, bypassing the need for specialised equipment and expertise such as that required for digital holographic microscopy. We expect that ML algorithms will become increasingly prevalent by necessity in the study of active matter systems, and encourage experimentalists to take advantage of this powerful tool to address the various challenges within the field.
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Affiliation(s)
- Maximilian Robert Bailey
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Fabio Grillo
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
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26
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Hu M, Reichholf N, Xia Y, Alvarez L, Cao X, Ma S, deMello AJ, Isa L. Multi-compartment supracapsules made from nano-containers towards programmable release. Mater Horiz 2022; 9:1641-1648. [PMID: 35466981 DOI: 10.1039/d2mh00135g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The assembly of nanomaterials into suprastructures offers the possibility to fabricate larger scale functional materials, whose inner structure strongly influences their functionality for a vast range of applications. In spite of the many current strategies, achieving multi-compartment structures in a targeted and versatile way remains highly challenging. Here, we describe a controllable and straightforward route to create uniform suprastructured materials with a multi-compartmentalized architecture by confining primary nanocapsules into droplets using a cross-junction microfluidic device. Following solvent evaporation from the droplets, the nanocapsules spontaneously assemble into precisely sized multi-compartment particles, which we term supracapsules. Thanks to the process, each spatially separated nanocapsule unit retains its cargo and functionalities within the resulting supracapsules. However, new collective properties emerge, and, particularly, programmable release profiles that are distinct from those of single-compartment capsules. Finally, the suprastructures can be disassembled into single-compartment units by applying ultra-sonication, switching their release to a burst-release mode. These findings open up exciting opportunities to fabricate multi-compartment suprastructures incorporating diverse functionalities for materials with emerging properties.
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Affiliation(s)
- Minghan Hu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Nico Reichholf
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Yanming Xia
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen, Fujian, China
| | - Laura Alvarez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Xiaobao Cao
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland
| | - Shenglin Ma
- Department of Mechanical & Electrical Engineering, Xiamen University, Xiamen, Fujian, China
| | - Andrew J deMello
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
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27
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Nussbaum N, Bergfreund J, Vialetto J, Isa L, Fischer P. Microgels as globular protein model systems. Colloids Surf B Biointerfaces 2022; 217:112595. [PMID: 35665640 DOI: 10.1016/j.colsurfb.2022.112595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/06/2022] [Accepted: 05/22/2022] [Indexed: 11/30/2022]
Abstract
Understanding globular protein adsorption to fluid interfaces, their interfacial assembly, and structural reorganization is not only important in the food industry, but also in medicine and biology. However, due to their intrinsic structural complexity, a unifying description of these phenomena remains elusive. Herein, we propose N-isopropylacrylamide microgels as a promising model system to isolate different aspects of adsorption, dilatational rheology, and interfacial structure at fluid interfaces with a wide range of interfacial tensions, and compare the results with the ones of globular proteins. In particular, the steady-state spontaneously-adsorbed interfacial pressure of microgels correlates closely to that of globular proteins, following the same power-law behavior as a function of the initial surface tension. However, the dilatational rheology of spontaneously-adsorbed microgel layers is dominated by the presence of a loosely packed polymer corona spread at the interface, and it thus exhibits a similar mechanical response as flexible, unstructured proteins, which are significantly weaker than globular ones. Finally, structurally, microgels reveal a similar spreading and flattening upon adsorption as globular proteins do. In conclusion, microgels offer interesting opportunities to act as powerful model systems to unravel the complex behavior of proteins at fluid interfaces.
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Affiliation(s)
- Natalie Nussbaum
- Institute of Food, Nutrition and Health, ETH Zürich, Zürich 8092, Switzerland
| | - Jotam Bergfreund
- Institute of Food, Nutrition and Health, ETH Zürich, Zürich 8092, Switzerland
| | - Jacopo Vialetto
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich 8093, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich 8093, Switzerland
| | - Peter Fischer
- Institute of Food, Nutrition and Health, ETH Zürich, Zürich 8092, Switzerland.
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28
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Vialetto J, Zanini M, Isa L. Attachment and detachment of particles to and from fluid interfaces. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2021.101560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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29
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Vialetto J, Nussbaum N, Bergfreund J, Fischer P, Isa L. Influence of the interfacial tension on the microstructural and mechanical properties of microgels at fluid interfaces. J Colloid Interface Sci 2022; 608:2584-2592. [PMID: 34774321 DOI: 10.1016/j.jcis.2021.10.186] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/21/2021] [Accepted: 10/29/2021] [Indexed: 10/19/2022]
Abstract
Microgels are soft colloidal particles constituted by cross-linked polymer networks with a high potential for applications. In particular, after adsorption at a fluid interface, interfacial tension provides two-dimensional (2D) confinement for microgel monolayers and drives the reconfiguration of the particles, enabling their deployment in foam and emulsion stabilization and in surface patterning for lithography, sensing and optical materials. However, most studies focus on systems of fluids with a high interfacial tension, e.g. alkanes/ or air/water interfaces, which imparts similar properties to the assembled monolayers. Here, instead, we compare two organic fluid phases, hexane and methyl tert-butyl ether, which have markedly different interfacial tension (γ) values with water and thus tune the deformation of adsorbed microgels. We rationalize how γ controls the single-particle morphology, which consequently modulates the structural and mechanical response of the monolayers at varying interfacial compression. Specifically, when γ is low, the microgels are less deformed within the interface plane and their polymer networks can rearrange more easily upon lateral compression, leading to softer monolayers. Selecting interfaces with different surface energy offers an additional control to customize the 2D assembly of soft particles, from the fine-tuning of particle size and interparticle spacing to the tailoring of mechanical properties.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Natalie Nussbaum
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Jotam Bergfreund
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Peter Fischer
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
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30
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Pioli R, Stocker R, Isa L, Secchi E. Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly. J Vis Exp 2021. [PMID: 34806699 DOI: 10.3791/63131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Controlled patterning of microorganisms into defined spatial arrangements offers unique possibilities for a broad range of biological applications, including studies of microbial physiology and interactions. At the simplest level, accurate spatial patterning of microorganisms would enable reliable, long-term imaging of large numbers of individual cells and transform the ability to quantitatively study distance-dependent microbe-microbe interactions. More uniquely, coupling accurate spatial patterning and full control over environmental conditions, as offered by microfluidic technology, would provide a powerful and versatile platform for single-cell studies in microbial ecology. This paper presents a microfluidic platform to produce versatile and user-defined patterns of microorganisms within a microfluidic channel, allowing complete optical access for long-term, high-throughput monitoring. This new microfluidic technology is based on capillarity-assisted particle assembly and exploits the capillary forces arising from the controlled motion of an evaporating suspension inside a microfluidic channel to deposit individual microsized objects in an array of traps microfabricated onto a polydimethylsiloxane (PDMS) substrate. Sequential depositions generate the desired spatial layout of single or multiple types of micro-sized objects, dictated solely by the geometry of the traps and the filling sequence. The platform has been calibrated using colloidal particles of different dimensions and materials: it has proven to be a powerful tool to generate diverse colloidal patterns and perform surface functionalization of trapped particles. Furthermore, the platform was tested on microbial cells, using Escherichia coli cells as a model bacterium. Thousands of individual cells were patterned on the surface, and their growth was monitored over time. In this platform, the coupling of single-cell deposition and microfluidic technology allows both geometric patterning of microorganisms and precise control of environmental conditions. It thus opens a window into the physiology of single microbes and the ecology of microbe-microbe interactions, as shown by preliminary experiments.
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Affiliation(s)
- Roberto Pioli
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich
| | | | - Eleonora Secchi
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich;
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31
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Vialetto J, Camerin F, Grillo F, Ramakrishna SN, Rovigatti L, Zaccarelli E, Isa L. Effect of Internal Architecture on the Assembly of Soft Particles at Fluid Interfaces. ACS Nano 2021; 15:13105-13117. [PMID: 34328717 PMCID: PMC8388124 DOI: 10.1021/acsnano.1c02486] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Monolayers of soft colloidal particles confined at fluid interfaces are at the core of a broad range of technological processes, from the stabilization of responsive foams and emulsions to advanced lithographic techniques. However, establishing a fundamental relation between their internal architecture, which is controlled during synthesis, and their structural and mechanical properties upon interfacial confinement remains an elusive task. To address this open issue, which defines the monolayer's properties, we synthesize core-shell microgels, whose soft core can be chemically degraded in a controlled fashion. This strategy allows us to obtain a series of particles ranging from analogues of standard batch-synthesized microgels to completely hollow ones after total core removal. Combined experimental and numerical results show that our hollow particles have a thin and deformable shell, leading to a temperature-responsive collapse of the internal cavity and a complete flattening after adsorption at a fluid interface. Mechanical characterization shows that a critical degree of core removal is required to obtain soft disk-like particles at an oil-water interface, which present a distinct response to compression. At low packing fractions, the mechanical response of the monolayer is dominated by the outer polymer chains forming a corona surrounding the particles within the interfacial plane, regardless of the presence of a core. By contrast, at high compression, the absence of a core enables the particles to deform in the direction orthogonal to the interface and to be continuously compressed without altering the monolayer structure. These findings show how fine, single-particle architectural control during synthesis can be engineered to determine the interfacial behavior of microgels, enabling one to link particle conformation with the resulting material properties.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Fabrizio Camerin
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Basic and Applied Sciences for Engineering, Sapienza University of Rome, via A. Scarpa 14, 00161 Roma, Italy
| | - Fabio Grillo
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Shivaprakash N. Ramakrishna
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Lorenzo Rovigatti
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185 Roma, Italy
| | - Emanuela Zaccarelli
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185 Roma, Italy
| | - Lucio Isa
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
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32
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Hsu CP, Baysal HE, Wirenborn G, Mårtensson G, Prahl Wittberg L, Isa L. Roughness-dependent clogging of particle suspensions flowing into a constriction. Soft Matter 2021; 17:7252-7259. [PMID: 34318863 DOI: 10.1039/d1sm00738f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
When concentrated particle suspensions flow into a constricting channel, the suspended particles may either smoothly flow through the constriction or jam and clog the channel. These clogging events are typically detrimental to technological processes, such as in the printing of dense pastes or in filtration, but can also be exploited in micro-separation applications. Many studies have to date focused on important parameters influencing the occurrence of clogs, such as flow velocity, particle concentration, and channel geometry. However, the investigation of the role played by the particle surface properties has surprisingly received little attention so far. Here, we study the effect of surface roughness on the clogging of suspensions of silica particles under pressure-driven flows along a microchannel presenting a constriction. We synthesize micron-sized particles with uniform surface chemistry and tunable roughness and determine the occurrence of clogging events as a function of velocity and volume fraction for a given surface topography. Our results show that there is a clear correlation between surface roughness and flow rate, indicating that rougher particles are more likely to jam at the constriction for slower flows. These findings identify surface roughness as an essential parameter to consider in the formulation of particulate suspensions for applications where clogging plays an important role.
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Affiliation(s)
- Chiao-Peng Hsu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland.
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33
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Alvarez L, Fernandez-Rodriguez MA, Alegria A, Arrese-Igor S, Zhao K, Kröger M, Isa L. Reconfigurable artificial microswimmers with internal feedback. Nat Commun 2021; 12:4762. [PMID: 34362934 PMCID: PMC8346629 DOI: 10.1038/s41467-021-25108-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 07/17/2021] [Indexed: 11/09/2022] Open
Abstract
Self-propelling microparticles are often proposed as synthetic models for biological microswimmers, yet they lack the internally regulated adaptation of their biological counterparts. Conversely, adaptation can be encoded in larger-scale soft-robotic devices but remains elusive to transfer to the colloidal scale. Here, we create responsive microswimmers, powered by electro-hydrodynamic flows, which can adapt their motility via internal reconfiguration. Using sequential capillary assembly, we fabricate deterministic colloidal clusters comprising soft thermo-responsive microgels and light-absorbing particles. Light absorption induces preferential local heating and triggers the volume phase transition of the microgels, leading to an adaptation of the clusters' motility, which is orthogonal to their propulsion scheme. We rationalize this response via the coupling between self-propulsion and variations of particle shape and dielectric properties upon heating. Harnessing such coupling allows for strategies to achieve local dynamical control with simple illumination patterns, revealing exciting opportunities for developing tactic active materials.
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Affiliation(s)
- L Alvarez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland.
| | - M A Fernandez-Rodriguez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland
- Biocolloid and Fluid Physics Group, Applied Physics Department, Faculty of Sciences, University of Granada, Granada, Spain
| | - A Alegria
- Centro de Física de Materiales (CSIC-UPV/EHU), Materials Physics Center, San Sebastián, Spain
| | - S Arrese-Igor
- Centro de Física de Materiales (CSIC-UPV/EHU), Materials Physics Center, San Sebastián, Spain
| | - K Zhao
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - M Kröger
- Polymer Physics, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland.
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Young E, Argibay SG, Isa L, Zappacost. Villarroel MP, Inza R, Valcarcel A. P–717 Where do cryopreserved embryos end up after a positive pregnancy test? Hum Reprod 2021. [DOI: 10.1093/humrep/deab130.716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Study question
What is the destination of supernumerary embryos after a positive pregnancy test?
Summary answer
Half of the surplus cryopreserved embryos in assisted reproduction treatments are not transferred.
What is known already
Many of the surpernumerary cryopreserved embryos in assisted reproductive technologies are not transferred. This is a constant issue in many fertility centers around the world. Our objective was to report what happens with vitried surplus embryos after IVF in patients with a positive pregnancy test, carrying out an analysis according to age and final evolution of the pregnancy.
Study design, size, duration
This is a retrospective descriptive study. We analyzed 245 embryo transfer cycles, performed between January 2013 to December 2017, in 235 patients with a positive pregnancy test and who vitrified surplus embryos.
Participants/materials, setting, methods
All the patients underwent treatment with their own oocytes. The variables studied were: age, miscarriage rate (MR) and live birth rate (LBR). We compared the destination of the cryopreserved embryos according to the patient’s age and pregnancy evolution. Statistical analysis was performed with Fisher’s exact test.
Main results and the role of chance
20% of the IVF cycles (n = 49) were performed in women older than 40 years, 42% between 35 and 39 (n = 103) and 38% in women younger than 35 (n = 94). Average age was 35.8 ± 4.1 years. 859 embryos were cryopreserved (3.5 ± 1.9 cryopreserved embryos/patient). Average search time for surplus embryos was 20.5 ± 17.9 months, rising to 36.9 ± 14.9 months after delivery and decreasing to 8.7 ± 7.8 months after miscarriage (P < 0.0001). Up to date there are 118 (48.2%) patients whose cryopreserved embryos have not been transferred yet. Signficant differences were found in the three groups in using the cryopreserved embryos according to whether or not they had delivery. Almost half of the surplus cryopreserved embryos are not transferred. Regardless of the age of the patient, all groups showed the same behavior regarding the utilization of the cryopreserved embryos after delivery. It is essential to advise couples who perform assisted reproductive technologies, with a good probability of success (regardless of the patient’s age), about the responsibility that embryonic cryopreservation entails. Argentine legislation has limitations regarding the availability of cryopreserved surplus embryos.
Limitations, reasons for caution
This is a retrospective study.
Wider implications of the findings: We believe that Public Health policies related to this issue should be re evaluated based on these results.
Trial registration number
Not applicable
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Affiliation(s)
- E Young
- IFER, Reproductive Medicine, Ciudad Autonoma de Buenos Aires, Argentina
| | - S Garci Argibay
- IFER, Reproductive Medicine, Ciudad Autonoma de Buenos Aires, Argentina
| | - L Isa
- IFER, Reproductive Medicine, Ciudad Autonoma de Buenos Aires, Argentina
| | | | - R Inza
- IFER, Reproductive Medicine, Ciudad Autonoma de Buenos Aires, Argentina
| | - A Valcarcel
- IFER, Embryology, Ciudad Autonoma de Buenos Aires, Argentina
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35
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Pioli R, Fernandez-Rodriguez MA, Grillo F, Alvarez L, Stocker R, Isa L, Secchi E. Sequential capillarity-assisted particle assembly in a microfluidic channel. Lab Chip 2021; 21:888-895. [PMID: 33427254 DOI: 10.1039/d0lc00962h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Colloidal patterning enables the placement of a wide range of materials into prescribed spatial arrangements, as required in a variety of applications, including micro- and nano-electronics, sensing, and plasmonics. Directed colloidal assembly methods, which exploit external forces to place particles with high yield and great accuracy, are particularly powerful. However, currently available techniques require specialized equipment, which limits their applicability. Here, we present a microfluidic platform to produce versatile colloidal patterns within a microchannel, based on sequential capillarity-assisted particle assembly (sCAPA). This new microfluidic technology exploits the capillary forces resulting from the controlled motion of an evaporating droplet inside a microfluidic channel to deposit individual particles in an array of traps microfabricated onto a substrate. Sequential depositions allow the generation of a desired spatial layout of colloidal particles of single or multiple types, dictated solely by the geometry of the traps and the filling sequence. We show that the platform can be used to create a variety of patterns and that the microfluidic channel easily allows surface functionalization of trapped particles. By enabling colloidal patterning to be carried out in a controlled environment, exploiting equipment routinely used in microfluidics, we demonstrate an easy-to-build platform that can be implemented in microfluidics labs.
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Affiliation(s)
- Roberto Pioli
- Institute of Environmental Engineering, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, Stefano-Franscini-Platz 5, 8093 Zürich, Switzerland.
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Hsu CP, Mandal J, Ramakrishna SN, Spencer ND, Isa L. Exploring the roles of roughness, friction and adhesion in discontinuous shear thickening by means of thermo-responsive particles. Nat Commun 2021; 12:1477. [PMID: 33674607 PMCID: PMC7935878 DOI: 10.1038/s41467-021-21580-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 01/24/2021] [Indexed: 01/31/2023] Open
Abstract
Dense suspensions of colloidal or granular particles can display pronounced non-Newtonian behaviour, such as discontinuous shear thickening and shear jamming. The essential contribution of particle surface roughness and adhesive forces confirms that stress-activated frictional contacts can play a key role in these phenomena. Here, by employing a system of microparticles coated by responsive polymers, we report experimental evidence that the relative contributions of friction, adhesion, and surface roughness can be tuned in situ as a function of temperature. Modifying temperature during shear therefore allows contact conditions to be regulated, and discontinuous shear thickening to be switched on and off on demand. The macroscopic rheological response follows the dictates of independent single-particle characterization of adhesive and tribological properties, obtained by colloidal-probe atomic force microscopy. Our findings identify additional routes for the design of smart non-Newtonian fluids and open a way to more directly connect experiments to computational models of sheared suspensions.
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Affiliation(s)
- Chiao-Peng Hsu
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Joydeb Mandal
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland
| | | | - Nicholas D Spencer
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zurich, Zurich, Switzerland.
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Fernandez-Rodriguez MA, Antonopoulou MN, Isa L. Near-zero surface pressure assembly of rectangular lattices of microgels at fluid interfaces for colloidal lithography. Soft Matter 2021; 17:335-340. [PMID: 33355590 DOI: 10.1039/d0sm01823f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding and engineering the self-assembly of soft colloidal particles (microgels) at liquid-liquid interfaces is broadening their use in colloidal lithography. Here, we present a new route to assemble rectangular lattices of microgels at near zero surface pressure relying on the balance between attractive quadrupolar capillary interactions and steric repulsion among the particles at water/oil interfaces. These self-assembled rectangular lattices are obtained for a broad range of particles and, after deposition, can be used as lithography masks to obtain regular arrays of vertically aligned nanowires via wet and dry etching processes.
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Affiliation(s)
- Miguel Angel Fernandez-Rodriguez
- Laboratory of Surface and Interface Physics, Biocolloids and Fluid Physics group, Faculty of Sciences, University of Granada, Campus de Fuentenueva s/n, ES 18071 Granada, Spain. and Laboratory for Soft Materials and Interfaces, Swiss Federal Institute of Technology Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Maria-Nefeli Antonopoulou
- Laboratory for Soft Materials and Interfaces, Swiss Federal Institute of Technology Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Swiss Federal Institute of Technology Zürich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
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38
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Abstract
Control over the surface roughness of colloidal particles offers exciting opportunities to tailor the properties and the processing of a broad range of soft matter systems. Moreover, identifying surface roughness as a design parameter reveals the possibility to connect seemingly distinct phenomena and materials via the role played by roughness effects. In this feature article, we concisely review some approaches to synthesize and characterize rough colloidal particles, with a focus on model spherical colloids. We then discuss the impact that surface roughness has on both the high-shear rheology of dense suspensions and the stabilization of Pickering emulsions. Commenting on developments of our own research, we aim to offer an original perspective for a property-oriented development of colloidal particles that transcends classical divisions between materials and processes toward innovative solutions.
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Affiliation(s)
- Minghan Hu
- Department of Materials ETH Zurich, Laboratory for Soft Materials and Interfaces, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Chiao-Peng Hsu
- Department of Materials ETH Zurich, Laboratory for Soft Materials and Interfaces, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Lucio Isa
- Department of Materials ETH Zurich, Laboratory for Soft Materials and Interfaces, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
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Dietrich K, Jaensson N, Buttinoni I, Volpe G, Isa L. Microscale Marangoni Surfers. Phys Rev Lett 2020; 125:098001. [PMID: 32915612 DOI: 10.1103/physrevlett.125.098001] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
We apply laser light to induce the asymmetric heating of Janus colloids adsorbed at water-oil interfaces and realize active micrometric "Marangoni surfers." The coupling of temperature and surfactant concentration gradients generates Marangoni stresses leading to self-propulsion. Particle velocities span 4 orders of magnitude, from microns/s to cm/s, depending on laser power and surfactant concentration. Experiments are rationalized by finite elements simulations, defining different propulsion regimes relative to the magnitude of the thermal and solutal Marangoni stress components.
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Affiliation(s)
- Kilian Dietrich
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Nick Jaensson
- Laboratory for Soft Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Ivo Buttinoni
- Institut für Experimentelle Kolloidphysik, Heinrich-Heine Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - Giorgio Volpe
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
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40
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Sprenger AR, Fernandez-Rodriguez MA, Alvarez L, Isa L, Wittkowski R, Löwen H. Active Brownian Motion with Orientation-Dependent Motility: Theory and Experiments. Langmuir 2020; 36:7066-7073. [PMID: 31975603 DOI: 10.1021/acs.langmuir.9b03617] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Combining experiments on active colloids, whose propulsion velocity can be controlled via a feedback loop, and the theory of active Brownian motion, we explore the dynamics of an overdamped active particle with a motility that depends explicitly on the particle orientation. In this case, the active particle moves faster when oriented along one direction and slower when oriented along another, leading to anisotropic translational dynamics which is coupled to the particle's rotational diffusion. We propose a basic model of active Brownian motion for orientation-dependent motility. On the basis of this model, we obtain analytical results for the mean trajectories, averaged over the Brownian noise for various initial configurations, and for the mean-square displacements including their non-Gaussian behavior. The theoretical results are found to be in good agreement with the experimental data. Orientation-dependent motility is found to induce significant anisotropy in the particle displacement, mean-square displacement, and non-Gaussian parameter even in the long-time limit. Our findings establish a methodology for engineering complex anisotropic motilities of active Brownian particles, with a potential impact in the study of the swimming behavior of microorganisms subjected to anisotropic driving fields.
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Affiliation(s)
- Alexander R Sprenger
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | | | - Laura Alvarez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
| | - Raphael Wittkowski
- Institut für Theoretische Physik, Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
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Abstract
The confinement of colloidal particles at liquid interfaces offers many opportunities for materials design. Adsorption is driven by a reduction of the total free energy as the contact area between the two liquids is partially replaced by the particle. From an application point of view, particle-stabilized interfaces form emulsions and foams with superior stability. Liquid interfaces also effectively confine colloidal particles in two dimensions and therefore provide ideal model systems to fundamentally study particle interactions, dynamics, and self-assembly. With progress in the synthesis of nanomaterials, more and more complex and functional particles are available for such studies. In this Account, we focus on poly(N-isopropylacrylamide) nanogels and microgels. These are cross-linked polymeric particles that swell and soften by uptaking large amounts of water. The incorporated water can be partially expelled, causing a volume phase transition into a collapsed state when the temperature is increased above approximately 32 °C. Soft microgels adsorbed to liquid interfaces significantly deform under the influence of interfacial tension and assume cross sections exceeding their bulk dimensions. In particular, a pronounced corona forms around the microgel core, consisting of dangling chains at the microgel periphery. These polymer chains expand at the interface and strongly affect the interparticle interactions. The particle deformability therefore leads to a significantly more complex interfacial phase behavior that provides a rich playground to explore structure formation processes. We first discuss the characteristic "fried-egg" or core-corona morphology of individual microgels adsorbed to a liquid interface and comment on the dependence of this interfacial morphology on their physicochemical properties. We introduce different theoretical models to describe their interfacial morphology. In a second part, we introduce how ensembles of microgels interact and self-assemble at liquid interfaces. The core-corona morphology and the possibility to force these elements into overlap upon compression results in a complex phase behavior with a phase transition between microgels with extended and collapsed coronae. We discuss the influence of the internal particle architecture, also including core-shell microgels with rigid cores, on the phase behavior. Finally, we present new routes for the realization of more complex structures, resulting from multiple deposition protocols and from engineering the interaction potential of the individual particles.
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Affiliation(s)
- Marcel Rey
- Institute of Particle Technology (LFG), Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander University Erlangen-Nürnberg, Haberstrasse 9a, 91058 Erlangen, Germany
| | - Miguel Angel Fernandez-Rodriguez
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Matthias Karg
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Nicolas Vogel
- Institute of Particle Technology (LFG), Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander University Erlangen-Nürnberg, Haberstrasse 9a, 91058 Erlangen, Germany
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Bochenek S, Scotti A, Ogieglo W, Fernández-Rodríguez MÁ, Schulte MF, Gumerov RA, Bushuev NV, Potemkin II, Wessling M, Isa L, Richtering W. Effect of the 3D Swelling of Microgels on Their 2D Phase Behavior at the Liquid-Liquid Interface. Langmuir 2019; 35:16780-16792. [PMID: 31782927 DOI: 10.1021/acs.langmuir.9b02498] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigate soft, temperature-sensitive microgels at fluid interfaces. Though having an isotropic, spherical shape in bulk solution, the microgels become anisotropic upon adsorption. The structure of microgels at interfaces is described by a core-corona morphology. Here, we investigate how changing temperature across the microgel volume phase transition temperature, which leads to swelling/deswelling of the microgels in the aqueous phase, affects the phase behavior within the monolayer. We combine compression isotherms, atomic force microscopy imaging, multiwavelength ellipsometry, and computer simulations. At low compression, the interaction between adsorbed microgels is dominated by their highly stretched corona and the phase behavior of the microgel monolayers is the same. The polymer segments within the interface lose their temperature-sensitivity because of the strong adsorption to the interface. At high compression, however, the portions of the microgels that are located in the aqueous side of the interface become relevant and prevail in the microgel interactions. These portions are able to collapse and, consequently, the isostructural phase transition is altered. Thus, the temperature-dependent swelling perpendicular to the interface ("3D") affects the compressibility parallel to the interface ("2D"). Our results highlight the distinctly different behavior of soft, stimuli-sensitive microgels as compared to rigid nanoparticles.
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Affiliation(s)
- Steffen Bochenek
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Andrea Scotti
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Wojciech Ogieglo
- Chemical Process Engineering , RWTH Aachen University , Forckenbeckstrasse 51 , 52064 Aachen , Germany
| | - Miguel Ángel Fernández-Rodríguez
- Laboratory for Soft Materials and Interfaces, Department of Materials , ETH Zurich , Vladimir-Prelog-Weg 1-5/10 , 8093 Zurich , Switzerland
| | - M Friederike Schulte
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Rustam A Gumerov
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Nikita V Bushuev
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
| | - Igor I Potemkin
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
- National Research South Ural State University , Chelyabinsk 454080 , Russian Federation
| | - Matthias Wessling
- Chemical Process Engineering , RWTH Aachen University , Forckenbeckstrasse 51 , 52064 Aachen , Germany
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials , ETH Zurich , Vladimir-Prelog-Weg 1-5/10 , 8093 Zurich , Switzerland
| | - Walter Richtering
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
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Smith KB, Fernandez-Rodriguez MÁ, Isa L, Mezzenga R. Creating gradients of amyloid fibrils from the liquid-liquid interface. Soft Matter 2019; 15:8437-8440. [PMID: 31599318 DOI: 10.1039/c9sm01826c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report a method to deposit amyloid fibrils on a substrate creating gradients in orientation and coverage on demand. For this purpose, we adapt a colloidal self-assembly method at liquid-liquid interfaces to deposit amyloid fibrils on a substrate from the water-hexane interface, while simultaneously compressing it. The amyloid fibril layers orient perpendicularly to the compression, ranging from isotropic to nematic distributions. We furthermore observe reproducible transitions from a monolayer to a bilayer and from a bilayer to multilayers with increasing surface pressures. The creation of each new layer is accompanied by a systematic drop in the structural order of the system, which is however regained upon further compression. This method shows great potential for overcoming the thin-film engineering challenges associated with the manipulation of sticky amyloid fibrils, and allows their ex situ visualisation under compression at the fluid-fluid interface, a situation relevant to understand the propagation of amyloid-related diseases, their functional role in biological systems, and their potential for technological applications.
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Affiliation(s)
- Kathleen Beth Smith
- Department of Health Sciences and Technology, Swiss Federal Institut of Technology Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
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Zanini M, Cingolani A, Hsu CP, Fernández-Rodríguez MÁ, Soligno G, Beltzung A, Caimi S, Mitrano D, Storti G, Isa L. Mechanical phase inversion of Pickering emulsions via metastable wetting of rough colloids. Soft Matter 2019; 15:7888-7900. [PMID: 31532443 DOI: 10.1039/c9sm01352k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The possibility to invert emulsions from oil-in-water to water-in-oil (or vice versa) in a closed system, i.e. without any formulation change, remains an open fundamental challenge with many opportunities for industrial applications. Here, we propose a mechanism that exploits particle surface roughness to induce metastable wetting and obtain mechanically-responsive Pickering emulsions. We postulate that the phase inversion is driven by an in situ switch of the particle wettability from metastable positions at the interface following the input of controlled mechanical energy. Oil-in-water emulsions can be prepared at low energy using mildly hydrophobic rough colloids, which are dispersed in water and weakly pinned at the interface, and switched to water-in-oil emulsions by a second emulsification at higher energy, which triggers the relaxation of the particle contact angle. The same principle is demonstrated for the complementary emulsions using mildly hydrophilic colloids initially dispersed in oil. Our experiments and simulations support that the delicate interplay between particle surface design during synthesis and the energy of the emulsification process can encode a kinetic pathway for the phase inversion. Both organic and inorganic nanoparticles can be used, allowing for the future implementation of our strategy in a broad range of smart industrial formulations.
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Affiliation(s)
- Michele Zanini
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich, Switzerland.
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Roila F, Ruggeri B, Ballatori E, Patoia L, Palazzo S, Colucci G, Di Costanzo F, Cascinu S, Labianca R, Sobrero A, Cortesi E, Bressi C, Ferraldeschi R, Mazzoli M, Evangelista M, Di Fonzo C, Cigolari S, Angelini V, Cioffi A, Guardasole V, Zarra E, Tonato M, Betti M, Marrocolo F, Bon-ciarelli V, Cetto G, Silingardi V, Cognetti F, Beretta G, Pessi A, Mosconi S, Milesi L, Bertetto O, Malacarne P, Marzola M, Margutti G, Modenesi C, Manente P, Comandone A, Oliva C, Berniolo P, Cutin SC, Luporini G, Colucci G, Recaldin E, Nicodemo M, Picece V, Turaz-za M, Ferrazzi E, Solina G, Rosati G, Rossi A, Manzione L, Sozzi P, Fornarini G, Lavarello A, Catalano G, Giordani P, Alessandroni P, Troccoli G, Ramus GV, Tonda L, Sirgiovanni M, Iannello GP, Tinessa V, Ruggiero A, Palazzo S, Barni S, Mandalà M, Cremonesi M, Porcile G, Destefanis M, Testore F, Carteni G, Daniele B, Volta C, Ferraù F, Zaniboni A, Marchetti P, Citone G, Cefaro GA, Iacono C, Musi M, Mozzicafreddo A, Imperiale FN, Filippelli G, Sciacca V, D'Aprile M, Isa L, Recchia F, Spada S, Cascinu S, Carroccio R, Mustacchi G, Ceccherini R, Chetrì M, Rizzo P, Botturi M, Marchei P, Bretti S, Montalbetti L, Reguzzoni G, Massidda B, Ionta M, Cruciani G, Prosperi A, Mantovani G, Sidoti V, Peta A, Greco E, Cicero G, Sobrero A, Marsilio P, Vigevani E, Rimondi G, Gebbia V, Nuzzo A, Biondi E, Caroti C, D'Amico M, Tuveri G, Pieri G, Enrici RM, Tonini G, Santini D, Iannone T, Pizza C, Belli M, Del Prete S, Pizza C, Trevisonne R, Serlenga M, Laricchiuta R, Lacava V, Bumma C, Roselli M, Verderame F, Mascia V, Perrone D, Prantera T, Venuta S, Nastasi G, Bortolussi V, Lembo A. Adjuvant Systemic Therapies in Patients with Colorectal Cancer: An Audit on Clinical Practice in Italy. Tumori 2019; 91:472-6. [PMID: 16457144 DOI: 10.1177/030089160509100605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aims and Background Rarely are conclusions from clinical trials summarized in international consensus conferences and promptly transferred to patient care. The adjuvant therapy for colorectal cancer used in daily clinical practice in Italy is described and compared with the recommendations of the 1990 NIH Consensus Conference. Patients and Methods We audited prescriptions of adjuvant systemic therapies for Italian colorectal cancer patients in 82 centers during a fixed one-week period. Results Among 434 patients receiving adjuvant chemotherapy there were 139 (42.5%) colon cancer patients with N- and 169 (51.7%) with N+ regional nodal involvement. Treatment at academic centers, a young age, T4 and a low total number of lymph nodes removed at surgery were the factors potentially justifying the decision for adjuvant chemotherapy in stage II colon cancer patients. The most common chemotherapy used was a bolus of 5-fluorouracil/folinic acid for 6 months (75.8%). Adjuvant radiotherapy was not administered to 37 (38.5%) of 96 patients with stage II and III rectal cancer. Conclusions The study shows that a substantial proportion of patients on adjuvant treatment at a certain time point in a large enough sample of Italian centers are stage II (potential over-treatment) and that an under-treatment of stage II and III rectal cancer patients (lack of radiotherapy) occurs too often in daily clinical practice in this country.
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Affiliation(s)
| | - Fausto Roila
- Divisione Oncologia Medica, Ospedale Policlinico, Perugia
| | | | - Enzo Ballatori
- Unità di Statistica Medica, Dip. Medicina Interna e Sanità Pubblica, Università, L'Aquila
| | - Lucio Patoia
- Dip. Medicina Interna e Scienze Oncologiche, Università, Perugia
| | | | - Giuseppe Colucci
- Oncologia Medica e Sperimentale, Istituto Nazionale Tumori, Bari
| | | | | | | | | | - E. Cortesi
- D.H. Oncologico Policlinico Umberto I, Roma
| | - C. Bressi
- D.H. Oncologico Policlinico Umberto I, Roma
| | | | - M. Mazzoli
- D.H. Oncologico Policlinico Umberto I, Roma
| | | | | | - S. Cigolari
- III Medicina Interna, Università Federico II, Napoli
| | - V. Angelini
- III Medicina Interna, Università Federico II, Napoli
| | - A. Cioffi
- III Medicina Interna, Università Federico II, Napoli
| | - V. Guardasole
- III Medicina Interna, Università Federico II, Napoli
| | - E. Zarra
- III Medicina Interna, Università Federico II, Napoli
| | - M. Tonato
- Divisione Oncologia Medica, Policlinico, Perugia
| | - M. Betti
- Divisione Oncologia Medica, Policlinico, Perugia
| | - F. Marrocolo
- Divisione Oncologia Medica, Policlinico, Perugia
| | | | - G. Cetto
- Divisione Clinicizzata Oncologia Medica, Ospedale Maggiore, Verona
| | | | - F. Cognetti
- Divisione Oncologia Medica, Istituto Nazionale dei Tumori, Roma
| | - G. Beretta
- Divisione Oncologia Medica, Ospedali Riuniti, Bergamo
| | - A. Pessi
- Divisione Oncologia Medica, Ospedali Riuniti, Bergamo
| | - S. Mosconi
- Divisione Oncologia Medica, Ospedali Riuniti, Bergamo
| | - L. Milesi
- Divisione Oncologia Medica, Ospedali Riuniti, Bergamo
| | - O. Bertetto
- Divisione Oncologia Medica, Ospedale S. Giovanni Molinette, Torino
| | - P. Malacarne
- Divisione Oncologia Clinica, Ospedale S. Anna, Ferrara
| | - M. Marzola
- Divisione Oncologia Clinica, Ospedale S. Anna, Ferrara
| | - G. Margutti
- Divisione Oncologia Clinica, Ospedale S. Anna, Ferrara
| | - C. Modenesi
- Divisione Oncologia Clinica, Ospedale S. Anna, Ferrara
| | - P. Manente
- Divisione Oncologia Medica, Ospedale Civile, Castelfranco Veneto
| | - A. Comandone
- Divisione Oncologia Medica, Ospedale Gradenigo, Torino
| | - C. Oliva
- Divisione Oncologia Medica, Ospedale Gradenigo, Torino
| | - P. Berniolo
- Divisione Oncologia Medica, Ospedale Gradenigo, Torino
| | | | - G. Luporini
- Divisione Oncologia Medica, Ospedale S. Carlo Borromeo, Milano
| | - G. Colucci
- Divisione Oncologia Medica e Sperimentale, Istituto Nazionale Tumori, Bari
| | - E. Recaldin
- Divisione Oncologia Medica, Ospedale S. Cuore, Negrar, Verona
| | - M. Nicodemo
- Divisione Oncologia Medica, Ospedale S. Cuore, Negrar, Verona
| | - V. Picece
- Divisione Oncologia Medica, Ospedale S. Cuore, Negrar, Verona
| | - M. Turaz-za
- Divisione Oncologia Medica, Ospedale S. Cuore, Negrar, Verona
| | - E. Ferrazzi
- Divisione Oncologia Medica, Ospedale Civile, Rovigo
| | - G. Solina
- Divisione Chirurgia Oncologica, Ospedale Cervello, Palermo
| | - G. Rosati
- Divisione Oncologia Medica, Ospedale Civile, Potenza
| | - A. Rossi
- Divisione Oncologia Medica, Ospedale Civile, Potenza
| | - L. Manzione
- Divisione Oncologia Medica, Ospedale Civile, Potenza
| | - P. Sozzi
- Divisione Oncologia Medica, Ospedale degli Infermi, Biella
| | - G. Fornarini
- Divisione Oncologia Medica, Ospedale degli Infermi, Biella
| | - A. Lavarello
- Divisione Oncologia Medica, Ospedale Civile, Sestri Levante
| | - G. Catalano
- Divisione Oncologia Medica, Ospedale S. Salvatore, Pesaro
| | - P. Giordani
- Divisione Oncologia Medica, Ospedale S. Salvatore, Pesaro
| | | | - G. Troccoli
- Divisione Oncologia Medica, Policlinico Universitario, Bari
| | - G. Vietti Ramus
- UO di Oncologia, Ospedale S. Giovanni Bosco, ASL Torino 4, Torino
| | - L. Tonda
- UO di Oncologia, Ospedale S. Giovanni Bosco, ASL Torino 4, Torino
| | - M.P. Sirgiovanni
- UO di Oncologia, Ospedale S. Giovanni Bosco, ASL Torino 4, Torino
| | | | - V. Tinessa
- Divisione Oncologia Medica, Ospedale Civile, Benevento
| | - A Ruggiero
- Divisione Oncologia Medica, Ospedale Civile, Benevento
| | - S. Palazzo
- Divisione Oncologia Medica, Ospedale Mariano Santo, Cosenza
| | - S. Barni
- UO di Oncologia Medica, Azienda Ospedaliera, Treviglio
| | - M. Mandalà
- UO di Oncologia Medica, Azienda Ospedaliera, Treviglio
| | - M. Cremonesi
- UO di Oncologia Medica, Azienda Ospedaliera, Treviglio
| | - G. Porcile
- Divisione Oncologia Medica, Ospedale Civile, Alba
| | | | - F. Testore
- Divisione Oncologia Medica, Ospedale Civile, Asti
| | - G. Carteni
- Divisione Oncologia Medica, Ospedale Cardarelli, Napoli
| | - B. Daniele
- Divisione Oncologia Medica, Istituto Nazionale Tumori, Napoli
| | - C. Volta
- Divisione Oncologia Medica, Ospedale Maggiore della Carità, Novara
| | - F. Ferraù
- Divisione Oncologia Medica, Ospedale Civile, Taormina
| | - A. Zaniboni
- Divisione Oncologia Medica, C. Cura Poliambulanza, Brescia
| | - P. Marchetti
- Divisione Oncologia Medica, Ospedale S. Salvatore, L'Aquila
| | - G. Citone
- Divisione Oncologia Medica, Ospedale S. Salvatore, L'Aquila
| | | | - C. Iacono
- Divisione Oncologia Medica, Ospedale Civile, Ragusa
| | - M. Musi
- Divisione Oncologia Medica, Ospedale Generale, Aosta
| | | | | | | | - V. Sciacca
- Divisione Oncologia Medica, Ospedale S. Maria Goretti, Latina
| | - M. D'Aprile
- Divisione Oncologia Medica, Ospedale S. Maria Goretti, Latina
| | - L. Isa
- Divisione Oncologia Medica, Ospedale Civile, Gorgonzola
| | - F. Recchia
- Divisione Oncologia Medica, Ospedale Civile, Avezzano
| | - S. Spada
- D.H. Oncologico, Ospedale Umberto I, Siracusa
| | - S. Cascinu
- Divisione Oncologia Medica, Ospedale Civile, Parma
| | - R. Carroccio
- Unità Operativa Complessa di Oncologia Medica, Ospedale Umberto I, Enna
| | | | | | - M. Chetrì
- D.H. Oncologico, Ospedale di Summa, Brindisi
| | - P. Rizzo
- D.H. Oncologico, Ospedale di Summa, Brindisi
| | - M. Botturi
- UO Radioterapia, Ospedale Niguarda, Milano
| | - P. Marchei
- Divisione Oncologia Medica, Università La Sapienza, Roma
| | - S. Bretti
- Divisione Oncologia Medica, Ospedale Civile, Ivrea
| | | | - G. Reguzzoni
- D. H. Oncologico, Ospedale Civile, Busto Arsizio
| | - B. Massidda
- Oncologia Medica, Policlinico Universitario, Monserrato, Cagliari
| | - M.T. Ionta
- Oncologia Medica, Policlinico Universitario, Monserrato, Cagliari
| | - G. Cruciani
- Divisione Oncologia Medica, Ospedale Civile, Lugo
| | | | - G. Mantovani
- Divisione Oncologia Medica, Università, Cagliari
| | - V. Sidoti
- Divisione Oncologia Medica, Ospedale Civile, Pinerolo
| | - A. Peta
- Divisione Ematologia Oncologica, Ospedale Pugliese, Catanzaro
| | - E. Greco
- Divisione Oncologia Medica, Ospedale Civile, Lamezia Terme
| | - G. Cicero
- Divisione Oncologia Medica, Ospedale Civile, Castrovillari
| | - A. Sobrero
- Divisione Oncologia Medica, Policlinico Universitario, Udine
| | - P. Marsilio
- Divisione Oncologia Medica, Ospedale Civile, Udine
| | - E. Vigevani
- Divisione Oncologia Medica, Ospedale Civile, Tolmezzo
| | - G. Rimondi
- Divisione Oncologia Medica, Ospedale Civile, Tolmezzo
| | - V. Gebbia
- Divisione Oncologia Medica, Policlinico Universitario, Palermo
| | - A. Nuzzo
- UO di Oncologia Medica, Ospedale Renzetti, Lanciano
| | - E. Biondi
- UO di Oncologia Medica, Ospedale Renzetti, Lanciano
| | - C. Caroti
- Divisione Oncologia Medica, Ospedale Galliera, Genova
| | - M. D'Amico
- Divisione Oncologia Medica, Ospedale Galliera, Genova
| | - G. Tuveri
- Divisione Oncologia Medica, Ospedale della Pietà, Trieste
| | - G. Pieri
- Divisione Oncologia Medica, Ospedale della Pietà, Trieste
| | | | - G. Tonini
- Oncologia Medica, Università Campus Biomedico, Roma
| | - D. Santini
- Oncologia Medica, Università Campus Biomedico, Roma
| | - T. Iannone
- Unità di Radioterapia Oncologica, Ospedale civile, Belluno
| | - C. Pizza
- Divisione Oncologia Medica, Ospedale S. Maria della Pietà, Nola
| | | | - S. Del Prete
- Divisione Oncologia Medica, Ospedale Civile, Frattamaggiore
| | - C. Pizza
- Divisione Oncologia Medica, Ospedale S. Maria della Pietà, Nola
| | - R. Trevisonne
- Divisione Oncologia Medica e Radioterapia, Ospedale Civile, Ascoli Piceno
| | - M. Serlenga
- Oncologia Radioterapica, Ospedale Civile, Barletta
| | | | - V. Lacava
- D.H. Oncologia, Università La Sapienza, Roma
| | - C. Bumma
- Divisione Oncologia Medica, Ospedale S. Giovanni Vecchio, Torino
| | - M. Roselli
- Oncologia Medica, Università di Roma “Tor Vergata”, Roma
| | | | - V. Mascia
- Divisione Oncologia Medica, Policlinico Universitario, Cagliari
| | - D. Perrone
- Divisione Oncologia Medica, Ospedale Civile, Saluzzo, Cuneo
| | - T. Prantera
- Divisione Oncologia Medica, Ospedale S. Giovanni di Dio, Crotone
| | - S. Venuta
- Divisione Oncologia Medica, Policlinico Universitario, Catanzaro
| | - G. Nastasi
- Divisione Medicina Oncologica, Ospedale Civile, Alzano Lombardo
| | | | - A. Lembo
- Servizio Oncologia Medica, Casa di Cura M. Polo, Roma
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Schroyen B, Hsu CP, Isa L, Van Puyvelde P, Vermant J. Stress Contributions in Colloidal Suspensions: The Smooth, the Rough, and the Hairy. Phys Rev Lett 2019; 122:218001. [PMID: 31283345 DOI: 10.1103/physrevlett.122.218001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/18/2019] [Indexed: 06/09/2023]
Abstract
The collective properties of colloidal suspensions, including their rheology, reflect an interplay between colloidal and hydrodynamic forces. The surface characteristics of the particles play a crucial role, in particular, for applications in which interparticle distances become small, i.e., at high concentrations or in aggregates. In this Letter, we directly investigate this interplay via the linear viscoelastic response of the suspensions in the high-frequency regime, using particles with controlled surface topographies, ranging from smooth to hairy and rough particles. We focus directly on the stresses at the particle level and reveal a strong impact of the surface topography on the short-range interactions, both dissipative and elastic. As the particle topography becomes more complex, the local stresses depend on how the topography is generated. The findings in this Letter, in particular, show how changes in topography can both screen or enhance the dissipation, which can be used to engineer the properties of dense or aggregated suspensions.
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Affiliation(s)
- Bram Schroyen
- Department of Materials, ETH Zürich, 8032 Zürich, Switzerland
| | - Chiao-Peng Hsu
- Department of Materials, ETH Zürich, 8032 Zürich, Switzerland
| | - Lucio Isa
- Department of Materials, ETH Zürich, 8032 Zürich, Switzerland
| | | | - Jan Vermant
- Department of Materials, ETH Zürich, 8032 Zürich, Switzerland
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47
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Camerin F, Fernández-Rodríguez MÁ, Rovigatti L, Antonopoulou MN, Gnan N, Ninarello A, Isa L, Zaccarelli E. Microgels Adsorbed at Liquid-Liquid Interfaces: A Joint Numerical and Experimental Study. ACS Nano 2019; 13:4548-4559. [PMID: 30865829 DOI: 10.1021/acsnano.9b00390] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Soft particles display highly versatile properties with respect to hard colloids and even more so at fluid-fluid interfaces. In particular, microgels, consisting of a cross-linked polymer network, are able to deform and flatten upon adsorption at the interface due to the balance between surface tension and internal elasticity. Despite the existence of experimental results, a detailed theoretical understanding of this phenomenon is still lacking due to the absence of appropriate microscopic models. In this work, we propose an advanced modeling of microgels at a flat water/oil interface. The model builds on a realistic description of the internal polymeric architecture and single-particle properties of the microgel and is able to reproduce its experimentally observed shape at the interface. Complementing molecular dynamics simulations with in situ cryo-electron microscopy experiments and atomic force microscopy imaging after Langmuir-Blodgett deposition, we compare the morphology of the microgels for different values of the cross-linking ratios. Our model allows for a systematic microscopic investigation of soft particles at fluid interfaces, which is essential to develop predictive power for the use of microgels in a broad range of applications, including the stabilization of smart emulsions and the versatile patterning of surfaces.
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Affiliation(s)
- Fabrizio Camerin
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Basic and Applied Sciences for Engineering , Sapienza University of Rome , Via Antonio Scarpa 14 , 00161 Roma , Italy
| | - Miguel Ángel Fernández-Rodríguez
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Lorenzo Rovigatti
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Maria-Nefeli Antonopoulou
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Nicoletta Gnan
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Andrea Ninarello
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Lucio Isa
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Emanuela Zaccarelli
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
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48
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James NM, Hsu CP, Spencer ND, Jaeger HM, Isa L. Tuning Interparticle Hydrogen Bonding in Shear-Jamming Suspensions: Kinetic Effects and Consequences for Tribology and Rheology. J Phys Chem Lett 2019; 10:1663-1668. [PMID: 30896954 DOI: 10.1021/acs.jpclett.9b00135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The reversible shear-induced solidification of dense suspensions, known as shear jamming, critically depends on frictional interparticle contacts. Recently, it was shown that shear jamming can be strongly affected by molecular-scale interactions between particles, e.g., by chemically controlling their propensity for hydrogen bonding. However, hydrogen bonding not only enhances interparticle friction but also introduces (reversible) adhesion, whose interplay with friction in shear-jamming systems has so far remained unclear. Here, we present atomic force microscopy studies to assess interparticle adhesion, its relationship to friction, and how these attributes are influenced by urea, a molecule that interferes with hydrogen bonding. We characterize the kinetics of this process with nuclear magnetic resonance, relating it to the time dependence of the macroscopic flow behavior with rheological measurements. We find that time-dependent urea sorption reduces friction and adhesion, causing a reduction in the high-shear viscosity. These results extend our mechanistic understanding of chemical effects on the nature of shear jamming, promising new avenues for fundamental studies and applications alike.
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Affiliation(s)
- Nicole M James
- James Franck Institute , The University of Chicago , Chicago , Illinois 60637 , United States
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Chiao-Peng Hsu
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zurich , 8093 Zurich , Switzerland
- Laboratory for Surface Science and Technology, Department of Materials , ETH Zurich , 8093 Zurich , Switzerland
| | - Nicholas D Spencer
- Laboratory for Surface Science and Technology, Department of Materials , ETH Zurich , 8093 Zurich , Switzerland
| | - Heinrich M Jaeger
- James Franck Institute , The University of Chicago , Chicago , Illinois 60637 , United States
- Department of Physics , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Lucio Isa
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zurich , 8093 Zurich , Switzerland
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49
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Aloi A, Vilanova N, Isa L, de Jong AM, Voets IK. Super-resolution microscopy on single particles at fluid interfaces reveals their wetting properties and interfacial deformations. Nanoscale 2019; 11:6654-6661. [PMID: 30896703 DOI: 10.1039/c8nr08633h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Solid particles adsorbed at fluid interfaces are crucial for the mechanical stability of Pickering emulsions. The key parameter which determines the kinetic and thermodynamic properties of these colloids is the particle contact angle, θ. Several methods have recently been developed to measure the contact angle of individual particles adsorbed at liquid-liquid interfaces, as morphological and chemical heterogeneities at the particle surface can significantly affect θ. However, none of these techniques enables the simultaneous visualization of the nanoparticles and the reconstruction of the fluid interface to which they are adsorbed, in situ. To tackle this challenge, we utilize a newly developed super-resolution microscopy method, called iPAINT, which exploits non-covalent and continuous labelling of interfaces with photo-activatable fluorescent probes. Herewith, we resolve with nanometer accuracy both the position of individual nanoparticles at a water-octanol interface and the location of the interface itself. First, we determine single particle contact angles for both hydrophobic and hydrophilic spherical colloids. These experiments reveal a non-negligible dependence of θ on particle size, from which we infer an effective line tension, τ. Next, we image elliptical particles at a water-decane interface, showing that the corresponding interfacial deformations can be clearly captured by iPAINT microscopy.
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Affiliation(s)
- A Aloi
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands. and Laboratory of Self-Organizing Soft Matter, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands and Laboratory of Macromolecular and Organic Chemistry, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands
| | - N Vilanova
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands. and Laboratory of Macromolecular and Organic Chemistry, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands
| | - L Isa
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials, ETH Zurich, Vladimir-Prelog Weg 5, 8093 Zürich, Switzerland
| | - A M de Jong
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands. and Laboratory of Molecular Biosensing, Department of Applied Physics, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands
| | - I K Voets
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands. and Laboratory of Self-Organizing Soft Matter, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands and Laboratory of Macromolecular and Organic Chemistry, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands and Laboratory of Physical Chemistry, Department of Chemistry and Chemical Engineering, Eindhoven University of Technology, Post Office Box 513, 5600 MB Eindhoven, The Netherlands
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50
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Mathis CH, Simič R, Kang C, Ramakrishna SN, Isa L, Spencer ND. Indenting polymer brushes of varying grafting density in a viscous fluid: A gradient approach to understanding fluid confinement. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.02.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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