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Robertson H, Gresham IJ, Nelson ARJ, Prescott SW, Webber GB, Wanless EJ. Illuminating the nanostructure of diffuse interfaces: Recent advances and future directions in reflectometry techniques. Adv Colloid Interface Sci 2024; 331:103238. [PMID: 38917595 DOI: 10.1016/j.cis.2024.103238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 06/07/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024]
Abstract
Diffuse soft matter interfaces take many forms, from end-tethered polymer brushes or adsorbed surfactants to self-assembled layers of lipids. These interfaces play crucial roles across a multitude of fields, including materials science, biophysics, and nanotechnology. Understanding the nanostructure and properties of these interfaces is fundamental for optimising their performance and designing novel functional materials. In recent years, reflectometry techniques, in particular neutron reflectometry, have emerged as powerful tools for elucidating the intricate nanostructure of soft matter interfaces with remarkable precision and depth. This review provides an overview of selected recent developments in reflectometry and their applications for illuminating the nanostructure of diffuse interfaces. We explore various principles and methods of neutron and X-ray reflectometry, as well as ellipsometry, and discuss advances in their experimental setups and data analysis approaches. Improvements to experimental neutron reflectometry methods have enabled greater time resolution in kinetic measurements and elucidation of diffuse structure under shear or confinement, while innovation in analysis protocols has significantly reduced data processing times, facilitated co-refinement of reflectometry data from multiple instruments and provided greater-than-ever confidence in proposed structural models. Furthermore, we highlight some significant research findings enabled by these techniques, revealing the organisation, dynamics, and interfacial phenomena at the nanoscale. We also discuss future directions and potential advancements in reflectometry techniques. By shedding light on the nanostructure of diffuse interfaces, reflectometry techniques enable the rational design and tailoring of interfaces with enhanced properties and functionalities.
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Affiliation(s)
- Hayden Robertson
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; Soft Matter at Interfaces, Technical University of Darmstadt, Darmstadt D-64289, Germany
| | - Isaac J Gresham
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - Andrew R J Nelson
- Australian Centre for Neutron Scattering, ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Stuart W Prescott
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Grant B Webber
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Erica J Wanless
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia.
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2
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Le Brun AP, Gilbert EP. Advances in sample environments for neutron scattering for colloid and interface science. Adv Colloid Interface Sci 2024; 327:103141. [PMID: 38631095 DOI: 10.1016/j.cis.2024.103141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/19/2024]
Abstract
This review describes recent advances in sample environments across the full complement of applicable neutron scattering techniques to colloid and interface science. Temperature, pressure, flow, tensile testing, ultrasound, chemical reactions, IR/visible/UV light, confinement, humidity and electric and magnetic field application, as well as tandem X-ray methods, are all addressed. Consideration for material choices in sample environments and data acquisition methods are also covered as well as discussion of current and potential future use of machine learning and artificial intelligence.
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Affiliation(s)
- Anton P Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Elliot Paul Gilbert
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia.
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3
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Lin F, Itoh S, Fukuzawa K, Zhang H, Azuma N. Correlation between viscoelastic response and frictional properties of hydrated zwitterionic polymer brush film in narrowing shear gap. J Colloid Interface Sci 2024; 655:253-261. [PMID: 37944373 DOI: 10.1016/j.jcis.2023.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
HYPOTHESIS A hydrated 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer brush exhibits exceptional lubricity. This lubrication mechanism has traditionally been attributed to either the inherent fluidity of the brush or the water film that forms owing to its hydrophilic nature. Given previous findings that the frictional properties of the MPC polymer brush film show load dependence, we hypothesize that the lubrication mechanism can be elucidated by examining the shear gap (varies owing to the load) dependence of the brush's viscoelastic response. EXPERIMENTS MPC polymer brush films with different thicknesses were prepared. Their viscoelastic responses were evaluated across different shear gap widths, and the frictional properties were subsequently compared across states with distinct viscoelastic behaviors. FINDINGS The observed shear viscoelasticity demonstrated a clear gap dependence that correlated with frictional attributes. Our data suggests that the lubrication mechanism shifts based on the shear gap. Specifically, two states exhibited low coefficients of friction: one where the osmotic pressure supports the load while allowing flexible deformation of the brush film, and the other where the brush film undergoes compression and transitions to a fully elastic state.
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Affiliation(s)
- Fengchang Lin
- Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, 464-8601, Japan
| | - Shintaro Itoh
- Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, 464-8601, Japan; PRESTO, Japan Science and Technology Agency, 102-0076, Japan.
| | - Kenji Fukuzawa
- Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, 464-8601, Japan
| | - Hedong Zhang
- Department of Complex Systems Science, Nagoya University, 464-8601, Japan
| | - Naoki Azuma
- Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, 464-8601, Japan; ACT-X, Japan Science and Technology Agency, 102-0076, Japan
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Qiao Y, He Q, Huang HH, Mastropietro D, Jiang Z, Zhou H, Liu Y, Tirrell MV, Chen W. Stretching of immersed polyelectrolyte brushes in shear flow. NANOSCALE 2023; 15:19282-19291. [PMID: 37997161 DOI: 10.1039/d3nr04187e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
The way that polymer brushes respond to shear flow has important implications in various applications, including antifouling, corrosion protection, and stimuli-responsive materials. However, there is still much to learn about the behaviours and mechanisms that govern these responses. To address this gap in knowledge, our study uses in situ X-ray reflectivity to investigate how poly(styrene sulfonate) (PSS) brushes stretch and change in different environments, such as isopropanol (a poor solvent), water (a good solvent), and aqueous solutions containing various cations (Cs+, Ba2+, La3+, and Y3+). We have designed a custom apparatus that exposes the PSS brushes to both tangential shear forces from the primary flow and upward drag forces from a secondary flow. Our experimental findings clearly show that shear forces have a significant impact on how the chains in PSS brushes are arranged. At low shear rates, the tangential shear force causes the chains to tilt, leading to brush contraction. In contrast, higher shear rates generate an upward shear force that stretches and expands the chains. By analysing electron density profiles obtained from X-ray reflectivity, we gain valuable insights into how the PSS brushes respond structurally, especially the role of the diffuse layer in this dynamic behaviour. Our results highlight the importance of the initial chain configuration, which is influenced by the solvent and cations present, in shaping how polymer brushes respond to shear flow. The strength of the salt bridge network also plays a crucial role in determining how easily the brushes can stretch, with stronger networks offering more resistance to stretching. Ultimately, our study aims to enhance our understanding of polymer physics at interfaces, with a particular focus on practical applications involving polymer brushes.
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Affiliation(s)
- Yijun Qiao
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Qiming He
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Hsin-Hsiang Huang
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
| | - Dean Mastropietro
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
| | - Zhang Jiang
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Matthew V Tirrell
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Wei Chen
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
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5
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Wu X, Barner-Kowollik C. Fluorescence-readout as a powerful macromolecular characterisation tool. Chem Sci 2023; 14:12815-12849. [PMID: 38023522 PMCID: PMC10664555 DOI: 10.1039/d3sc04052f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
The last few decades have witnessed significant progress in synthetic macromolecular chemistry, which can provide access to diverse macromolecules with varying structural complexities, topology and functionalities, bringing us closer to the aim of controlling soft matter material properties with molecular precision. To reach this goal, the development of advanced analytical techniques, allowing for micro-, molecular level and real-time investigation, is essential. Due to their appealing features, including high sensitivity, large contrast, fast and real-time response, as well as non-invasive characteristics, fluorescence-based techniques have emerged as a powerful tool for macromolecular characterisation to provide detailed information and give new and deep insights beyond those offered by commonly applied analytical methods. Herein, we critically examine how fluorescence phenomena, principles and techniques can be effectively exploited to characterise macromolecules and soft matter materials and to further unravel their constitution, by highlighting representative examples of recent advances across major areas of polymer and materials science, ranging from polymer molecular weight and conversion, architecture, conformation to polymer self-assembly to surfaces, gels and 3D printing. Finally, we discuss the opportunities for fluorescence-readout to further advance the development of macromolecules, leading to the design of polymers and soft matter materials with pre-determined and adaptable properties.
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Affiliation(s)
- Xingyu Wu
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia
| | - Christopher Barner-Kowollik
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
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6
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Besford QA, Uhlmann P, Fery A. Spatially Resolving Polymer Brush Conformation: Opportunities Ahead. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Quinn A. Besford
- Leibniz‐Institut für Polymerforschung e.V. Hohe Str. 6 01069 Dresden Germany
| | - Petra Uhlmann
- Leibniz‐Institut für Polymerforschung e.V. Hohe Str. 6 01069 Dresden Germany
| | - Andreas Fery
- Leibniz‐Institut für Polymerforschung e.V. Hohe Str. 6 01069 Dresden Germany
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7
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Qiao Y, Zhou H, Jiang Z, He Q, Gan S, Wang H, Wen S, de Pablo J, Liu Y, Tirrell MV, Chen W. An in situ shearing x-ray measurement system for exploring structures and dynamics at the solid-liquid interface. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:013908. [PMID: 32012592 DOI: 10.1063/1.5129819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/05/2020] [Indexed: 06/10/2023]
Abstract
Revealing interfacial structure and dynamics has been one of the essential thematic topics in material science and condensed matter physics. Synchrotron-based x-ray scattering techniques can deliver unique and insightful probing of interfacial structures and dynamics, in particular, in reflection geometries with higher surface and interfacial sensitivity than transmission geometries. We demonstrate the design and implementation of an in situ shearing x-ray measurement system, equipped with both inline parallel-plate and cone-and-plate shearing setups and operated at the advanced photon source at Argonne National Laboratory, to investigate the structures and dynamics of end-tethered polymers at the solid-liquid interface. With a precise lifting motor, a micrometer-scale gap can be produced by aligning two surfaces of a rotating upper shaft and a lower sample substrate. A torsional shear flow forms in the gap and applies tangential shear forces on the sample surface. The technical combination with nanoscale rheology and the utilization of in situ x-ray scattering allow us to gain fundamental insights into the complex dynamics in soft interfaces under shearing. In this work, we demonstrate the technical scope and experimental capability of the in situ shearing x-ray system through the measurements of charged polymers at both flat and curved interfaces upon shearing. Through the in situ shearing x-ray scattering experiments integrated with theoretical simulations, we aim to develop a detailed understanding of the short-range molecular structure and mesoscale ionic aggregate morphology, as well as ion transport and dynamics in soft interfaces, thereby providing fundamental insight into a long-standing challenge in ionic polymer brushes with a significant technological impact.
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Affiliation(s)
- Yijun Qiao
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Zhang Jiang
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Qiming He
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Shenglong Gan
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Hongdong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shizhu Wen
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Juan de Pablo
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Matthew V Tirrell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Wei Chen
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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8
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Welbourn R, Clarke S. New insights into the solid–liquid interface exploiting neutron reflectivity. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Delcea M, Helm CA. X-ray and Neutron Reflectometry of Thin Films at Liquid Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8519-8530. [PMID: 30901219 DOI: 10.1021/acs.langmuir.8b04315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the 1980s, Helmuth Möhwald studied lipid monolayers at the air/water interface to understand the thermodynamically characterized phases at the molecular level. In collaboration with Jens Als-Nielsen, X-ray reflectometry was used and further developed to determine the electron density profile perpendicular to the water surface. Using a slab model, parameters such as thickness and density of the individual molecular regions, as well as the roughness of the individual interfaces, were determined. Later, X-ray and neutron reflectometry helped to understand the coverage and conformation of anchored and adsorbed polymers. Nowadays, they resolve molecular properties in emerging topics such as liquid metals and ionic liquids. Much is still to be learned about buried interfaces (e.g., liquid/liquid interfaces). In this Article, a historical and theoretical background of X-ray reflectivity is given, recent developments of X-ray and neutron reflectometry for polymers at interfaces and thin layers are highlighted, and emerging research topics involving these techniques are emphasized.
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Affiliation(s)
- Mihaela Delcea
- Institute of Biochemistry , University of Greifswald , Felix-Hausdorff-Straße 4 , 17489 Greifswald , Germany
- ZIK HIKE- Zentrum für Innovationskompetenz , Humorale Immunreaktionen bei kardiovaskulären Erkrankungen , Fleischmannstraße 42 , 17489 Greifswald , Germany
| | - Christiane A Helm
- Institute of Physics , University of Greifswald , Felix-Hausdorff-Straße 4 , 17489 Greifswald , Germany
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10
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Korolkovas A, Prévost S, Kawecki M, Devishvili A, Adlmann FA, Gutfreund P, Wolff M. The viscoelastic signature underpinning polymer deformation under shear flow. SOFT MATTER 2019; 15:371-380. [PMID: 30519692 DOI: 10.1039/c8sm02255k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Entangled polymers are deformed by a strong shear flow. The shape of the polymer, called the form factor, is measured by small angle neutron scattering. However, the real-space molecular structure is not directly available from the reciprocal-space data, due to the phase problem. Instead, the data has to be fitted with a theoretical model of the molecule. We approximate the unknown structure using piecewise straight segments, from which we derive an analytical form factor. We fit it to our data on a semi-dilute entangled polystyrene solution under in situ shear flow. The character of the deformation is shown to lie between that of a single ideal chain (viscous) and a cross-linked network (elastic rubber). Furthermore, we use the fitted structure to estimate the mechanical stress, and find a fairly good agreement with rheology literature.
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Affiliation(s)
- Airidas Korolkovas
- Institut Laue-Langevin, 71 rue des Martyrs, 38000 Grenoble, France. and Department for Physics and Astronomy, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
| | - Sylvain Prévost
- Institut Laue-Langevin, 71 rue des Martyrs, 38000 Grenoble, France.
| | - Maciej Kawecki
- Department for Physics and Astronomy, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
| | - Anton Devishvili
- Institut Laue-Langevin, 71 rue des Martyrs, 38000 Grenoble, France. and Department for Physical Chemistry, Naturvetarvägen 14, 223 62 Lund, Sweden
| | - Franz A Adlmann
- Department for Physics and Astronomy, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
| | | | - Max Wolff
- Department for Physics and Astronomy, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
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11
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García NA, Barrat JL. Entanglement Reduction Induced by Geometrical Confinement in Polymer Thin Films. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01884] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Nicolás A. García
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France
| | - Jean-Louis Barrat
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France
- Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
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12
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Kirk J, Kröger M, Ilg P. Surface Disentanglement and Slip in a Polymer Melt: A Molecular Dynamics Study. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01865] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jack Kirk
- School of Mathematical, Physical and Computational Sciences, University of Reading, Reading RG6 6AX, U.K
| | - Martin Kröger
- Polymer Physics, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Patrick Ilg
- School of Mathematical, Physical and Computational Sciences, University of Reading, Reading RG6 6AX, U.K
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13
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Lopez-Mila B, Alves P, Riedel T, Dittrich B, Mergulhão F, Rodriguez-Emmenegger C. Effect of shear stress on the reduction of bacterial adhesion to antifouling polymers. BIOINSPIRATION & BIOMIMETICS 2018; 13:065001. [PMID: 30141414 DOI: 10.1088/1748-3190/aadcc2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, two antifouling polymer brushes were tested at different shear stress conditions to evaluate their performance in reducing the initial adhesion of Escherichia coli. Assays were performed using a parallel plate flow chamber and a shear stress range between 0.005 and 0.056 Pa. These shear stress values are found in different locations in the human body where biomedical devices are placed. The poly(MeOEGMA) and poly(HPMA) brushes were characterized and it was shown that they can reduce initial adhesion up to 90% when compared to glass. Importantly, the performance of these surfaces was not affected by the shear stress, which is an indication that they do not collapse under this shear stress range. The brushes displayed a similar behavior despite the differences in their chemical composition and surface energy. Both surfaces have shown ultra-low adsorption of macromolecules from the medium when tested with relevant biological fluids (urine and serum). This indicates that these surfaces can potentially be used in biomedical devices to reduce initial bacterial colonization and eventually reduce biofilm formation on these devices.
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Affiliation(s)
- Betina Lopez-Mila
- Department of Chemistry and Physics of Surfaces and Biointerfaces, Institute of Macromolecular Chemistry, ASCR, v.v.i., Heyrovsky Sq. 2, 16206 Prague, Czechia. Both authors equally contributed to this work
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14
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Korolkovas A. 5D Entanglement in Star Polymer Dynamics. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Airidas Korolkovas
- Department of Physics and Astronomy; Uppsala University; Lägerhyddsvägen 1 752 37 Uppsala Sweden
- Large Scale Structures Group; Institut Laue-Langevin; 71 rue des Martyrs 38000 Grenoble France
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15
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Korolkovas A, Gutfreund P, Wolff M. Dynamical structure of entangled polymers simulated under shear flow. J Chem Phys 2018; 149:074901. [PMID: 30134722 DOI: 10.1063/1.5035170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The non-linear response of entangled polymers to shear flow is complicated. Its current understanding is framed mainly as a rheological description in terms of the complex viscosity. However, the full picture requires an assessment of the dynamical structure of individual polymer chains which give rise to the macroscopic observables. Here we shed new light on this problem, using a computer simulation based on a blob model, extended to describe shear flow in polymer melts and semi-dilute solutions. We examine the diffusion and the intermediate scattering spectra during a steady shear flow. The relaxation dynamics are found to speed up along the flow direction, but slow down along the shear gradient direction. The third axis, vorticity, shows a slowdown at the short scale of a tube, but reaches a net speedup at the large scale of the chain radius of gyration.
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Affiliation(s)
| | | | - Max Wolff
- Division for Material Physics, Department for Physics and Astronomy, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
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16
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Hernández Velázquez J, Mejía-Rosales S, Gama Goicochea A. Nanorheology of poly - and monodispersed polymer brushes under oscillatory flow as models of epithelial cancerous and healthy cell brushes. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.09.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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