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Gao X, Yang Z, Zhang W, Pan B. Carbon redirection via tunable Fenton-like reactions under nanoconfinement toward sustainable water treatment. Nat Commun 2024; 15:2808. [PMID: 38561360 PMCID: PMC10985074 DOI: 10.1038/s41467-024-47269-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 03/26/2024] [Indexed: 04/04/2024] Open
Abstract
The ongoing pattern shift in water treatment from pollution control to energy recovery challenges the energy-intensive chemical oxidation processes that have been developed for over a century. Redirecting the pathways of carbon evolution from molecular fragmentation to polymerization is critical for energy harvesting during chemical oxidation, yet the regulation means remain to be exploited. Herein, by confining the widely-studied oxidation system-Mn3O4 catalytic activation of peroxymonosulfate-inside amorphous carbon nanotubes (ACNTs), we demonstrate that the pathways of contaminant conversion can be readily modulated by spatial nanoconfinement. Reducing the pore size of ACNTs from 120 to 20 nm monotonously improves the pathway selectivity toward oligomers, with the yield one order of magnitude higher under 20-nm nanoconfinement than in bulk. The interactions of Mn3O4 with ACNTs, reactant enrichment, and pH lowering under nanoconfinement are evidenced to collectively account for the enhanced selectivity toward polymerization. This work provides an adaptive paradigm for carbon redirection in a variety of catalytic oxidation processes toward energy harvesting and sustainable water purification.
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Affiliation(s)
- Xiang Gao
- State Key Laboratory of Pollution Control and Resources Reuse, Nanjing University, Nanjing, China
| | - Zhichao Yang
- State Key Laboratory of Pollution Control and Resources Reuse, Nanjing University, Nanjing, China
- Research Center for Environmental Nanotechnology (ReCENT), School of Environment, Nanjing University, Nanjing, China
| | - Wen Zhang
- John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resources Reuse, Nanjing University, Nanjing, China.
- Research Center for Environmental Nanotechnology (ReCENT), School of Environment, Nanjing University, Nanjing, China.
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2
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Milchev A, Petkov P. Concave polymer brushes inwardly grafted in spherical cavities. J Chem Phys 2023; 158:094903. [PMID: 36889952 DOI: 10.1063/5.0141450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
The structure and scaling properties of inwardly curved polymer brushes, tethered under good solvent conditions to the inner surface of spherical shells such as membranes and vesicles, are studied by extensive molecular dynamics simulations and compared with earlier scaling and self-consistent field theory predictions for different molecular weights of the polymer chains N and grafting densities σg in the case of strong surface curvature, R-1. We examine the variation of the critical radius R*(σg), separating the regimes of weak concave brushes and compressed brushes, predicted earlier by Manghi et al. [Eur. Phys. J. E 5, 519-530 (2001)], as well as various structural properties such as the radial monomer- and chain-end density profiles, orientation of bonds, and brush thickness. The impact of chain stiffness, κ, on concave brush conformations is briefly considered as well. Eventually, we present the radial profiles of the local pressure normal, PN, and tangential, PT, to the grafting surface, and the surface tension γ(σg), for soft and rigid brushes, and find a new scaling relationship PN(R)∝σg 4, independent of the degree of chain stiffness.
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Affiliation(s)
- Andrey Milchev
- Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Peicho Petkov
- Sofia University St. Kliment Ohridski, Faculty of Physics, Sofia, Bulgaria
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3
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Li CW, Romeis D, Koch M, Merlitz H, Sommer JU. Theoretical analysis of the elastic free energy contributions to polymer brushes in poor solvent: A refined mean-field theory. J Chem Phys 2022; 157:104902. [DOI: 10.1063/5.0103351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We consider polymer brushes in poor solvent that are grafted onto planar substrates and onto the internal and external surfaces of a cylinder using molecular dynamics simulation, self-consistent field (SCF), and mean-field theory. We derive a unified expression for the mean field free energy for the three geometrical classes. While for low grafting densities, the effect of chain elasticity can be neglected in poor solvent conditions, it becomes relevant at higher grafting densities and, in particular, for concave geometries. Based on the analysis of the end monomer distribution, we introduce an analytical term that describes the elasticity as a function of grafting density. The accuracy of the model is validated with molecular dynamics simulations as well as SCF computations and shown to yield precise values for the layer thickness over a wide range of system parameters. We further apply this model to analyze the gating behavior of switchable brushes inside nanochannels.
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Affiliation(s)
- Cheng-Wu Li
- Leibniz-Institut of Polymer Research Dresden, 01069 Dresden, Germany
| | - Dirk Romeis
- Leibniz-Institut of Polymer Research Dresden, 01069 Dresden, Germany
| | - Markus Koch
- Leibniz-Institut of Polymer Research Dresden, 01069 Dresden, Germany
| | - Holger Merlitz
- Leibniz-Institut of Polymer Research Dresden, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz-Institut of Polymer Research Dresden, 01069 Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, Zellescher Weg 13, Dresden, Germany
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4
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Pastorino C, Müller M. Liquid and Droplet Transport in Brush-Coated Cylindrical Nanochannels: Brush-Assisted Droplet Formation. J Phys Chem B 2021; 125:442-449. [PMID: 33400523 DOI: 10.1021/acs.jpcb.0c09189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We study, by coarse-grained molecular dynamics simulations, equilibrium and flow properties of a liquid in cylindrical nanochannels, coated with polymer brushes. The parameters of the interaction potential model confer a chemical incompatibility between brush monomers and liquid particles. First, we study cylindrical channels whose radii are larger than the brush height and a continuous column of liquid forms at the center of the channel. These results are contrasted to the limiting case in which the radius of the cylinder is comparable to the brush height. In this second case, the grafted polymers interact across the channel and "close" it. We observe a train of droplets as the stable liquid morphology. The droplet size is comparable to the cylinder radius. By applying a constant body force onto the liquid, we induce a Poiseuille-like flow and investigate the morphology and flow rate as a function of driving force. Upon increasing the driving force, we encounter a nonequilibrium transition from a closed channel with slowly moving droplets to a flowing liquid thread at the center. The switching between these two states is reversible.
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Affiliation(s)
- C Pastorino
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA, Av.Gral. Paz 1499, B1650 San Martín, Pcia. de Buenos Aires, Argentina.,Instituto de Nanociencia y Nanotecnología CONICET-CNEA, B1650 Buenos Aires, Argentina
| | - M Müller
- Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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Bayat H, Raoufi M, Zamrik I, Schönherr H. Poly(diethylene glycol methylether methacrylate) Brush-Functionalized Anodic Alumina Nanopores: Curvature-Dependent Polymerization Kinetics and Nanopore Filling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2663-2672. [PMID: 32073275 DOI: 10.1021/acs.langmuir.9b03700] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on the synthesis and characterization of poly(diethylene glycol methylether methacrylate) (PDEGMA) brushes by surface-initiated atom transfer radical polymerization inside ordered cylindrical nanopores of anodic aluminum oxide with different pore radii between 20 and 185 nm. In particular, the dependence of polymerization kinetics and the degree of pore filling on the interfacial curvature were analyzed. On the basis of field emission scanning electron microscopy data and thermal gravimetric analysis (TGA), it was concluded that the polymerization rate was faster at the pore orifice compared to the pore interior and also as compared to the analogous reaction carried out on flat aluminum oxide substrates. The apparent steady-state polymerization rate near the orifice increased with decreasing pore size. Likewise, the overall apparent polymerization rate estimated from TGA data indicated stronger confinement for pores with increased curvature as well as increased mass transport limitations due to the blockage of the pore orifice. Only for pores with a diameter to length ratio of ∼1, PDEGMA brushes were concluded to grow uniformly with constant thickness. However, because of mass transport limitations in longer pores, incomplete pore filling was observed, which leads presumably to a PDEGMA gradient brush. This study contributes to a better understanding of polymer brush-functionalized nanopores and the impact of confinement, in which the control of polymer brush thickness together with grafting density along the nanopores is key for applications of PDEGMA brushes confined inside nanopores.
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Affiliation(s)
- Haider Bayat
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Mohammad Raoufi
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Imad Zamrik
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Holger Schönherr
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
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6
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Zoppe JO, Ataman NC, Mocny P, Wang J, Moraes J, Klok HA. Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes. Chem Rev 2017; 117:1105-1318. [PMID: 28135076 DOI: 10.1021/acs.chemrev.6b00314] [Citation(s) in RCA: 600] [Impact Index Per Article: 85.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.
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Affiliation(s)
- Justin O Zoppe
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Nariye Cavusoglu Ataman
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Piotr Mocny
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Jian Wang
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - John Moraes
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Harm-Anton Klok
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
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Chen J, Li L, Zhou D, Wang X, Xue G. Effect of geometric curvature on vitrification behavior for polymer nanotubes confined in anodic aluminum oxide templates. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:032306. [PMID: 26465472 DOI: 10.1103/physreve.92.032306] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Indexed: 06/05/2023]
Abstract
The glass transition behavior of polystyrene (PS) nanotubes confined in cylindrical alumina nanopores was studied as a function of pore diameter (d) and polymer tube thickness (δ). Both the calorimetric glass transition temperature and the microstructure measured by a nonradiative energy transfer method indicated that the polymer nanotube, or concave polymer thin film, exhibited significant differences in vitrification behavior compared to the planar one. A closer interchain proximity and an increased T_{g} were observed for polymer nanotubes with respect to the bulk polymer. T_{g} for polymer nanotubes was primarily dependent on the curvature radius d of the template, while it was less dependent on the thickness δ of the PS tube wall in the range of 11-23 nm. For small nanotubes (d=55nm), the T_{g} increased as high as 18 °C above the bulk value. This vitrified property reverted back to the bulk value when the substrate was chemically removed, which indicated the crucial importance of the interfacial effect imposed by the hard wall with a concave geometry.
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Affiliation(s)
- Jiao Chen
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Linling Li
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Dongshan Zhou
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Xiaoliang Wang
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Gi Xue
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of High Performance Polymer Materials and Technology (Nanjing University), Ministry of Education, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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8
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Suo T, Whitmore MD. Grafted polymers inside cylindrical tubes: Chain stretching vs layer thickness. J Chem Phys 2013; 138:164907. [DOI: 10.1063/1.4802632] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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9
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Egorov SA. Insertion of nanoparticles into polymer brush under variable solvent conditions. J Chem Phys 2013; 137:134905. [PMID: 23039611 DOI: 10.1063/1.4757017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this work, two-dimensional lattice-based self-consistent field theory is used to study the free energy cost associated with the insertion of a nanoparticle into a polymer brush. The nanoparticle is modeled as a cylinder and the self-consistent field equations are formulated on a cylindrical lattice. The use of two-dimensional formalism makes it possible to take into account the distortion of the brush density profile due to the embedded nanoinclusion. The insertion free energy penalty is analyzed as a function of the particle size, the brush grafting density, and the solvent quality. In agreement with the earlier simulation work, we find that the insertion free energy cost increases both with the particle size and the brush grafting density and decreases with deteriorating solvent quality. For nanoparticles located deep inside the brush, the insertion free energy is shown to scale with either squared (good solvent) or cubed (poor solvent) monomer volume fraction profile, in agreement with the earlier theoretical results. For shallow nanoinclusions located close to the brush surface, the insertion free energy is shown to scale linearly with the monomer volume fraction profile under both good and theta solvent conditions, again in agreement with the earlier work.
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Affiliation(s)
- S A Egorov
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA
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10
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Binder K, Milchev A. Polymer brushes on flat and curved surfaces: How computer simulations can help to test theories and to interpret experiments. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23168] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Cao Q, Zuo C, Li L, Li Y, Yang Y. Translocation of nanoparticles through a polymer brush-modified nanochannel. BIOMICROFLUIDICS 2012; 6:34101. [PMID: 23853678 PMCID: PMC3407119 DOI: 10.1063/1.4732799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 06/16/2012] [Indexed: 06/02/2023]
Abstract
A basic understanding of the transport mechanisms of nanostructures in a polymer brush-modified nanochannel as well as the brush-nanostructure interactions at molecular level is important to design and fabricate emerging smart nano/microfluidic channels. In this work, we report coarse-grained molecular dynamics simulations of the translocation of nanoparticles through a cylindrical nanochannel coated with the polymer brush. The effects of the interparticle interaction and grafting density on the distribution and electrokinetic transport of nanoparticles are addressed in detail. Analysis of the distribution and velocity profiles of nanoparticles from the simulations indicate that the location of nanoparticles along the radial direction and their migration velocity are very sensitive to the change of interparticle interaction. We find complicated transport dynamics of nanoparticles under the influence of various grafting densities. The nanoparticles show markedly different translocation behavior upon increasing the grafting density, which depends on the counterion distribution, free room within the brush, nanoparticle-polymer friction, and brush configuration. Our results may serve as a useful starting point for the transport of nanostructures in polymer-modified channels and help to guide the design of novel smart nanofluidic channels for controlling the migration behavior of nanostructures.
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Affiliation(s)
- Qianqian Cao
- College of Mechanical Science and Engineering, Jilin University, Changchun 130022, China
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