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Fesenmeier DJ, Kim S, Won YY. Effect of temperature on the air-water surface mechanical behavior of water-spread block copolymer micelles. SOFT MATTER 2023; 19:9269-9281. [PMID: 38009013 PMCID: PMC10782589 DOI: 10.1039/d3sm01003a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
In the pursuit of the development of a first-in-kind polymer lung surfactant (PLS) therapeutic whose effects are biophysical in nature, a comprehensive understanding of the factors affecting the air-water surface mechanical behavior of water-spread block copolymer micelles is desired. To this end, we explore the effect of temperature on the surface mechanical behavior of two different micelle core chemistries, poly(styrene) (PS) and poly(tert-butyl methacrylate) (PtBMA), each having poly(ethylene glycol) (PEG) as the hydrophilic block. The behavior is characterized using surface pressure-area isotherms and quantitative Brewster angle microscopy. The results indicate that the temperature has a significant effect on the micelle structure at the interface and this effect is related to the core Tg as well as the core interfacial tension properties. When temperature is higher than the core Tg for PS-PEG, the spherical micelle core rearranges to form an oblate-like structure which increases its interfacial area. The structural rearrangement changes the mechanism by which the film produces high surface pressure. For PtBMA-PEG, which has a lower interfacial tension with water and air compared to PS, the core domains spread at the interface when the mobility is sufficiently high such that a PtBMA film is formed under high compression. The implications of these changes on PLS efficacy are discussed highlighting the importance of core Tg characterization for polymer nanoparticle applications.
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Affiliation(s)
- Daniel J Fesenmeier
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.
| | - Seyoung Kim
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.
- Department of Polymer Science and Engineering, Dankook University, Yongin, Gyeonggi 16890, Republic of Korea
| | - You-Yeon Won
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.
- Purdue University Institute for Cancer Research, West Lafayette, IN 47907, USA
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2
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Socas LBP, Ambroggio EE. Linking surface tension to water polarization with a new hypothesis: The Ling-Damodaran Isotherm. Colloids Surf B Biointerfaces 2023; 230:113515. [PMID: 37634284 DOI: 10.1016/j.colsurfb.2023.113515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023]
Abstract
Studying aqueous solutions of complex (bio)polymers is essential from both theoretical and practical perspectives. To understand the principles that govern the properties of these solutions is pivotal for the study of biological processes, considering that the most distinguished components of the cells are polymers (proteins, nucleic acids). These macromolecular aqueous systems, known as colloids, has raise the interest of scientists in recent years. It is known that several physicochemical properties deviate from ideal behaviour in this kind of solutions and that the physical state of water is different compared to its pure state. Particularly, the surface tension of such mixtures often shows a peculiar profile at semi-dilute and concentrated conditions. Here, we joined the colloidal concept of water polarization (proposed in the Association-Induction Hypothesis) with Damodaran's formalism for surface tension to theoretically derive a compelling mathematical model that explains the behaviour of polymer solutions. We measured the surface tension and osmolarity of different polyethylene oxide solutions and we used the ACDAN fluorescence probe to assess the water dipolar relaxation (polarization) in these mixtures. As a proof of concept, we also studied the influence of these polymer solutions on lipid interfaces. Our isotherm model explains the experimental observations with a unifying view that correlates with other measured properties, such as osmolarity and water dipolar relaxation. This provides a link between interfacial and bulk physicochemical properties of polymer solutions, also giving a new framework for studying the interaction of colloidal systems with lipid membranes interfaces.
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Affiliation(s)
- L B P Socas
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica-Ranwel Caputto, Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina; CONICET, Universidad Nacional de Córdoba, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina.
| | - E E Ambroggio
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica-Ranwel Caputto, Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina; CONICET, Universidad Nacional de Córdoba, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina.
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3
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Kim S, Park S, Fesenmeier DJ, Jun T, Sarkar K, Won YY. Surface Pressure-Area Mechanics of Water-Spread Poly(ethylene glycol)-Based Block Copolymer Micelle Monolayers at the Air-Water Interface: Effect of Hydrophobic Block Chemistry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:13546-13559. [PMID: 37706471 DOI: 10.1021/acs.langmuir.3c01574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Amphiphilic block copolymer micelles can mimic the ability of natural lung surfactant to reduce the air-water interfacial tension close to zero and prevent the Laplace pressure-induced alveolar collapse. In this work, we investigated the air-water interfacial behaviors of polymer micelles derived from eight different poly(ethylene glycol) (PEG)-based block copolymers having different hydrophobic block chemistries to elucidate the effect of the core block chemistry on the surface mechanics of the block copolymer micelles. Aqueous micelles of about 30 nm in hydrodynamic diameter were prepared from the PEG-based block copolymers via equilibration-nanoprecipitation (ENP) and spread on the water surface using water as the spreading medium. Surface pressure-area isotherm and quantitative Brewster angle microscopy (QBAM) measurements were performed to investigate how the micelle/monolayer structures change during lateral compression of the monolayer; widely varying structural behaviors were observed, including the wrinkling/collapse of micelle monolayers and deformation and/or the desorption of individual micelles. By bivariate correlation regression analysis of surface pressure-area isotherm data, it was found that the rigidity and hydrophobicity of the hydrophobic core domain, which are quantified by glass-transition temperature (Tg) and water contact angle (θ) measurements, respectively, are coupled factors that need to be taken into account concurrently in order to control the surface mechanical properties of polymer micelle monolayers; micelles having rigid and strongly hydrophobic cores exhibited high surface pressure and a high compressibility modulus under high compression. High surface pressure and a high compressibility modulus were also found to be correlated with the formation of wrinkles in the micelle monolayer (visualized by Brewster angle microscopy (BAM)). From this study, we conclude that polymer micelles based on hydrophobic block materials having higher Tg and θ are more suitable for surfactant replacement therapy applications that require the therapeutic surfactant to produce a high surface pressure and modulus at the alveolar air-water interface.
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Affiliation(s)
- Seyoung Kim
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Polymer Science and Engineering, Dankook University, Yongin, Gyeonggi 16890, Republic of Korea
| | - Sungwan Park
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Daniel J Fesenmeier
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Taesuk Jun
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kaustabh Sarkar
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - You-Yeon Won
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue University Institute for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
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4
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Khechine E, Noack S, Schlaad H, Xu J, Reiter G, Reiter R. Reversible Dehydration-Hydration of Poly(ethylene glycol) in Langmuir Monolayers of a Diblock Copolymer Inferred from Changes in Filament Curvature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2710-2718. [PMID: 36757479 DOI: 10.1021/acs.langmuir.2c03179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We investigated changes in the hydration state of poly(ethylene glycol) (PEG) through morphological changes in Langmuir monolayers of a PEG-poly(l-lactide) (PlLA) (PEG-b-PlLA) diblock copolymer. When the PEG blocks were hydrated, we observed a remarkable morphology of bundles of ring-like filaments, arranged concentrically, yielding densely packed disk-like objects with a hollow center. We attribute the uniform curvature of these filaments to a strong mismatch between the molecular volumes occupied by PlLA blocks and hydrated PEG blocks. Under the constraint that each hydrated PEG block is attached to a hydrophobic PlLA block anchored to the air-water interface, this mismatch of molecular volumes caused strong repulsion within the PEG layer, in particular when the PlLA blocks packed tightly. Induced by a transition in the ordering of the PlLA blocks, the PEG blocks lost their hydration shell and packed into a dense polymer brush, accompanied by a reduction of the pressure within the PEG layer. During this packing process, the curvature of the filaments was eliminated and the ring-like filaments fractured into small linear pieces. Upon compression, the linear pieces coalesced and formed long filaments aligned in parallel. Importantly, upon expansion of the Langmuir film, these changes in morphology were reversible, and the PEG blocks could be rehydrated and bundles of concentrically arranged ring-like filaments were reformed. We conclude that the change in curvature of the filaments provides a means for distinguishing between the hydrated and dehydrated states of PEG.
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Affiliation(s)
- Emna Khechine
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
| | - Sebastian Noack
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Street 24-25, 14476 Potsdam, Germany
| | - Helmut Schlaad
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Street 24-25, 14476 Potsdam, Germany
| | - Jun Xu
- Advanced Materials Laboratory of Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Günter Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
| | - Renate Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder Street 3, 79104 Freiburg, Germany
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Guyot M, Daurat C, Vuillet-A-Ciles V, Pontille L, Le Porcher B, Chiriac R, Toche F, Chassagneux F, Toury B, Bois L. Foam Silica Films Synthesized by Calcium Chloride-Assisted Emulsification. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:4540-4549. [PMID: 33830769 DOI: 10.1021/acs.langmuir.1c00083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The development of porous films with an accessible high specific surface area is important for designing new adsorbents, sensors, or catalyst supports. Here, we describe a simple method to prepare a silica foam coating using a calcium chloride-assisted evaporation-induced emulsification method. An alcoholic silica sol containing calcium chloride and a poly(ethylene oxide)-based polymer is deposited on a substrate by dipping. The evaporation of the alcohol induces a phase separation between the silica-rich phase and the calcium-rich one. The size of the droplets increases via a coalescence process until the gelation of the sol, which determines the final pore size between 100 nm and 3 μm. Thermal analysis and monitoring of droplet evaporation confirm that the departure of the solvent is delayed by the presence of calcium chloride in the sol. The influence of the nature of the polymer on the porosity is discussed. The use of a block copolymer such as the Pluronic F-127, which strongly stabilizes the emulsion, allows to reach a low pore size (400 nm), while on the contrary, we propose to use a short poly(ethylene glycol) (PEG) such as PEG-400, which weakly stabilizes it, leading to larger pores (2-3 μm). Furthermore, we show that the addition of a zirconium salt (ZrOCl2·8H2O) to the silica sol accelerates the condensation step of the silica and leads to the decrease in the pore size.
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Affiliation(s)
- Mélanie Guyot
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Céline Daurat
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Victor Vuillet-A-Ciles
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Laurie Pontille
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Bastien Le Porcher
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Rodica Chiriac
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - François Toche
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Fernand Chassagneux
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Bérangère Toury
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
| | - Laurence Bois
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire des Multimatériaux et Interfaces, F-69622 Villeurbanne, France
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6
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Lee J, Pan J, Chun J, Won YY. Unexpected conformational behavior of poly(poly(ethylene glycol) methacrylate)-poly(propylene carbonate)-poly(poly(ethylene glycol) methacrylate) (PPEGMA-PPC-PPEGMA) amphiphilic block copolymers in micellar solution and at the air-water interface. J Colloid Interface Sci 2020; 566:304-315. [PMID: 32007741 DOI: 10.1016/j.jcis.2020.01.080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/03/2020] [Accepted: 01/03/2020] [Indexed: 11/30/2022]
Abstract
HYPOTHESIS This paper investigates the self-assembly behavior of a new amphiphilic block copolymer, PPEGMA-PPC-PPEGMA, in dilute aqueous solution and at the air-water interface. In PPEGMA-PPC-PPEGMA, the hydrophilic PEG moieties exist as side chains attached to the PMA backbone. Because of this unique non-linear architecture, the morphological and conformational properties of self-assembled PPEGMA-PPC-PPEGMA polymers are expected to be different from those of conventional linear PEG-based polymer surfactants. EXPERIMENTS For this study, three PPEGMA-PPC-PPEGMA samples having an identical PPC molecular weight (5.6 kDa) and different PPEGMA molecular weights (7.2, 2.8 and 2.1 kDa on either side) (named "G7C6G7", "G3C5G3", and "G2C6G2", respectively) were synthesized. The micellar self-assembly behaviors of these materials were investigated by cryo-TEM, rheology, DLS, and visual observation. Langmuir monolayers of these materials were characterized by surface mechanical testing. FINDINGS PPEGMA-PPC-PPEGMA micelles were found to have a spherical geometry, irrespective of copolymer composition. Interestingly, G2C6G2 and G3C6G3 micelles formed weakly-bound clusters, whereas G7C6G7 micelles predominantly existed as isolated micelles. Detailed analysis suggests that this unexpected trend in micelle morphology originates from the fact that the PPEGMA blocks are only partially hydrated at aqueous interfaces. Detailed features of the surface pressure-area isotherms obtained from Langmuir PPEG-PPC-PPEGMA monolayers further supported this notion.
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Affiliation(s)
- Jaewon Lee
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Jingyi Pan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Jaehun Chun
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - You-Yeon Won
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA.
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7
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Bhande RS, Mohite LV, Juvekar VA. Langmuir Film of Poly(ethylene oxide) at Air–Water Interface Using Water as Solvent. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b04805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ramesh S. Bhande
- Department of Chemical Engineering, Thadomal Sahani Engineering College, Bandra, Mumbai PIN 400 050, India
| | - Lalaso V. Mohite
- Aditya Birla Science and Technology Company Private Limited, Navi Mumbai, Maharashtra PIN 410208, India
| | - Vinay A. Juvekar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai PIN 400 076, India
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8
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Hong SH, Larocque K, Jaunky DB, Piekny A, Oh JK. Dual disassembly and biological evaluation of enzyme/oxidation-responsive polyester-based nanoparticulates for tumor-targeting delivery. Colloids Surf B Biointerfaces 2018; 172:608-617. [DOI: 10.1016/j.colsurfb.2018.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/27/2018] [Accepted: 09/05/2018] [Indexed: 01/09/2023]
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9
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Application of Depletion Attraction in Mineral Flotation: II. Effects of Depletant Concentration. MINERALS 2018. [DOI: 10.3390/min8100450] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Along with the accompanying theory article, we experimentally investigate the effect of the depletion attraction force on the flotation of malachite. While varying the concentration of the depletion agent (polyethylene glycol), three different systems are studied: pure malachite, pure silica and a 1:1 mass ratio of malachite and silica binary system. We find that the recovery increases significantly as the concentration of the depletion reagents increases for all three systems. However, the recovery suddenly decreases in a certain concentration range, which corresponds to the onset of the decreased surface tension when high concentrations of the depletion agent are used. The decreased surface tension of the air/water interface suggests that the recovery rate is lowered due to the adsorption of the depletion agent to the bubble surface, acting as a polymer brush. We also perform experiments in the presence of a small amount of a collector, sodium oleate. An extremely small amount of the collector (10−10–10−5 M) leads to the increase in the overall recovery, which eventually reaches nearly 100 percent. Nevertheless, the grade worsens as the depletant provides the force to silica particles as well as target malachite particles.
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10
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Kim HC, Arick DQ, Won YY. Air-Water Interfacial Properties of Chloroform-Spread versus Water-Spread Poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG) Polymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4874-4887. [PMID: 29602280 DOI: 10.1021/acs.langmuir.8b00566] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Polymers at fluid interfaces are used for a number of applications that include coatings, electronics, separation, energy, cosmetics, and medicines. Here, we present a study on an amphiphilic block copolymer, poly((d,l-lactic acid- co-glycolic acid)- block-ethylene glycol) (PLGA-PEG), at the air-water interface. PLGA-PEG at the air-water interface prepared by using an organic spreading solvent exhibits an extremely high surface pressure without the occurrence of desorption, making it an attractive candidate for a variety of uses in the areas mentioned above. The origin of this high surface pressure increase was shown to be due to the glass transition of the PLGA segments. The temperature at which this glass transition occurs for the PLGA segments of PLGA-PEG at the air-water interface was measured to be about 290 K by thermodynamic analysis based on the two-dimensional Maxwell relations. However, from an applications standpoint, spreading by an organic solvent greatly limits its scope of feasible uses. To explore the possibility of maintaining the excellent surface mechanical properties of the PLGA-PEG at the air-water interface while not using an organic solvent, we investigated the air-water interfacial properties of water-spread PLGA-PEG. When spread with water, it was shown that the initial micelles that form in the aqueous spreading solution remain intact even after being spread onto the air-water interface. Due to this different morphology, the surface pressure and monolayer stability were greatly reduced for the water-spread PLGA-PEG at the air-water interface. We used the Daoud and Cotton's blob scaling model to describe the desorption process of the water-spread PLGA-PEG at the air-water interface. From the scaling concept, it was shown that with higher PEG molecular weight and larger micelle size, the adsorption energy of the water-spread PLGA-PEG to the air-water interface was increased.
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Affiliation(s)
- Hyun Chang Kim
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Davis Q Arick
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
| | - You-Yeon Won
- School of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
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11
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Agrawal G, Agrawal R. Stimuli-Responsive Microgels and Microgel-Based Systems: Advances in the Exploitation of Microgel Colloidal Properties and Their Interfacial Activity. Polymers (Basel) 2018; 10:E418. [PMID: 30966453 PMCID: PMC6415239 DOI: 10.3390/polym10040418] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/03/2018] [Accepted: 04/03/2018] [Indexed: 11/22/2022] Open
Abstract
In this paper, recent developments in the chemical design of functional microgels are summarized. A wide range of available synthetic methods allows the incorporation of various reactive groups, charges, or biological markers inside the microgel network, thus controlling the deformation and swelling degree of the resulting smart microgels. These microgels can respond to various stimuli, such as temperature, pH, light, electric field, etc. and can show unique deformation behavior at the interface. Due to their switchability and interfacial properties, these smart microgels are being extensively explored for various applications, such as antifouling coatings, cell encapsulation, catalysis, controlled drug delivery, and tissue engineering.
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Affiliation(s)
- Garima Agrawal
- Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Saharanpur Campus, Paper Mill Road, Saharanpur 247001, Uttar Pradesh, India.
| | - Rahul Agrawal
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1500, USA.
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12
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Altering the coffee-ring effect by adding a surfactant-like viscous polymer solution. Sci Rep 2017; 7:500. [PMID: 28356553 PMCID: PMC5428518 DOI: 10.1038/s41598-017-00497-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 03/02/2017] [Indexed: 11/19/2022] Open
Abstract
A uniform deposition of the suspended particles in an evaporating droplet is necessary in many research fields. Such deposition is difficult to achieve, because the coffee-ring effect dominates the internal flow in a droplet. The present study adopts a biocompatible, surfactant-like polymer (Polyethylene glycol, PEG) to break the coffee-ring effect and obtain a relatively uniform deposition of the microparticles with yielding multi-ring pattern over a droplet area. Movements of the suspended particles in evaporating droplets and deposition patterns of them on a glass substrate were analyzed with microscopic images and video files. The PEG in the droplets successfully altered the coffee-ring effect because of the surface tension variation, which induced a centripetal Marangoni flow. Balancing these two phenomena apparently generated the Marangoni vortex. For PEG solution droplets, the pinning–depinning process during evaporation was periodically repeated and multiple rings were regularly formed. In conclusion, adding a surfactant-like viscous polymer in a droplet could provide a uniform coating of suspended particles, such as cells and various biomaterials, which would be essentially required for droplet assays of biomedical applications.
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13
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Abstract
Microgels are macromolecular networks swollen by the solvent in which they are dissolved. They are unique systems that are distinctly different from common colloids, such as, e.g., rigid nanoparticles, flexible macromolecules, micelles, or vesicles. The size of the microgel networks is in the range of several micrometers down to nanometers (then sometimes called "nanogels"). In a collapsed state, they might resemble hard colloids but they can still contain significant amounts of solvent. When swollen, they are soft and have a fuzzy surface with dangling chains. The presence of cross-links provides structural integrity, in contrast to linear and (hyper)branched polymers. Obviously, the cross-linker content will allow control of whether microgels behave more "colloidal" or "macromolecular". The combination of being soft and porous while still having a stable structure through the cross-linked network allows for designing microgels that have the same total chemical composition, but different properties due to a different architecture. Microgels based, e.g., on two monomers but have either statistical spatial distribution, or a core-shell or hollow-two-shell morphology will display very different properties. Microgels provide the possibility to introduce chemical functionality at different positions. Combining architectural diversity and compartmentalization of reactive groups enables thus short-range coexistence of otherwise instable combinations of chemical reactivity. The open microgel structure is beneficial for uptake-release purposes of active substances. In addition, the openness allows site-selective integration of active functionalities like reactive groups, charges, or markers by postmodification processes. The unique ability of microgels to retain their colloidal stability and swelling degree both in water and in many organic solvents allows use of different chemistries for the modification of microgel structure. The capability of microgels to adjust both their shape and volume in response to external stimuli (e.g., temperature, ionic strength and composition, pH, electrochemical stimulus, pressure, light) provides the opportunity to reversibly tune their physicochemical properties. From a physics point of view, microgels are particularly intriguing and challenging, since their intraparticle properties are intimately linked to their interparticle behavior. Microgels, which reveal interface activity without necessarily being amphiphilic, develop even more complex behavior when located at fluid or solid interfaces: the sensitivity of microgels to various stimuli allows, e.g., the modulation of emulsion stability, adhesion, sensing, and filtration. Hence, we envision an ever-increasing relevance of microgels in these fields including biomedicine and process technology. In sum, microgels unite properties of very different classes of materials. Microgels can be based on very different (bio)macromolecules such as, e.g., polysaccharides, peptides, or DNA, as well as on synthetic polymers. This Account focuses on synthetic microgels (mainly based on acrylamides); however, the general, fundamental features of microgels are independent of the chemical nature of the building moieties. Microgels allow combining features of chemical functionality, structural integrity, macromolecular architecture, adaptivity, permeability, and deformability in a unique way to include the "best" of the colloidal, polymeric, and surfactant worlds. This will open the door for novel applications in very different fields such as, e.g., in sensors, catalysis, and separation technology.
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Affiliation(s)
- Felix A. Plamper
- Institute
of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
| | - Walter Richtering
- Institute
of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany
- DWI-Leibniz-Institute for Interactive Materials, 52074 Aachen, Germany
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14
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Huang YR, Lamson M, Matyjaszewski K, Tilton RD. Enhanced interfacial activity of multi-arm poly(ethylene oxide) star polymers relative to linear poly(ethylene oxide) at fluid interfaces. Phys Chem Chem Phys 2017; 19:23854-23868. [DOI: 10.1039/c7cp02841e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interfacial tension reduction, dynamic dilatational elasticity and extent of adsorption were investigated for linear poly(ethylene oxide) (PEO) chains of varying molecular weight and for PEO star polymers with an average of 64 arms per star at air/water, xylene/water, and cyclohexane/water interfaces.
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Affiliation(s)
- Yun-Ru Huang
- Center for Complex Fluids Engineering
- Department of Chemical Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Melissa Lamson
- Center for Complex Fluids Engineering
- Department of Chemistry
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Krzysztof Matyjaszewski
- Center for Complex Fluids Engineering
- Department of Chemistry
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Robert D. Tilton
- Center for Complex Fluids Engineering
- Department of Chemical Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
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15
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Broumand A, Emam-Djomeh Z, Khodaiyan F, Mirzakhanlouei S, Davoodi D, Moosavi-Movahedi AA. Nano-web structures constructed with a cellulose acetate/lithium chloride/polyethylene oxide hybrid: Modeling, fabrication and characterization. Carbohydr Polym 2015; 115:760-7. [DOI: 10.1016/j.carbpol.2014.06.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 06/20/2014] [Accepted: 06/24/2014] [Indexed: 11/28/2022]
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16
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Li PX, Li ZX, Shen HH, Thomas RK, Penfold J, Lu JR. Application of the Gibbs equation to the adsorption of nonionic surfactants and polymers at the air-water interface: comparison with surface excesses determined directly using neutron reflectivity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9324-9334. [PMID: 23758191 DOI: 10.1021/la4018344] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Four recent papers by Menger et al. have questioned methods of analysis of surface tension (ST) data that use the Gibbs equation to obtain the surface excess (Γ) of a surfactant at the air-water interface. There have been two responses which challenge the assertions of Menger et al. and a response from Menger et al. We use directly determined values of Γ from a range of neutron reflectometry (NR) data to examine some of the issues that are relevant to these seven papers. We show that there is excellent agreement between NR measurements and careful ST analyses for a wide range of nonionic adsorbents, including surfactants and polymers. The reason it is possible to obtain good agreement near the critical micelle concentration (CMC) is that nonionic surfactants generally seem to saturate the surface before the CMC is reached and this makes it relatively easy to determine the limiting slope (and hence Γ) of the ST-log(concentration) plot at the CMC. Furthermore, there is also generally good agreement between ST and NR over the whole range of concentrations below the CMC until depletion effects become important. Depletion effects are shown to become important at higher concentrations than expected, which brings them into the range of many experiments, including techniques other than ST and NR. This is illustrated with new measurements on the biosurfactant surfactin. The agreement between ST and NR outside the depletion range can be regarded as a mutual validation of the two methods, especially as it is demonstrated independently of any model adsorption isotherms. In the normal experimental situation NR is less vulnerable to depletion than ST and we show how NR and a single ST measurement can be used to determine the hitherto undetermined CMC of the nonionic surfactant C18E12, which is found to be 1.3 × 10(-6) M.
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Affiliation(s)
- Pei Xun Li
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
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17
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Prasitnok K, Wilson MR. A coarse-grained model for polyethylene glycol in bulk water and at a water/air interface. Phys Chem Chem Phys 2013; 15:17093-104. [DOI: 10.1039/c3cp52958d] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Park HW, Choi J, Ohn K, Lee H, Kim JW, Won YY. Study of the air-water interfacial properties of biodegradable polyesters and their block copolymers with poly(ethylene glycol). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11555-11566. [PMID: 22830444 DOI: 10.1021/la300810q] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
It has been reported that the surface pressure-area isotherm of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) at the air-water interface exhibits several interesting features: (1) a plateau at intermediate compression levels, (2) a sharp rise in surface pressure upon further compression, and (3) marked surface pressure-area hysteresis during compression-expansion cycles. To investigate the molecular origin of this behavior, we conducted an extensive set of surface pressure and AFM imaging measurements with PLGA materials having several different molecular weights and also a poly(D,L-lactic acid-ran-glycolic acid-ran-caprolactone) (PLGACL) material in which the caprolactone monomers were incorporated as a plasticizing component. The results suggest that (i) the plateau in the surface pressure-area isotherm of PLGA (or PLGACL) occurs because of the formation (and collapse) of a continuous monolayer of the polymer under continuous compression; (ii) the PLGA monolayer becomes significantly resistant to compression at high compression because under that condition the collapsed domains become large enough to become glassy (such behavior was not observed in the nonglassy PLGACL sample); and (iii) the isotherm hysteresis is due to a coarsening of the collapsed domains that occurs under high-compression conditions. We also investigated the monolayer properties of PEG-PLGA and PEG-PLGACL diblock copolymers. The results demonstrate that the tendency of PLGA (or PLGACL) to spread on water allows the polymer to be used as an anchoring block to form a smooth biodegradable monolayer of block copolymers at the air-water interface. These diblock copolymer monolayers exhibit protein resistance.
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Affiliation(s)
- Hae-Woong Park
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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19
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Lee H, Kim DH, Park HW, Mahynski NA, Kim K, Meron M, Lin B, Won YY. Reduced Water Density in a Poly(ethylene oxide) Brush. J Phys Chem Lett 2012; 3:1589-1595. [PMID: 26285713 DOI: 10.1021/jz3002772] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A model poly(ethylene oxide) (PEO) brush system, prepared by spreading a poly(ethylene oxide)-poly(n-butyl acrylate) (PEO-PnBA) amphiphilic diblock copolymer onto an air-water interface, was investigated under various grafting density conditions by using the X-ray reflectivity (XR) technique. The overall electron density profiles of the PEO-PnBA monolayer in the direction normal to the air-water interface were determined from the XR data. From this analysis, it was found that inside of the PEO brush, the water density is significantly lower than that of bulk water, in particular, in the region close to the PnBA-water interface. Separate XR measurements with a PnBA homopolymer monolayer confirm that the reduced water density within the PEO-PnBA monolayer is not due to unfavorable contacts between the PnBA surface and water. The above result, therefore, lends support to the notion that PEO chains provide a hydrophobic environment for the surrounding water molecules when they exist as polymer brush chains.
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Affiliation(s)
- Hoyoung Lee
- †School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Dae Hwan Kim
- †School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Hae-Woong Park
- †School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Nathan A Mahynski
- †School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kyungil Kim
- ‡Advanced Photon Source, University of Chicago, Argonne, Illinois 60439, United States
| | - Mati Meron
- ‡Advanced Photon Source, University of Chicago, Argonne, Illinois 60439, United States
| | - Binhua Lin
- ‡Advanced Photon Source, University of Chicago, Argonne, Illinois 60439, United States
| | - You-Yeon Won
- †School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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20
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Lee H, Kim DH, Witte KN, Ohn K, Choi J, Akgun B, Satija S, Won YY. Water Is a Poor Solvent for Densely Grafted Poly(ethylene oxide) Chains: A Conclusion Drawn from a Self-Consistent Field Theory-Based Analysis of Neutron Reflectivity and Surface Pressure–Area Isotherm Data. J Phys Chem B 2012; 116:7367-78. [PMID: 22616550 DOI: 10.1021/jp301817e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Hoyoung Lee
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
| | - Dae Hwan Kim
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
| | - Kevin N. Witte
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
| | - Kimberly Ohn
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
| | - Je Choi
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
| | - Bulent Akgun
- NIST Center for Neutron Research
(NCNR), National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, United States
- Department of Materials
Science and Engineering, University of Maryland, College Park, Maryland, United States
| | - Sushil Satija
- NIST Center for Neutron Research
(NCNR), National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, United States
| | - You-Yeon Won
- School of Chemical
Engineering, Purdue University, West Lafayette, Indiana, United States
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21
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Darvas M, Gilányi T, Jedlovszky P. Adsorption of Poly(ethylene oxide) at the Free Water Surface. A Computer Simulation Study. J Phys Chem B 2010; 114:10995-1001. [DOI: 10.1021/jp1034272] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mária Darvas
- Laboratory of Interfaces and Nanosize Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány P. Stny 1/A, H-1117 Budapest, Hungary, Institut UTINAM−UMR CNRS 6213, Faculté des Sciences, Université de Franche-Comté, F-25030 Besançon Cedex, France, HAS Research Group of Technical Analytical Chemistry, Szt. Gellért tér 4, H-1111 Budapest, Hungary, and EKF Department of Chemistry, Leányka utca 6, H-3300 Eger, Hungary
| | - Tibor Gilányi
- Laboratory of Interfaces and Nanosize Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány P. Stny 1/A, H-1117 Budapest, Hungary, Institut UTINAM−UMR CNRS 6213, Faculté des Sciences, Université de Franche-Comté, F-25030 Besançon Cedex, France, HAS Research Group of Technical Analytical Chemistry, Szt. Gellért tér 4, H-1111 Budapest, Hungary, and EKF Department of Chemistry, Leányka utca 6, H-3300 Eger, Hungary
| | - Pál Jedlovszky
- Laboratory of Interfaces and Nanosize Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány P. Stny 1/A, H-1117 Budapest, Hungary, Institut UTINAM−UMR CNRS 6213, Faculté des Sciences, Université de Franche-Comté, F-25030 Besançon Cedex, France, HAS Research Group of Technical Analytical Chemistry, Szt. Gellért tér 4, H-1111 Budapest, Hungary, and EKF Department of Chemistry, Leányka utca 6, H-3300 Eger, Hungary
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22
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Willmer D, Baldwin KA, Kwartnik C, Fairhurst DJ. Growth of solid conical structures during multistage drying of sessile poly(ethylene oxide) droplets. Phys Chem Chem Phys 2010; 12:3998-4004. [PMID: 20379491 DOI: 10.1039/b922727j] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sessile droplets of aqueous poly(ethylene oxide) solution, with average molecular weight of 100 kDa, are monitored during evaporative drying at ambient conditions over a range of initial concentrations c(0). For all droplets with c(0) > or = 3%, central conical structures, which can be hollow and nearly 50% taller than the initial droplet, are formed during a growth stage. Although the formation of superficially similar structures has been explained for glass-forming polymers using a skin-buckling model which predicts the droplet to have constant surface area during the growth stage (L. Pauchard and C. Allain, Europhys. Lett., 2003, 62, 897-903), we demonstrate that this model is not applicable here as the surface area is shown to increase during growth for all c(0). We interpret our experimental data using a proposed drying and deposition process comprising the four stages: pinned drying; receding contact line; "bootstrap" growth, during which the liquid droplet is lifted upon freshly-precipitated solid; and late drying. Additional predictions of our model, including a criterion for predicting whether a conical structure will form, compare favourably with observations. We discuss how the specific chemical and physical properties of PEO, in particular its amphiphilic nature, its tendency to form crystalline spherulites rather than an amorphous glass at high concentrations and its anomalous surface tension values for MW = 100 kDa may be critical to the observed drying process.
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Affiliation(s)
- David Willmer
- Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK
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23
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Witte KN, Hur J, Sun W, Kim S, Won YY. Evidence of Lateral Nanoscale Heterogeneities in Weak Polyelectrolyte Brushes. Macromolecules 2008. [DOI: 10.1021/ma801412u] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kevin N. Witte
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - Jaehyun Hur
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - Wei Sun
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - Sangtae Kim
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - You-Yeon Won
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907
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24
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Xuyen NT, Ra EJ, Geng HZ, Kim KK, An KH, Lee YH. Enhancement of Conductivity by Diameter Control of Polyimide-Based Electrospun Carbon Nanofibers. J Phys Chem B 2007; 111:11350-3. [PMID: 17850139 DOI: 10.1021/jp075541q] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxydianiline-pyromellitic dianhydride poly(amic acid) (ODA-PMDA PAA) was polymerized with a catalyst support of triethyl amine for controlling molecular weight. This polymer was used for electrospinning in the preparation of PAA nanofibers, a precursor of carbon nanofibers. Here the amount of catalyst and concentration of PAA solution were optimized to produce polyimide-based carbon nanofibers approximately 80 nm in diameter. The effects of molecular weight of PAA, bias voltage, and spinning rate on the morphology of electrospun PAA and polyimide nanofibers have been evaluated. We showed that the conductivity of the carbon nanofiber mat decreased with increasing nanofiber diameter, where the conductivity of polyimide-based carbon nanofiber mat was much higher than those of other types of carbon nanofiber mat. The key ingredient to increase conductivity in a carbon nanofiber mat was found to be the number of cross junctions between nanofibers.
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Affiliation(s)
- Nguyen Thi Xuyen
- Department of Nanoscience and Nanotechnology, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 440-746, South Korea
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25
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Díez-Pascual AM, Compostizo A, Crespo-Colín A, Rubio RG, Miller R. Adsorption of water-soluble polymers with surfactant character. J Colloid Interface Sci 2007; 307:398-404. [PMID: 17222418 DOI: 10.1016/j.jcis.2006.11.056] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 11/30/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022]
Abstract
A comparative study between Langmuir and Gibbs monolayers of a hyperbranched polyol, poly(propylene glycol) homopolymers, and poly(propylene glycol)-poly(ethylene glycol) copolymers with different structure and molecular weight, is reported. Dynamic surface tension (DST) and surface pressure measurements have been carried out to characterize these amphiphilic water-soluble polymers. The adsorption kinetics results are consistent with a rapid diffusion stage followed by a slow reorganization at the air-water interface. The characteristic times of these steps, calculated by the Joos model, point out differences among the polymers in the diffusion rate and rearrangement mechanisms for diluted solutions. Short time analysis of DST data leads to diffusion coefficients in qualitative agreement with the diffusion times calculated with Joos' model. Spread monolayers remain stable for long periods of time. The desorption process seems quite inoperative. As a consequence, the surface pressure of the spread monolayers can be studied over a broad surface concentration range. 2D first-order phase transitions have been evidenced from plateaux observed in Langmuir and Gibbs isotherms. It has been found that Gibbs monolayers lead to lower surface tension states than the Langmuir ones.
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Affiliation(s)
- Ana M Díez-Pascual
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
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26
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Gilányi T, Varga I, Gilányi M, Mészáros R. Adsorption of poly(ethylene oxide) at the air/water interface: A dynamic and static surface tension study. J Colloid Interface Sci 2006; 301:428-35. [PMID: 16780860 DOI: 10.1016/j.jcis.2006.05.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 05/15/2006] [Accepted: 05/16/2006] [Indexed: 11/30/2022]
Abstract
The adsorption of polyethylene oxide (PEO) homologues in a wide range of molecular weight (from M(PEO)=200 to 10(6)) at the air/aqueous solution interface was investigated by dynamic and static surface tension measurements. An approximate estimate for the lower limit of PEO concentration was given at which reliable equilibrium surface tension can be determined from static surface tension measurements. It was shown that the observed jump in the earlier published sigma-lg(c(PEO)) curves is attributable to the nonequilibrium surface tension values at low PEO concentrations. The adsorption behavior of short chain PEO molecules (M(PEO)1000) is similar to that of the ordinary surfactants. The estimated standard free energy of PEO adsorption, DeltaG(0), increases linearly with the PEO molecular weight until M(PEO)=1000. In this molecular weight range, DeltaG(0) was found to be approximately the fifth of the hydrophobic driving force related to the adsorption of a surfactant with the same number of methylene groups. In the case of the longer chain PEOs the driving force of adsorption is so high that the adsorption isotherm is near saturation in the experimentally available polymer concentration range. Above a critical molecular weight the PEO adsorption reveals universal features, e.g., the surface tension and the surface density of segments do not depend on the polymer molecular weight.
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Affiliation(s)
- Tibor Gilányi
- Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry, Eötvös Loránd University, Budapest H-1117, Pázmány Péter sétány 1/A, Hungary
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27
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Cheyne RB, Moffitt MG. Novel two-dimensional "ring and chain" morphologies in Langmuir-Blodgett monolayers of PS-b-PEO block copolymers: effect of spreading solution concentration on self-assembly at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:5453-60. [PMID: 15924475 DOI: 10.1021/la0503707] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A polystyrene-b-poly(ethylene oxide) (PS-b-PEO) (MW = 141k, 11.4 wt% PEO) diblock copolymer in the hydrophobic regime was spread from chloroform solutions of various concentrations at the air-water interface, and the resultant monolayers were transferred to glass substrates and imaged using atomic force microscopy. Monolayers prepared under identical conditions were also characterized at the air-water interface via Langmuir compression isotherms. The effects of spreading solution concentration on surface features, compressibility, and limiting mean molecular area were determined, revealing several interesting trends that have not been reported for other systems of PS-b-PEO. Spreading solutions > or = 0.50 mg/mL resulted almost exclusively in dot and spaghetti morphologies, with no observed continent features, which have been commonly found in more hydrophobic systems. For lower spreading solutions, < or = 0.25 mg/mL, we observed a large predominance of two novel surface morphologies, nanoscale rings and chains. The surface pressure (pi)-area (A) isotherms also exhibited a unique dependence on the spreading solution concentration, with limiting mean molecular areas and isothermal compressibilities of PS-b-PEO monolayers increasing below a critical concentration of spreading solution, suggesting a greater contribution from the PEO blocks. These results suggest that PS chain entanglement prior to solvent evaporation plays an important kinetic role in the extent of PEO adsorption at the air-water interface and in the morphologies of the resulting self-assembled surface aggregates.
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Affiliation(s)
- Robert B Cheyne
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6 Canada
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28
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Bosker WTE, Iakovlev PA, Norde W, Cohen Stuart MA. BSA adsorption on bimodal PEO brushes. J Colloid Interface Sci 2005; 286:496-503. [PMID: 15897063 DOI: 10.1016/j.jcis.2005.01.091] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2004] [Accepted: 01/24/2005] [Indexed: 11/26/2022]
Abstract
BSA adsorption onto bimodal PEO brushes at a solid surface was measured using optical reflectometry. Bimodal brushes consist of long (N=770) and short (N=48) PEO chains and were prepared on PS surfaces, applying mixtures of PS(29)-PEO(48) and PS(37)-PEO(770) block copolymers and using the Langmuir-Blodgett technique. Pi-A isotherms of (mixtures of) the block copolymers were measured to establish the brush regime. The isotherms of PS(29)-PEO(48) show hysteresis between compression and expansion cycles, indicating aggregation of the PS(29)-PEO(48) upon compression. Mixtures of PS(29)-PEO(48) and PS(37)-PEO(770) demonstrate a similar hysteresis effect, which eventually vanishes when the ratio of PS(37)-PEO(770) to PS(29)-PEO(48) is increased. The adsorption of BSA was determined at brushes for which the grafting density of the long PEO chains was varied, while the total grafting density was kept constant. BSA adsorption onto monomodal PEO(48) and PEO(770) brushes was determined for comparison. The BSA adsorption behavior of the bimodal brushes is similar to the adsorption of BSA at PEO(770) monomodal brushes. The maximum of BSA adsorption at low grafting density of PEO(770) can be explained by ternary adsorption, implying an attraction between BSA and PEO. The contribution of primary adsorption to the total adsorbed amount is negligible.
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Affiliation(s)
- W T E Bosker
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands.
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29
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Muñoz MG, Encinar M, Bonales LJ, Ortega F, Monroy F, Rubio RG. Surface Light-Scattering at the Air−Liquid Interface: From Newtonian to Viscoelastic Polymer Solutions. J Phys Chem B 2005; 109:4694-9. [PMID: 16851550 DOI: 10.1021/jp044811r] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamics of the liquid-air interface of aqueous solutions of a tensioactive triblock copolymer (Pluronic F-68) has been studied using surface quasielastic light scattering over a broad range of concentrations and temperatures. Ancillary surface tension and bulk rheometry data have been obtained for the same system. The results show that the classical theoretical spectrum for monolayers on a Newtonian fluid can be applied only for concentrations below 4.10(-2) mM. For concentrations above c = 14 mM a clear peak centered at zero frequency appears in the spectrum. This feature is incompatible with the classical theoretical spectrum. The SQELS spectra have been described in terms of the theory of Wang and Huang [Wang, C. H.; Huang, Q. R. J. Chem. Phys. 1997, 107, 5898] considering that the loss modulus of the concentrated solutions shows the existence of two relaxation modes even at low frequencies. The theory is able to explain the existence of a peak centered at zero frequency in the spectra, and the theoretical spectra point out the existence of an elastic peak together with the capillary one. There is a reasonable agreement between the relaxation times and the product Gtau obtained from the fits of the SQELS spectra to the theory of Wang and Huang and those obtained from bulk rheology.
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Affiliation(s)
- Mercedes G Muñoz
- Department Química Física I, Fac. Química, University Complutense, 28040-Madrid, Spain
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30
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Zeno E, Beneventi D, Carré B. Interactions between poly(ethylene oxide) and fatty acids sodium salts studied by surface tension measurements. J Colloid Interface Sci 2004; 277:215-20. [PMID: 15276059 DOI: 10.1016/j.jcis.2004.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Accepted: 04/16/2004] [Indexed: 11/30/2022]
Abstract
This work focuses onto the interactions between poly(ethylene oxide) (PEO) and fatty acids, in order to set their potential role of contaminants for PEO-based retention systems. Surface tension measurements were used to investigate PEO-fatty acid systems and they made it possible to clearly point out the interactions between the polymer and the sodium octadecylcarboxylates with different degrees of unsaturation. The observed interaction seems to be dependent on the fatty acids' solubility, the increase of which leads to less pronounced phenomena, which are, in contrast, emphasized by the increase in PEO chain length.
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Affiliation(s)
- Elisa Zeno
- Ecole Française de Papeterie et des Industries Graphiques, B.P. 65, 38402 St-Martin d'Hères, France.
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31
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Zhang D, Ortiz C. Synthesis and Single Molecule Force Spectroscopy of Graft Copolymers of Poly(2-hydroxyethyl methacrylate-g-ethylene glycol). Macromolecules 2004. [DOI: 10.1021/ma035065b] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Urzua MD, Cabrera WJ, Ríos HE. Surface properties of poly(N-monoalkylmaleamic acid-alt-styrene) sodium salts: effect of the molecular weight and the side chain length. J Colloid Interface Sci 2003; 264:284-9. [PMID: 12885547 DOI: 10.1016/s0021-9797(03)00351-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The surface properties of poly(N-monoalkylmaleamic acid-alt-styrene) sodium salts are studied as a function of the molecular weight and the size of the linear alkyl lateral chain of the polyelectrolyte. The experimental results are well described by the Gibbs-Szyszkowski treatment. Both the surface tension behavior and the standard free energy of adsorption depend on the polyelectrolyte side chain and on the average molecular weight, M(w). An M(w)-dependent contribution to the free energy of adsorption ranging from -1.21 to -1.05 kJ for mole of methylene groups is found. The area covered by monomer units increases with M(w) and the sizes of side chains are similar to those reported in small-molecule systems. The nature of the functional group amide in the side chain has practically no effect on the surface properties as compared with the ester group in this kind of polyelectrolytes.
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Affiliation(s)
- Marcela D Urzua
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Casilla 653, Correo Central, Santiago, Chile
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Currie EPK, Norde W, Cohen Stuart MA. Tethered polymer chains: surface chemistry and their impact on colloidal and surface properties. Adv Colloid Interface Sci 2003; 100-102:205-65. [PMID: 12668330 DOI: 10.1016/s0001-8686(02)00061-1] [Citation(s) in RCA: 306] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this review the grafting of polymer chains to solid supports or interfaces and the subsequent impact on colloidal properties is examined. We start by examining theoretical models for densely grafted polymers (brushes), experimental techniques for their preparation and the properties of the ensuing structures. Our aim is to present a broad overview of the state of the art in this field, rather than an in-depth study. In the second section the interactions of surfaces with tethered polymers with the surrounding environment and the impact on colloidal properties are considered. Various theoretical models for such interactions are discussed. We then review the properties of colloids with tethered polymer chains, interactions between planar brushes and nanocolloids, interactions between brushes and biocolloids and the impact of grafted polymers on wetting properties of surfaces, using the ideas presented in the first section. The review closes with an outlook to possible new directions of research.
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Affiliation(s)
- E P K Currie
- Material Science Center, DSM Research, 6160 MD, Geleen, The Netherlands
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34
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Leckband D, Sheth S, Halperin A. Grafted poly(ethylene oxide) brushes as nonfouling surface coatings. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1999; 10:1125-47. [PMID: 10591136 DOI: 10.1163/156856299x00720] [Citation(s) in RCA: 280] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The identification of design criteria for the prevention of surface fouling by protein adsorption has been an elusive research goal. The current ideas in this domain assume two different directions. One focuses on correlating protein adsorption with macroscopic surface properties such as the water wettability. The second approach involves tailoring the molecular interactions between the adsorbing proteins and the surface. In this paper, we focus on the experimental results and theoretical ideas concerned with tuning the interfacial forces by means of terminally grafted PEO chains.
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Affiliation(s)
- D Leckband
- Department of Chemical Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
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35
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Currie EPK, Wagemaker M, Cohen Stuart MA, van Well AA. Structure of Monodisperse and Bimodal Brushes. Macromolecules 1999. [DOI: 10.1021/ma990936w] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. P. K. Currie
- Department of Physical and Colloid Chemistry, Wageningen University, The Netherlands, and Interfaculty Reactor Institute, Delft University of Technology, The Netherlands
| | - M. Wagemaker
- Department of Physical and Colloid Chemistry, Wageningen University, The Netherlands, and Interfaculty Reactor Institute, Delft University of Technology, The Netherlands
| | - M. A. Cohen Stuart
- Department of Physical and Colloid Chemistry, Wageningen University, The Netherlands, and Interfaculty Reactor Institute, Delft University of Technology, The Netherlands
| | - A. A. van Well
- Department of Physical and Colloid Chemistry, Wageningen University, The Netherlands, and Interfaculty Reactor Institute, Delft University of Technology, The Netherlands
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Fauré MC, Bassereau P, Lee LT, Menelle A, Lheveder C. Phase Transitions in Monolayers of PS−PEO Copolymer at the Air−Water Interface. Macromolecules 1999. [DOI: 10.1021/ma9900840] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - C. Lheveder
- Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05, France
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37
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Currie EPK, Leermakers FAM, Cohen Stuart MA, Fleer GJ. Grafted Adsorbing Polymers: Scaling Behavior and Phase Transitions. Macromolecules 1999. [DOI: 10.1021/ma970525k] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E. P. K. Currie
- Department of Physical and Colloid Chemistry, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| | - F. A. M. Leermakers
- Department of Physical and Colloid Chemistry, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| | - M. A. Cohen Stuart
- Department of Physical and Colloid Chemistry, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| | - G. J. Fleer
- Department of Physical and Colloid Chemistry, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
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Warriner HE, Keller SL, Idziak SH, Slack NL, Davidson P, Zasadzinski JA, Safinya CR. The influence of polymer molecular weight in lamellar gels based on PEG-lipids. Biophys J 1998; 75:272-93. [PMID: 9649387 PMCID: PMC1299699 DOI: 10.1016/s0006-3495(98)77514-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We report x-ray scattering, rheological, and freeze-fracture and polarizing microscopy studies of a liquid crystalline hydrogel called Lalpha,g. The hydrogel, found in DMPC, pentanol, water, and PEG-DMPE mixtures, differs from traditional hydrogels, which require high MW polymer, are disordered, and gel only at polymer concentrations exceeding an "overlap" concentration. In contrast, the Lalpha,g uses very low-molecular-weight polymer-lipids (1212, 2689, and 5817 g/mole), shows lamellar order, and requires a lower PEG-DMPE concentration to gel as water concentration increases. Significantly, the Lalpha,g contains fluid membranes, unlike Lbeta' gels, which gel via chain ordering. A recent model of gelation in Lalpha phases predicts that polymer-lipids both promote and stabilize defects; these defects, resisting shear in all directions, then produce elasticity. We compare our observations to this model, with particular attention to the dependence of gelation on the PEG MW used. We also use x-ray lineshape analysis of scattering from samples spanning the fluid-gel transition to obtain the elasticity coefficients kappa and B; this analysis demonstrates that although B in particular depends strongly on PEG-DMPE concentration, gelation is uncorrelated to changes in membrane elasticity.
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Affiliation(s)
- H E Warriner
- Materials Research Laboratory, Materials Department, University of California, Santa Barbara, California 93106, USA
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39
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Booth C, Richards RW, Taylor MR, Yu GE. Surface Quasielastic Light Scattering from Spread Films of Cyclic Poly(ethylene oxide). J Phys Chem B 1998. [DOI: 10.1021/jp980008j] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Booth
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham DH1 3LE, UK, and Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - R. W. Richards
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham DH1 3LE, UK, and Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - M. R. Taylor
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham DH1 3LE, UK, and Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - G.-E. Yu
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham DH1 3LE, UK, and Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
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40
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Warriner HE, Davidson P, Slack NL, Schellhorn M, Eiselt P, Idziak SHJ, Schmidt HW, Safinya CR. Lamellar biogels comprising fluid membranes with a newly synthesized class of polyethylene glycol-surfactants. J Chem Phys 1997. [DOI: 10.1063/1.474726] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Sheth SR, Leckband D. Measurements of attractive forces between proteins and end-grafted poly(ethylene glycol) chains. Proc Natl Acad Sci U S A 1997; 94:8399-404. [PMID: 9237988 PMCID: PMC22932 DOI: 10.1073/pnas.94.16.8399] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The surface force apparatus was used to measure directly the molecular forces between streptavidin and lipid bilayers displaying grafted Mr 2,000 poly(ethylene glycol) (PEG). These measurements provide direct evidence for the formation of relatively strong attractive forces between PEG and protein. At low compressive loads, the forces were repulsive, but they became attractive when the proteins were pressed into the polymer layer at higher loads. The adhesion was sufficiently robust that separation of the streptavidin and PEG uprooted anchored polymer from the supporting membrane. These interactions altered the properties of the grafted chains. After the onset of the attraction, the polymer continued to bind protein for several hours. The changes were not due to protein denaturation. These data demonstrate directly that the biological activity of PEG is not due solely to properties of simple polymers such as the excluded volume. It is also coupled to the competitive interactions between solvent and other materials such as proteins for the chain segments and to the ability of this material to adopt higher order intrachain structures.
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Affiliation(s)
- S R Sheth
- Department of Chemical Engineering, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
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42
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Richards RW, Taylor MR. Relaxation Processes in Surface Excess Layers of Aqueous Solutions of Poly(ethylene oxide). Macromolecules 1997. [DOI: 10.1021/ma961684r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. W. Richards
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham, DH1 3LE, U.K
| | - M. R. Taylor
- Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, Durham, DH1 3LE, U.K
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Warriner HE, Idziak SH, Slack NL, Davidson P, Safinya CR. Lamellar biogels: fluid-membrane-based hydrogels containing polymer lipids. Science 1996; 271:969-73. [PMID: 8584932 DOI: 10.1126/science.271.5251.969] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A class of lamellar biological hydrogels comprised of fluid membranes of lipids and surfactants with small amounts of low molecular weight poly(ethylene glycol)-derived polymer lipids (PEG-lipids) were studied by x-ray diffraction, polarized light microscopy, and rheometry. In contrast to isotropic hydrogels of polymer networks, these membrane-based birefringent liquid crystalline biogels, labeled L-alpha,g, form the gel phase when water is added to the liquid-like lamellar L-alpha phase, which reenters a liquid-like mixed phase upon further dilution. Furthermore, gels with larger water content require less PEG-lipid to remain stable. Although concentrated (approximately 50 weight percent) mixtures of free PEG (molecular weight, 5000) and water do not gel, gelation does occur in mixtures containing as little as 0.5 weight percent PEG-lipid. A defining signature of the L-alpha,g regime as it sets in from the fluid lamellar L-alpha phase is the proliferation of layer-dislocation-type defects, which are stabilized by the segregation of PEG-lipids to the defect regions of high membrane curvature that connect the membranes.
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Affiliation(s)
- H E Warriner
- Materials Research Laboratory, Materials Department, University of California, Santa Barbara 93106, USA
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