51
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Sasaki T. Polymer Dynamics: Bulk and Nanoconfined Polymers. Polymers (Basel) 2022; 14:polym14071271. [PMID: 35406145 PMCID: PMC9002963 DOI: 10.3390/polym14071271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 11/28/2022] Open
Affiliation(s)
- Takashi Sasaki
- Department of Materials Science and Engineering, University of Fukui, Fukui 910-8507, Japan
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52
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Jaeger TD, Simmons DS. Temperature dependence of aging dynamics in highly non-equilibrium model polymer glasses. J Chem Phys 2022; 156:114504. [DOI: 10.1063/5.0080717] [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
A central feature of the non-equilibrium glassy “state” is its tendency to age toward equilibrium, obeying signatures identified by Kovacs over 50 years ago. The origin of these signatures, their fate far from equilibrium and at high temperatures, and the underlying nature of the glassy “state” far from equilibrium remain unsettled. Here, we simulate physical aging of polymeric glasses, driven much farther from equilibrium and at much higher temperatures than possible in experimental melt-quenched glasses. While these glasses exhibit Kovacs’ signatures of glassy aging at sufficiently low temperatures, these signatures disappear above the onset TA of non-Arrhenius equilibrium dynamics, suggesting that TA demarcates an upper bound to genuinely glassy states. Aging times in glasses after temperature up-jumps are found to obey an Arrhenius law interpolating between equilibrium dynamics at TA and at the start of the temperature up-jump, providing a zero-parameter rule predicting their aging behavior and identifying another unrecognized centrality of TA to aging behavior. This differs qualitatively from behavior of our glasses produced by temperature down-jumps, which exhibit a fractional power law decoupling relation with equilibrium dynamics. While the Tool–Narayanaswamy–Moynihan model can predict the qualitative single-temperature behavior of these systems, we find that it fails to predict the disappearance of Kovacs signatures above TA and the temperature dependence of aging after large temperature up-jumps. These findings highlight a need for new theoretical insights into the aging behavior of glasses at ultra-high fictive temperatures and far from equilibrium.
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Affiliation(s)
- Tamara D. Jaeger
- Department of Polymer Engineering, The University of Akron, Akron, Ohio 44325, USA
| | - David S. Simmons
- Department of Chemical, Biological, and Materials Engineering, University of South Florida, Tampa, Florida 33620, USA
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53
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McKenzie I, Fujimoto D, Karner VL, Li R, MacFarlane WA, McFadden RML, Morris GD, Pearson MR, Raegen AN, Stachura M, Ticknor JO, Forrest JA. A β-NMR study of the depth, temperature, and molecular-weight dependence of secondary dynamics in polystyrene: Entropy–enthalpy compensation and dynamic gradients near the free surface. J Chem Phys 2022; 156:084903. [DOI: 10.1063/5.0081185] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigated the depth, temperature, and molecular-weight (MW) dependence of the γ-relaxation in polystyrene glasses using implanted 8Li+ and β-detected nuclear magnetic resonance. Measurements were performed on thin films with MW ranging from 1.1 to 641 kg/mol. The temperature dependence of the average 8Li spin–lattice relaxation time [Formula: see text] was measured near the free surface and in the bulk. Spin–lattice relaxation is caused by phenyl ring flips, which involve transitions between local minima over free-energy barriers with enthalpic and entropic contributions. We used transition state theory to model the temperature dependence of the γ-relaxation, and hence [Formula: see text]. There is no clear correlation of the average entropy of activation [Formula: see text] and enthalpy of activation [Formula: see text] with MW, but there is a clear correlation between [Formula: see text] and [Formula: see text], i.e., entropy–enthalpy compensation. This results in the average Gibbs energy of activation, [Formula: see text], being approximately independent of MW. Measurements of the temperature dependence of [Formula: see text] as a function of depth below the free surface indicate the inherent entropic barrier, i.e., the entropy of activation corresponding to [Formula: see text] = 0, has an exponential dependence on the distance from the free surface before reaching the bulk value. This results in [Formula: see text] near the free surface being lower than the bulk. Combining these observations results in a model where the average fluctuation rate of the γ-relaxation has a “double-exponential” depth dependence. This model can explain the depth dependence of [Formula: see text] in polystyrene films. The characteristic length of enhanced dynamics is ∼6 nm and approximately independent of MW near room temperature.
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Affiliation(s)
- Iain McKenzie
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Derek Fujimoto
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Victoria L. Karner
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ruohong Li
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - W. Andrew MacFarlane
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ryan M. L. McFadden
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | | | - Matthew R. Pearson
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - Adam N. Raegen
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | | | - John O. Ticknor
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - James A. Forrest
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
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54
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Phan AD. Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films. J Phys Chem B 2022; 126:1609-1614. [PMID: 35166111 DOI: 10.1021/acs.jpcb.1c08862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature (Tg) are calculated at different temperatures and vitrification criteria. Molecular dynamics is significantly slowed down near rough solid surfaces, and the dynamics at location far from the interfaces is sped up. In thick films, the mobility gradient normalized by the bulk value obeys the double-exponential form since interference effects between two surfaces are weak. Reducing the film thickness induces a strong dynamic coupling between two surfaces and flattens the relaxation gradient. The normalized gradient of the glass transition temperature is independent of vitrification time scale criterion and can be fitted by a superposition function as the films are not ultrathin. The local fragility is found to remain unchanged with location. This finding suggests that one can use Angell plots of bulk relaxation time and the Tg spatial gradient to characterize glassy dynamics in metallic glass films. Our computational results agree well with experimental data and simulation.
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Affiliation(s)
- Anh D Phan
- Faculty of Materials Science and Engineering, Computer Science, Artificial Intelligence Laboratory, Phenikaa Institute for Advanced Study, Phenikaa University, Hanoi 12116, Vietnam
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55
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Bai L, Luo P, Yang X, Xu J, Kawaguchi D, Zhang C, Yamada NL, Tanaka K, Zhang W, Wang X. Enhanced Glass Transition Temperature of Thin Polystyrene Films Having an Underneath Cross-Linked Layer. ACS Macro Lett 2022; 11:210-216. [PMID: 35574771 DOI: 10.1021/acsmacrolett.1c00611] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Due to the importance of the interface in the segmental dynamics of supported macromolecule ultrathin films, the glass transition temperature (Tg) of polystyrene (PS) ultrathin films upon solid substrates modified with a cross-linked PS (CLPS) layer has been investigated. The results showed that the Tg of the thin PS films on a silica surface with a ∼5 nm cross-linked layer increased with reducing film thickness. Meanwhile, the increase in Tg of the thin PS films became more pronounced with increasing the cross-linking density of the layer. For example, a 20 nm thick PS film supported on CLPS with 1.8 kDa of cross-linking degree exhibited a ∼35 and ∼50 K increase in Tg compared to its bulk and that on neat SiO2 substrate, respectively. Such a large Tg elevation for the ultrathin PS films was attributed to the interfacial aggregation states in which chains diffused through nanolevel voids formed in the cross-linked layer to the SiO2-Si surface. In such a situation, the chains were topologically constrained in the cross-linked layer with less mobility. These results offer us the opportunity to tailor interfacial effects by changing the degree of cross-linking, which has great potential application in many polymer nanocomposites.
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Affiliation(s)
- Lu Bai
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Pan Luo
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xudong Yang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jianquan Xu
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Daisuke Kawaguchi
- Department of Applied Chemistry and Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Cuiyun Zhang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Norifumi L. Yamada
- Neutron Science Division, Institute for Materials Structure Science, High Energy, Acceleration Research Organization, Naka, Ibaraki 319-1106, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry and Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Wei Zhang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
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56
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Enhancing mechanical and interfacial properties of PEEK/epoxy/SWCNT composites employing aromatic hydroxyl and amine-functionalized SWCNTs. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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57
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Brick D, Hofstetter M, Stritt P, Rinder J, Gusev V, Dekorsy T, Hettich M. Glass transition of nanometric polymer films probed by picosecond ultrasonics. ULTRASONICS 2022; 119:106630. [PMID: 34735929 DOI: 10.1016/j.ultras.2021.106630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 08/14/2021] [Accepted: 10/17/2021] [Indexed: 06/13/2023]
Abstract
The possibility to measure the glass transition temperature in poly(methyl methacrylate) (PMMA) films by picosecond ultrasonics with thicknesses ranging from 458 nm to 32 nm is demonstrated. A shift of the longitudinal acoustic eigenmodes towards lower frequencies with temperature is observed accompanied by a change in the temperature-frequency slopes at the glass transition temperature. The contributions to the frequency shift from changes in film thickness and sound velocity are discussed and the latter is extracted below the glass transition temperature. Finally, the advantages and disadvantages of the current approach in a comparison to other methods based on acoustic measurements in the GHz regime are reviewed.
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Affiliation(s)
- D Brick
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - M Hofstetter
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - P Stritt
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - J Rinder
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - V Gusev
- Laboratoire d'Acoustique de l'Université du Mans (LAUM), UMR 6613, Institut d'Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, Av. O. Messiaen, 72085 Le Mans, France
| | - T Dekorsy
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany; Institute of Technical Physics, German Aerospace Center, Pfaffenwaldring 38-40, 70569 Stuttgart, Germany
| | - M Hettich
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany; Research Center for Non-Destructive Testing GmbH, Altenbergerstr. 96, 4040 Linz, Austria..
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58
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Audureau N, Coumes F, Rieger J, Stoffelbach F. Poly(N-cyanoethylacrylamide), a new thermoresponsive homopolymer presenting both LCST and UCST behavior in water. Polym Chem 2022. [DOI: 10.1039/d2py00032f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have recently demonstrated that poly(N-cyanomethylacrylamide) (PCMAm) synthesized by reversible addition-fragmentation chain transfer (RAFT) radical polymerization exhibits a typical upper critical solution temperature (UCST)-type transition in water with a very...
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59
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Richard I, Maurya AK, Shadman S, Masquelier E, Marthey LS, Neels A, Sorin F. Unraveling the Influence of Thermal Drawing Parameters on the Microstructure and Thermo-Mechanical Properties of Multimaterial Fibers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2101392. [PMID: 34761869 DOI: 10.1002/smll.202101392] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/02/2021] [Indexed: 06/13/2023]
Abstract
Multimaterial thermally drawn fibers are becoming important building blocks in several foreseen applications in surgical probes, protective gears, or medical textiles. Here, the influence of the thermal drawing parameters on the degree of polymer chain orientation, the related thermal shrinkage behavior, and the mechanical properties of the final fibers is investigated via thermo-mechanical testing and small- and wide-angle X-ray scattering (SAXS and WAXS) analyses. This study on polyetherimide fibers reveals that the drawing stress, which depends on the drawing speed and temperature, controls the thermal shrinkage behavior and mechanical properties. Furthermore, SAXS and WAXS analyses show that the degree of chain orientation increases with drawing stresses below 8 MPa and then saturates, which correlates with the amount of observed shrinkage. The use of this process-dependent polymer chain alignment to tune the mechanical and shrinkage properties of the fibers is highlighted and controlled bending multimaterial fibers made of two polymethyl methacrylates having different molecular weights are developed. Finally, a heat treatment procedure is proposed to relax the chain alignment and increase the dimensional stability of devices such as temperature sensors. This deeper understanding can serve as a guide for the processing of complex fibers requiring specific mechanical properties or enhanced thermal stability.
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Affiliation(s)
- Inès Richard
- Laboratory of Photonic Materials and Fibre Devices (FIMAP), Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Anjani K Maurya
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics, St. Gallen, CH-9014, Switzerland
- ARTORG Center for Biomedical Engineering Research, University of Bern, Murtenstrasse 50, Bern, 3008, Switzerland
| | - Shahrzad Shadman
- Laboratory of Photonic Materials and Fibre Devices (FIMAP), Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Eloïse Masquelier
- Laboratory of Photonic Materials and Fibre Devices (FIMAP), Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Lison S Marthey
- Laboratory of Photonic Materials and Fibre Devices (FIMAP), Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Antonia Neels
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics, St. Gallen, CH-9014, Switzerland
- Department of Chemistry, University of Fribourg, Chemin du Musée 9, Fribourg, 1700, Switzerland
| | - Fabien Sorin
- Laboratory of Photonic Materials and Fibre Devices (FIMAP), Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
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60
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Zhao† Z, Deng† S, Wang Q, Jia C, Yang J. Novel Insight into Blocking Cancer Metastasis by Biological Nano Confinement through Altering the Cancer Microenvironment. CLINICAL CANCER INVESTIGATION JOURNAL 2022. [DOI: 10.51847/0ozasxscb1] [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]
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61
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Kardasis P, Oikonomopoulos A, Sakellariou G, Steinhart M, Floudas G. Effect of Star Architecture on the Dynamics of 1,4- cis-Polyisoprene under Nanometer Confinement. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c02212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Angelos Oikonomopoulos
- Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Georgios Sakellariou
- Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Martin Steinhart
- Institut für Chemie neuer Materialien, Universität Osnabrück, Osnabrück D-49069, Germany
| | - George Floudas
- Department of Physics, University of Ioannina, Ioannina 45110, Greece
- Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), Ioannina 45110, Greece
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62
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Lei Q, He F, Zhao X, Yin J. Inorganic reinforced poly(ionic liquid) microcapsules: confined cooling-assisted phase separation self-assembly and enhanced electro-responsive property. Macromol Rapid Commun 2021; 43:e2100769. [PMID: 34932252 DOI: 10.1002/marc.202100769] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/15/2021] [Indexed: 11/08/2022]
Abstract
We report a simple preparation of inorganic reinforced poly(ionic liquid) (PIL) microcapsules by combining dispersion polymerization and confined cooling-assisted phase separation self-assembly. Silane coupling agent-modified PIL microbeads were first prepared by dispersion polymerization. Then, the microbeads were dissolved in a mixed solvent composed of good solvent and non-solvent to form hollow SiOx microcapsules at a relatively high temperature. Finally, the solution was cooled to induce the nucleation and growth of dissolved PIL chains on the inner and outer surface of hollow SiOx microcapsules to form inorganic reinforced microcapsules with asymmetric PIL/SiOx /PIL sandwich-like shell. The morphology of microcapsules can be controlled by adjusting PIL concentration and cooling rate. The inorganic reinforced microcapsules show enhanced suspended stability and electro-responsive characteristic when used as the dispersed phase of smart suspensions. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Qi Lei
- Smart Materials Laboratory, Department of Applied Physics, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, Shaanxi, 710129, China.,Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, 518057, China
| | - Fang He
- Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, 518057, China
| | - Xiaopeng Zhao
- Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, 518057, China
| | - Jianbo Yin
- Smart Materials Laboratory, Department of Applied Physics, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, Shaanxi, 710129, China.,Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, Guangdong, 518057, China
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63
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Lairenjam PD, Sukumaran SK, Satapathy DK. Modulation of Optical Anisotropy in Chitosan Thin Films: Role of Swelling. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pradipkanti Devi Lairenjam
- Soft Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Molecular Electronics Laboratory, Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Sathish K. Sukumaran
- Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan
| | - Dillip K. Satapathy
- Soft Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
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64
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Liu J, Liu G, Song Z, Kaltenegger M, Silva de Moraes L, Gopi E, Napolitano S, Geerts YH. Memory Effect and Crystallization of ( R, S)-2-Chloromandelic Acid Glass. J Phys Chem B 2021; 125:13339-13347. [PMID: 34808063 DOI: 10.1021/acs.jpcb.1c07749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
(R, S)-2-Chloromandelic acid, which can crystallize in racemic crystals (forms α and β) or a conglomerate (form γ), has been studied for its glass-forming behavior. Below the glass transition temperature, samples of the title compound crack into pieces. Correlation plots of DSC results have been used to investigate what determines the cracking and its occurrence temperature. We found that the latter is influenced by the polymorph from which the melt state has been obtained, showing that a certain memory of the previous crystalline phase persists in the undercooled melt. Moreover, this residual structure could be eliminated by elongating the annealing period or increasing the annealing temperature. Investigation using broadband dielectric spectroscopy confirmed such a memory effect. Finally, we studied the role of cracking in the control of the crystallization. In contrast with previous literature on other glass-forming molecular systems, we verified that the crystallization upon reheating is not impacted by the occurrence of cracks in the glassy state. This observation challenges the current views on polymorphic crystallization from organic glasses.
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Affiliation(s)
- Jie Liu
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Guangfeng Liu
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Zijian Song
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Martin Kaltenegger
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium.,Institute for Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria
| | - Lygia Silva de Moraes
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium.,Instituto de Física, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, 21941909 Rio de Janeiro, Brazil
| | - Elumalai Gopi
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Simone Napolitano
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Yves Henri Geerts
- Laboratoire de Chimie des Polymères, Faculté des Sciences, Université Libre de Bruxelles (ULB), CP 206/1, Boulevard du Triomphe, 1050 Brussels, Belgium.,International Solvay Institutes of Physics and Chemistry, ULB-Campus Plaine-CP 231, Boulevard du Triomphe, 1050 Brussels, Belgium
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65
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Li Z, Guo F, Pang K, Lin J, Gao Q, Chen Y, Chang D, Wang Y, Liu S, Han Y, Liu Y, Xu Z, Gao C. Precise Thermoplastic Processing of Graphene Oxide Layered Solid by Polymer Intercalation. NANO-MICRO LETTERS 2021; 14:12. [PMID: 34862936 PMCID: PMC8643290 DOI: 10.1007/s40820-021-00755-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/18/2021] [Indexed: 05/16/2023]
Abstract
The processing capability is vital for the wide applications of materials to forge structures as-demand. Graphene-based macroscopic materials have shown excellent mechanical and functional properties. However, different from usual polymers and metals, graphene solids exhibit limited deformability and processibility for precise forming. Here, we present a precise thermoplastic forming of graphene materials by polymer intercalation from graphene oxide (GO) precursor. The intercalated polymer enables the thermoplasticity of GO solids by thermally activated motion of polymer chains. We detect a critical minimum containing of intercalated polymer that can expand the interlayer spacing exceeding 1.4 nm to activate thermoplasticity, which becomes the criteria for thermal plastic forming of GO solids. By thermoplastic forming, the flat GO-composite films are forged to Gaussian curved shapes and imprinted to have surface relief patterns with size precision down to 360 nm. The plastic-formed structures maintain the structural integration with outstanding electrical (3.07 × 105 S m-1) and thermal conductivity (745.65 W m-1 K-1) after removal of polymers. The thermoplastic strategy greatly extends the forming capability of GO materials and other layered materials and promises versatile structural designs for more broad applications.
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Affiliation(s)
- Zeshen Li
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Fan Guo
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China.
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, 1 Guanghua Road, Nanjing, 210094, People's Republic of China.
| | - Kai Pang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Jiahao Lin
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Qiang Gao
- School of Mechanical Engineering, Southeast University, Nanjing, 211189, People's Republic of China
| | - Yance Chen
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Dan Chang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Ya Wang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Senping Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Yi Han
- Hangzhou Gaoxi Technology Co. Ltd, Yuhang District, Liangzhu, 311113, People's Republic of China
| | - Yingjun Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China
| | - Zhen Xu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China.
| | - Chao Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, People's Republic of China.
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66
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Winkler R, Tu W, Dulski M, Laskowski L, Adrjanowicz K. Effect of the Surface Polarity, Through Employing Nonpolar Spacer Groups, on the Glass-Transition Dynamics of Poly(phenyl methylsiloxane) Confined in Alumina Nanopores. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c02145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Roksana Winkler
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, Chorzow 41-500, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1, Chorzow 41-500, Poland
| | - Wenkang Tu
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, Chorzow 41-500, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1, Chorzow 41-500, Poland
| | - Mateusz Dulski
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1, Chorzow 41-500, Poland
- Institute of Materials Engineering, University of Silesia, 75 Pulku Piechoty 1a, Chorzow 41-500, Poland
| | - Lukasz Laskowski
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow 31-342, Poland
| | - Karolina Adrjanowicz
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, Chorzow 41-500, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1, Chorzow 41-500, Poland
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67
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Murali A, Ganesan M, Satapathy DK, Kumar PBS. Penetrant-Induced Glass-like Transition in Thin Chitosan Films. J Phys Chem B 2021; 125:12617-12626. [PMID: 34730977 DOI: 10.1021/acs.jpcb.1c07903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the water vapor-induced swelling and the emergence of a penetrant-induced glass-like transition in the substrate-supported glassy chitosan thin films. The time evolution of the film thickness under different levels of relative humidity conditions is measured in real-time using a spectroscopic ellipsometer equipped with a humidity cell. In a dry film, the network of chitosan chains is in a glassy state, and upon exposure to water vapor, initially, the film swells by Fickian diffusion of water molecules, which triggers the structural relaxations of the chains. Under higher humidity conditions, a relatively slower evolution of thickness succeeds the initial rapid swelling due to the non-Fickian sorption of water molecules. The swelling characteristics of the polymer films are accounted for by considering the diffusion-relaxation mechanism of chains in the presence of smaller penetrant molecules. The penetrant-induced glass-like transition (Pg), where the polymer film isothermally transits from a glassy to a rubbery state, is determined for pristine and cross-linked chitosan films. Pg is determined from the abrupt change in the rate of swelling observed upon increasing the relative humidity. Chemical crosslinking has an evident influence on the penetrant-induced glass-like transition of the chitosan films. Pg was found to rise sharply for stiffer films with higher cross-linking density.
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Affiliation(s)
- Aathira Murali
- Department of Physics, Indian Institute of Technology Palakkad, Kanjikode, Kerala 678623, India
| | - Manikandan Ganesan
- Soft Materials Laboratory, Department of Physics and Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Dillip K Satapathy
- Soft Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - P B Sunil Kumar
- Department of Physics, Indian Institute of Technology Palakkad, Kanjikode, Kerala 678623, India
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68
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Influence of the Filler Particles' Surface Morphology on the Polyurethane Matrix's Structure Formation in the Composite. Polymers (Basel) 2021; 13:polym13223864. [PMID: 34833164 PMCID: PMC8624056 DOI: 10.3390/polym13223864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 12/03/2022] Open
Abstract
This article presents the surface morphology effect of silicon carbide (SiC) particles on the polyurethane binder’s structure formation in a dispersed-filled composite. The difference in the morphology and surface relief of filler particles was ensured by the implementation of plasma chemical modification. As a result of this modification, the filler consisted of core-shell particles characterized by a SiC core and a carbon shell (SiC@C), as well as a carbon shell decorated with silicon nanoparticles (SiC@C/SiNP) or nanos (SiC@C/SiNW). The study of the relaxation properties of polyurethane composites has shown that the strongest limiting effect on the molecular mobility of boundary layer’s chain segments is exerted by a highly developed surface with a complex relief of SiC@C/SiNP and SiC@C/SiNW particles. An empirical method was proposed to find the polymer fractions spent on the formation of the boundary, transition and bulk layers of the polymer matrix in the composite. It was shown that the morphology of the filler particles’ surface does not affect the dependence of the boundary layer thickness on the filler’s volume fraction. However, with an increase in the degree of surface development, the boundary layer thickness decreases.
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69
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Zhang W, Starr FW, Douglas JF. Activation free energy gradient controls interfacial mobility gradient in thin polymer films. J Chem Phys 2021; 155:174901. [PMID: 34742183 DOI: 10.1063/5.0064866] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We examine the mobility gradient in the interfacial region of substrate-supported polymer films using molecular dynamics simulations and interpret these gradients within the string model of glass-formation. No large gradients in the extent of collective motion exist in these simulated films, and an analysis of the mobility gradient on a layer-by-layer basis indicates that the string model provides a quantitative description of the relaxation time gradient. Consequently, the string model indicates that the interfacial mobility gradient derives mainly from a gradient in the high-temperature activation enthalpy ΔH0 and entropy ΔS0 as a function of depth z, an effect that exists even in the high-temperature Arrhenius relaxation regime far above the glass transition temperature. To gain insight into the interfacial mobility gradient, we examined various material properties suggested previously to influence ΔH0 in condensed materials, including density, potential and cohesive energy density, and a local measure of stiffness or u2(z)-3/2, where u2(z) is the average mean squared particle displacement at a caging time (on the order of a ps). We find that changes in local stiffness best correlate with changes in ΔH0(z) and that ΔS0(z) also contributes significantly to the interfacial mobility gradient, so it must not be neglected.
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Affiliation(s)
- Wengang Zhang
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Francis W Starr
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
| | - Jack F Douglas
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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70
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White RP, Lipson JEG. The dynamics of freestanding films: predictions for poly(2-chlorostyrene) based on bulk pressure dependence and thoughtful sample averaging. SOFT MATTER 2021; 17:9755-9764. [PMID: 34647951 DOI: 10.1039/d1sm01175h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this paper we model the segmental relaxation in poly(2-chlorostyrene) 18 nm freestanding films, using only data on bulk samples to characterize the system, and predict film relaxation times (τ) as a function of temperature that are in semi-quantitative agreement with film data. The ability to translate bulk characterization into film predictions is a direct result of our previous work connecting the effects of free surfaces in films with those of changing pressure in the bulk. Our approach combines the Locally Correlated Lattice (LCL) equation of state for prediction of free volume values (Vfree) at any given density (ρ), which are then used in the Cooperative Free Volume (CFV) rate model to predict τ(T, Vfree). A key feature of this work is that we calculate the locally averaged density profile as a function of distance from the surface, ρav(z), using the CFV-predicted lengthscale, Lcoop(z), over which rearranging molecular segments cooperate. As we have shown in the past, ρav(z) is significantly broader than the localized profile, ρ(z), which translates into a relaxation profile, τ(z), exhibiting a breadth that mirrors experimental and simulated results. In addition, we discuss the importance of averaging the log of position dependent relaxation times across a film sample (〈log τ(z)〉), as opposed to averaging the relaxation times, themselves, in order to best approximate a whole sample-averaged value that can be directly compared to experiment.
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Affiliation(s)
- Ronald P White
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
| | - Jane E G Lipson
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
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71
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Sasaki T, Tsuzuki Y, Nakane T. A Dynamically Correlated Network Model for the Collective Dynamics in Glass-Forming Molecular Liquids and Polymers. Polymers (Basel) 2021; 13:3424. [PMID: 34641239 PMCID: PMC8512962 DOI: 10.3390/polym13193424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/02/2021] [Accepted: 10/03/2021] [Indexed: 11/23/2022] Open
Abstract
The non-Arrhenius behavior of segmental dynamics in glass-forming liquids is one of the most profound mysteries in soft matter physics. In this article, we propose a dynamically correlated network (DCN) model to understand the growing behavior of dynamically correlated regions during cooling, which leads to the viscous slowdown of supercooled liquids. The fundamental concept of the model is that the cooperative region of collective motions has a network structure that consists of string-like parts, and networks of various sizes interpenetrate each other. Each segment undergoes dynamical coupling with its neighboring segments via a finite binding energy. Monte Carlo simulations showed that the fractal dimension of the DCNs generated at different temperatures increased and their size distribution became broader with decreasing temperature. The segmental relaxation time was evaluated based on a power law with four different exponents for the activation energy of rearrangement with respect to the DCN size. The results of the present DCN model are consistent with the experimental results for various materials of molecular and polymeric liquids.
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Affiliation(s)
- Takashi Sasaki
- Department of Materials Science and Engineering, University of Fukui, Fukui 9108507, Japan; (Y.T.); (T.N.)
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72
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Li W, Olvera de la Cruz M. Glass transition of ion-containing polymer melts in bulk and thin films. SOFT MATTER 2021; 17:8420-8433. [PMID: 34542131 DOI: 10.1039/d1sm01098k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ion-containing polymers often are good glass formers, and the glass transition temperature is an important parameter to consider for practical applications, which prescribes the working temperature range for different mechanical and dynamic properties. In this work, we present a systematic molecular dynamics simulation study on the coupling of ionic correlations with the glass transition, based on a generic coarse-grained model of ionic polymers. The variation of the glass transition temperature is examined concerning the influence of the electrostatic interaction strength, charge fraction, and charge sequence. The interplay with the film thickness effect is also discussed. Our results reveal a few typical features about the glass transition process that are in qualitative agreement with previous studies, further highlighting the effects of counterion entropy at weak ionic correlations and physical crosslinking of ionic aggregates at strong ionic correlations. Detailed parametric dependencies are displayed, which demonstrate that introducing strong ionic correlations promotes vitrification while adopting a precise charge sequence and applying strong confinement with weak surface affinity reduce the glass transition temperature. Overall, our investigation provides an improved picture towards a comprehensive understanding of the glass transition in ion-containing polymeric systems from a molecular simulation perspective.
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Affiliation(s)
- Wei Li
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
| | - Monica Olvera de la Cruz
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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73
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Chat K, Tu W, Beena Unni A, Adrjanowicz K. Influence of Tacticity on the Glass-Transition Dynamics of Poly(methyl methacrylate) (PMMA) under Elevated Pressure and Geometrical Nanoconfinement. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Katarzyna Chat
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Wenkang Tu
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Aparna Beena Unni
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Karolina Adrjanowicz
- Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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74
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Relaxation behavior of polymer thin films: Effects of free surface, buried interface, and geometrical confinement. Prog Polym Sci 2021. [DOI: 10.1016/j.progpolymsci.2021.101431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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75
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Smaranda I, Nila A, Ganea P, Daescu M, Zgura I, Ciobanu RC, Trandabat A, Baibarac M. The Influence of the Ceramic Nanoparticles on the Thermoplastic Polymers Matrix: Their Structural, Optical, and Conductive Properties. Polymers (Basel) 2021; 13:polym13162773. [PMID: 34451312 PMCID: PMC8402000 DOI: 10.3390/polym13162773] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
This paper prepared composites under the free membranes form that are based on thermoplastic polymers of the type of polyurethane (TPU) and polyolefin (TPO), which are blended in the weight ratio of 2:1, and ceramic nanoparticles (CNs) such as BaSrTiO3 and SrTiO3. The structural, optical, and conductive properties of these new composite materials are reported. The X-ray diffraction studies highlight a cubic crystalline structure of these CNs. The main variations in the vibrational properties of the TPU:TPO blend induced by CNs consist of the following: (i) the increase in the intensity of the Raman line of 1616 cm-1; (ii) the down-shift of the IR band from 800 to 791 cm-1; (iii) the change of the ratio between the absorbance of IR bands localized in the spectral range 950-1200 cm-1; and (iv) the decrease in the absorbance of the IR band from 1221 cm-1. All these variations were correlated with a preferential adsorption of thermoplastic polymers on the CNs surface. A photoluminescence (PL) quenching process of thermoplastic polymers is demonstrated to occur in the presence of CNs. The anisotropic PL measurements have highlighted a change in the angle of the binding of the TPU:TPO blend, which varies from 23.7° to ≈49.3° and ≈53.4°, when the concentration of BaSrTiO3 and SrTiO3 CNs, respectively, is changed from 0 to 25 wt. %. Using dielectric spectroscopy, two mechanisms are invoked to take place in the case of the composites based on TPU:TPO blends and CNs, i.e., one regarding the type of the electrical conduction and another specifying the dielectric-dipolar relaxation processes.
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Affiliation(s)
- Ion Smaranda
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
| | - Andreea Nila
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
| | - Paul Ganea
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
| | - Monica Daescu
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
| | - Irina Zgura
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
| | - Romeo C. Ciobanu
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering, Technical University Gh. Asachi Iasi, Boulevard Profesor Dimitrie Mangeron 67, R070050 Iasi, Romania; (R.C.C.); (A.T.)
| | - Alexandru Trandabat
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering, Technical University Gh. Asachi Iasi, Boulevard Profesor Dimitrie Mangeron 67, R070050 Iasi, Romania; (R.C.C.); (A.T.)
| | - Mihaela Baibarac
- Laboratory Optical Processes in Nanostructured Materials, National Institute of Materials Physics, Atomistilor Street 405A, R077125 Bucharest, Romania; (I.S.); (A.N.); (P.G.); (M.D.); (I.Z.)
- Correspondence: ; Tel.: + 40-21-3690170
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76
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Hao Z, Ghanekarade A, Zhu N, Randazzo K, Kawaguchi D, Tanaka K, Wang X, Simmons DS, Priestley RD, Zuo B. Mobility gradients yield rubbery surfaces on top of polymer glasses. Nature 2021; 596:372-376. [PMID: 34408328 DOI: 10.1038/s41586-021-03733-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 06/15/2021] [Indexed: 02/07/2023]
Abstract
Many emerging materials, such as ultrastable glasses1,2 of interest for phone displays and OLED television screens, owe their properties to a gradient of enhanced mobility at the surface of glass-forming liquids. The discovery of this surface mobility enhancement3-5 has reshaped our understanding of the behaviour of glass formers and of how to fashion them into improved materials. In polymeric glasses, these interfacial modifications are complicated by the existence of a second length scale-the size of the polymer chain-as well as the length scale of the interfacial mobility gradient6-9. Here we present simulations, theory and time-resolved surface nano-creep experiments to reveal that this two-scale nature of glassy polymer surfaces drives the emergence of a transient rubbery, entangled-like surface behaviour even in polymers comprised of short, subentangled chains. We find that this effect emerges from superposed gradients in segmental dynamics and chain conformational statistics. The lifetime of this rubbery behaviour, which will have broad implications in constraining surface relaxations central to applications including tribology, adhesion, and surface healing of polymeric glasses, extends as the material is cooled. The surface layers suffer a general breakdown in time-temperature superposition (TTS), a fundamental tenet of polymer physics and rheology. This finding may require a reevaluation of strategies for the prediction of long-time properties in polymeric glasses with high interfacial areas. We expect that this interfacial transient elastomer effect and TTS breakdown should normally occur in macromolecular systems ranging from nanocomposites to thin films, where interfaces dominate material properties5,10.
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Affiliation(s)
- Zhiwei Hao
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - Asieh Ghanekarade
- Department of Chemical, Biological, and Materials Engineering, University of South Florida, Tampa, FL, USA
| | - Ningtao Zhu
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - Katelyn Randazzo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - Daisuke Kawaguchi
- Department of Applied Chemistry, Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Center for Polymer Interface and Molecular Adhesion Science, Kyushu University, Fukuoka, Japan
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China
| | - David S Simmons
- Department of Chemical, Biological, and Materials Engineering, University of South Florida, Tampa, FL, USA.
| | - Rodney D Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA. .,Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, NJ, USA.
| | - Biao Zuo
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, China.
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77
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Collinson DW, Sheridan RJ, Palmeri MJ, Brinson LC. Best practices and recommendations for accurate nanomechanical characterization of heterogeneous polymer systems with atomic force microscopy. Prog Polym Sci 2021. [DOI: 10.1016/j.progpolymsci.2021.101420] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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78
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Gawek M, Madkour S, Szymoniak P, Radnik J, Schönhals A. Energy dependent XPS measurements on thin films of a poly(vinyl methyl ether)/polystyrene blend concentration profile on a nanometer resolution to understand the behavior of nanofilms. SOFT MATTER 2021; 17:6985-6994. [PMID: 34236377 DOI: 10.1039/d1sm00656h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The composition of the surface layer in dependence from the distance of the polymer/air interface in thin films with thicknesses below 100 nm of miscible polymer blends in a spatial region of a few nanometers is not investigated completely. Here, thin films of the blend poly(vinyl methyl ether) (PVME)/polystyrene (PS) with a composition of 25/75 wt% are investigated by Energy Resolved X-ray Photoelectron Spectroscopy (ER-XPS) at a synchrotron storage ring using excitation energies lower than 1 keV. By changing the energy of the photons the information depth is varied in the range from ca. 1 nm to 10 nm. Therefore, the PVME concentration could be estimated in dependence from the distance of the polymer/air interface for film thicknesses below 100 nm. Firstly, as expected for increasing information depth the PVME concentration decreases. Secondly, it was found that the PVME concentration at the surface has a complicated dependence on the film thickness. It increases with decreasing film thickness until 30 nm where a maximum is reached. For smaller film thicknesses the PVME concentration decreases. A simplified layer model is used to calculate the effective PVME concentration in the different spatial regions of the surface layer.
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Affiliation(s)
- Marcel Gawek
- Bundesanstalt für Materialforschung und - prüfung (BAM) (Fachbereich 6.6), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Sherif Madkour
- Bundesanstalt für Materialforschung und - prüfung (BAM) (Fachbereich 6.6), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Paulina Szymoniak
- Bundesanstalt für Materialforschung und - prüfung (BAM) (Fachbereich 6.6), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Jörg Radnik
- Bundesanstalt für Materialforschung und - prüfung (BAM) (Fachbereich 6.6), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Andreas Schönhals
- Bundesanstalt für Materialforschung und - prüfung (BAM) (Fachbereich 6.6), Unter den Eichen 87, 12205 Berlin, Germany.
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79
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Corbisieri C, Jousset P, Roos M. The glass transition of amorphous polymers: About a continuous equation of state and its derivatives. J Appl Polym Sci 2021. [DOI: 10.1002/app.50662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Claudio Corbisieri
- Institute for Materials Technology and Plastics Processing Eastern Switzerland University of Applied Sciences Rapperswil‐Jona Switzerland
| | - Pierre Jousset
- Institute for Materials Technology and Plastics Processing Eastern Switzerland University of Applied Sciences Rapperswil‐Jona Switzerland
| | - Markus Roos
- Institute of Computational Physics Zurich University of Applied Sciences Winterthur Switzerland
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80
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Giermanska J, Ben Jabrallah S, Delorme N, Vignaud G, Chapel JP. Direct experimental evidences of the density variation of ultrathin polymer films with thickness. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123934] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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81
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Nguyen HK, Goseki R, Ishizone T, Nakajima K. Effect of molecular weight and architecture on nanoscale viscoelastic heterogeneity at the surface of polymer films. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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82
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Harmanli I, Tarakina NV, Antonietti M, Oschatz M. "Giant" Nitrogen Uptake in Ionic Liquids Confined in Carbon Pores. J Am Chem Soc 2021; 143:9377-9384. [PMID: 34128662 PMCID: PMC8251693 DOI: 10.1021/jacs.1c00783] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Ionic liquids are
well known for their high gas absorption capacity.
It is shown that this is not a solvent constant, but can be enhanced
by another factor of 10 by pore confinement, here of the ionic liquid
(IL) 1-ethyl-3-methylimidazolium acetate (EmimOAc) in the pores of
carbon materials. A matrix of four different carbon compounds with
micro- and mesopores as well as with and without nitrogen doping is
utilized to investigate the influence of the carbons structure on
the nitrogen uptake in the pore-confined EmimOAc. In general, the
absorption is most improved for IL in micropores and in nitrogen-doped
carbon. This effect is so large that it is already seen in TGA and
DSC experiments. Due to the low vapor pressure of the IL, standard
volumetric sorption experiments can be used to quantify details of
this effect. It is reasoned that it is the change of the molecular
arrangement of the ions in the restricted space of the pores that
creates additional free volume to host molecular nitrogen.
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Affiliation(s)
- Ipek Harmanli
- Department of Colloid Chemistry, Research Campus Golm, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.,Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
| | - Nadezda V Tarakina
- Department of Colloid Chemistry, Research Campus Golm, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Markus Antonietti
- Department of Colloid Chemistry, Research Campus Golm, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Martin Oschatz
- Department of Colloid Chemistry, Research Campus Golm, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany.,Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
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83
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Bhatt S, Bagchi D. Molecular and micro-scale heterogeneities in Raman modes of a relaxing polymer glass. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:325101. [PMID: 34062521 DOI: 10.1088/1361-648x/ac06ec] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
We have used Raman spectroscopy to study relaxation dynamics at two different length scales, molecular level and micro-scale in order to probe the presence of cooperative rearranging regions in a polymer glass. Response to slow thermal cycles and fast quench through the glass transition temperature (Tg) is analyzed for film and unprocessed forms of polyvinyl acetate (PVAc). In PVAc film, enhanced disorder and molecular mobility lead to peak broadening by about a factor of 10 compared to unprocessed PVAc. Thermal cycles (10 K min-1) produce hysteresis in integrated Raman peak intensity (loop areaAINTI).AINTIvalues of film are two orders of magnitude more than unprocessed, indicating more configurational mosaics with higher interfacial energy dissipations. Ageing after 60 K min-1quench manifests as heterogeneous molecular dynamics of film Raman modes with significant peak-width variations, differentiating high mobility and low mobility modes. Two-dimensional mapping of film Raman modes after quench reveal micro-scale clusters of average size ≈250 molecules having fractal boundaries with fractal dimensiondf= 1.5, resemblingdfof percolation clusters below percolation threshold. During thermal cycling and relaxation after a quench, cooperative segmental dynamics with large correlations between skeletal C-C stretch and side branch modes is observed. The observations are analyzed in the context of the random first order transition theory of glasses, which attributes heterogeneous relaxations in glasses to the presence of clusters of variable configurational states.
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Affiliation(s)
- Shipra Bhatt
- Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390002, Gujarat, India
| | - Debjani Bagchi
- Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390002, Gujarat, India
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84
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Bonnaud PA, Ushiyama H, Tejima S, Fujita JI. Neat and Aqueous Polyelectrolytes under a Steady-Shear Flow. J Phys Chem B 2021; 125:6930-6944. [PMID: 34132550 DOI: 10.1021/acs.jpcb.1c02298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Materials enabling impact-energy absorption of high-velocity projectiles are of great interest for applications like aerospace. In such a frame, shear thickening fluids were found very useful. Here, we investigated nanorheological properties of neat and aqueous polyelectrolytes of low molecular weights containing poly([2-(methacryloyloxy) ethyl] trimethyl ammonium) as polycations and poly(acrylamide-co-acrylic acid) as polyanions. Results were compared with pure water. We employed nonequilibrium molecular dynamics with the SLLOD algorithm to compute the viscosity at various shear rates. Systems containing polyelectrolytes exhibit shear thickening. The analysis of molecular configurations revealed a strong disruption of the ionic structure and more clusters with smaller sizes on increasing the shear rate. Potential energies showed that shear thickening originates from an increase in intramolecular and van der Waals interactions resulting from the increasing difficultly of polyelectrolyte-based systems to relax at high shear rates. Our method and findings underscore the importance of accounting for the molecular scale in the design of materials absorbing the impact energy efficiently.
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Affiliation(s)
- Patrick A Bonnaud
- Department of Computational Science and Technology, Research Organization for Information Science and Technology, 1-18-16 Hamamatsucho, Minato, 105-0013 Tokyo, Japan
- University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-5875, Japan
| | - Hiroshi Ushiyama
- Department of Computational Science and Technology, Research Organization for Information Science and Technology, 1-18-16 Hamamatsucho, Minato, 105-0013 Tokyo, Japan
| | - Syogo Tejima
- Department of Computational Science and Technology, Research Organization for Information Science and Technology, 1-18-16 Hamamatsucho, Minato, 105-0013 Tokyo, Japan
| | - Jun-Ichi Fujita
- Institute of Applied Physics, Graduate School of Pure and Applied Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
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85
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Winkler R, Beena Unni A, Tu W, Chat K, Adrjanowicz K. On the Segmental Dynamics and the Glass Transition Behavior of Poly(2-vinylpyridine) in One- and Two-Dimensional Nanometric Confinement. J Phys Chem B 2021; 125:5991-6003. [PMID: 34048244 PMCID: PMC8279553 DOI: 10.1021/acs.jpcb.1c01245] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/13/2021] [Indexed: 11/30/2022]
Abstract
Geometric nanoconfinement, in one and two dimensions, has a fundamental influence on the segmental dynamics of polymer glass-formers and can be markedly different from that observed in the bulk state. In this work, with the use of dielectric spectroscopy, we have investigated the glass transition behavior of poly(2-vinylpyridine) (P2VP) confined within alumina nanopores and prepared as a thin film supported on a silicon substrate. P2VP is known to exhibit strong, attractive interactions with confining surfaces due to the ability to form hydrogen bonds. Obtained results show no changes in the temperature evolution of the α-relaxation time in nanopores down to 20 nm size and 24 nm thin film. There is also no evidence of an out-of-equilibrium behavior observed for other glass-forming systems confined at the nanoscale. Nevertheless, in both cases, the confinement effect is seen as a substantial broadening of the α-relaxation time distribution. We discussed the results in terms of the importance of the interfacial energy between the polymer and various substrates, the sensitivity of the glass-transition temperature to density fluctuations, and the density scaling concept.
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Affiliation(s)
- Roksana Winkler
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Aparna Beena Unni
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Wenkang Tu
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Katarzyna Chat
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Karolina Adrjanowicz
- Institute
of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research (SMCEBI), 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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86
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Zhang L, Fleck NA. Molecular dynamics simulations of ultrathin PMMA films. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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87
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Chung Y, Nam J, Son D, Lee H, Kim M, Paeng K. Direct Observations of Segmental Dynamics at the Polymer–Substrate Interface Enabled by Localizing Fluorescent Probes with Polymer Brushes. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Yura Chung
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jieun Nam
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Dongwan Son
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Hyangseok Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Myungwoong Kim
- Department of Chemistry and Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Keewook Paeng
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
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88
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Nieto Simavilla D, Abate AA, Liu J, Geerts YH, Losada-Peréz P, Napolitano S. 1D-Confinement Inhibits the Anomaly in Secondary Relaxation of a Fluorinated Polymer. ACS Macro Lett 2021; 10:649-653. [PMID: 35570757 DOI: 10.1021/acsmacrolett.1c00220] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present an experimental study of the dynamics of a well-pronounced secondary relaxation observed in bulk and ultrathin films of the fluorinated copolymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP). In proximity to the glass transition, an anomalous phenomenon is observed: the β-relaxation slows down upon heating. Measurements as a function of the film thickness show that this exceptional behavior gradually vanishes upon confinement at the nanoscale level. Regardless of sample size, the relaxation dynamics could be described in terms of the Minimal Model via an asymmetric double well potential. Supported by a structural investigation of surfaces and interfaces, our results reveal that the presence of adsorbing walls induces an increase in glass transition temperature, which counterbalances the asymmetry in the double well potential responsible for molecular motion.
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Affiliation(s)
- David Nieto Simavilla
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université libre de Bruxelles (ULB), Bruxelles 1050, Belgium
| | - Anabella A Abate
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université libre de Bruxelles (ULB), Bruxelles 1050, Belgium
| | - Jie Liu
- Laboratoire de Chimie des Polyméres, Université Libre de Bruxelles (ULB), 1050 Bruxelles, Belgium
| | - Yves H Geerts
- Laboratoire de Chimie des Polyméres, Université Libre de Bruxelles (ULB), 1050 Bruxelles, Belgium.,International Solvay Institutes of Physics and Chemistry, ULB - Campus Plaine - CP 231, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Patricia Losada-Peréz
- Experimental Soft Matter and Thermal Physics (EST), Université Libre de Bruxelles (ULB), Bruxelles 1050, Belgium
| | - Simone Napolitano
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université libre de Bruxelles (ULB), Bruxelles 1050, Belgium
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89
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Klippenstein V, Tripathy M, Jung G, Schmid F, van der Vegt NFA. Introducing Memory in Coarse-Grained Molecular Simulations. J Phys Chem B 2021; 125:4931-4954. [PMID: 33982567 PMCID: PMC8154603 DOI: 10.1021/acs.jpcb.1c01120] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Preserving the correct dynamics at the coarse-grained (CG) level is a pressing problem in the development of systematic CG models in soft matter simulation. Starting from the seminal idea of simple time-scale mapping, there have been many efforts over the years toward establishing a meticulous connection between the CG and fine-grained (FG) dynamics based on fundamental statistical mechanics approaches. One of the most successful attempts in this context has been the development of CG models based on the Mori-Zwanzig (MZ) theory, where the resulting equation of motion has the form of a generalized Langevin equation (GLE) and closely preserves the underlying FG dynamics. In this Review, we describe some of the recent studies in this regard. We focus on the construction and simulation of dynamically consistent systematic CG models based on the GLE, both in the simple Markovian limit and the non-Markovian case. Some recent studies of physical effects of memory are also discussed. The Review is aimed at summarizing recent developments in the field while highlighting the major challenges and possible future directions.
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Affiliation(s)
- Viktor Klippenstein
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Madhusmita Tripathy
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Gerhard Jung
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21 A, A-6020 Innsbruck, Austria
| | - Friederike Schmid
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 9, 55128 Mainz, Germany
| | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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90
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White RP, Lipson JEG. Dynamics across a Free Surface Reflect Interplay between Density and Cooperative Length: Application to Polystyrene. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02742] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ronald P. White
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Jane E. G. Lipson
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
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91
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Zhang B, Li J, Hu J, Liu L. Theory of polymer diffusion in polymer-nanoparticle mixtures: effect of nanoparticle concentration and polymer length. SOFT MATTER 2021; 17:4632-4642. [PMID: 33949610 DOI: 10.1039/d1sm00226k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The dynamics of polymer-nanoparticle (NP) mixtures, which involves multiple scales and system-specific variables, has posed a long-standing challenge on its theoretical description. In this paper, we construct a microscopic theory for polymer diffusion in mixtures based on a combination of the generalized Langevin equation, mode-coupling approach, and polymer physics ideas. The parameter-free theory has an explicit expression and remains tractable on a pair correlation level with system-specific equilibrium structures as input. Taking a minimal polymer-NP mixture as an example, our theory correctly captures the dependence of polymer diffusion on NP concentration and average interparticle distance. Importantly, the polymer diffusion exhibits a power law decay as the polymer length increases at dense NPs and/or a long chain, which marks the emergence of entanglement-like motion. The work provides a first-principles theoretical foundation to investigate dynamic problems in diverse polymer nanocomposites.
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Affiliation(s)
- Bokai Zhang
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China.
| | - Jian Li
- Department of Physics and Electronic Engineering, Heze University, Heze 274015, China
| | - Juanmei Hu
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China.
| | - Lei Liu
- Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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92
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White RP, Lipson JEG. A Simple New Way To Account for Free Volume in Glassy Dynamics: Model-Free Estimation of the Close-Packed Volume from PVT Data. J Phys Chem B 2021; 125:4221-4231. [PMID: 33861608 DOI: 10.1021/acs.jpcb.1c01620] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this article we focus on the important role of well-defined free volume (Vfree) in dictating the structural relaxation times, τ, of glass-forming liquids and polymer melts. Our definition of Vfree = V - Vhc, where V is the total system volume, means the use of Vfree depends on determination of Vhc, the system's volume in the limiting closely packed state. Rejecting the historically compromised use of Vfree as a dynamics-dependent fitting function, we have successfully applied a clear thermodynamics-based route to Vhc using the locally correlated lattice (LCL) model equation of state (EOS). However, in this work we go further and show that Vhc can be defined without the use of an equation of state by direct linear extrapolation of a V(T) high-pressure isobar down to zero temperature (T). The results from this route, tested on a dozen experimental systems, yield ln τ vs 1/Vfree isotherms that are linear with T-dependent slopes, consistent with the general ln τ ∼ f(T) × (1/Vfree) form of behavior we have previously described. This functional form also results by implementing a simple mechanistic explanation via the cooperative free volume (CFV) rate model, which assumes that dynamic relaxation is both thermally activated and that it requires molecular segmental cooperativity. With the degree of the latter, and thus the activation energy, being determined by the availability of free volume, the new route we demonstrate here for determination of Vfree expands the potential for understanding and predicting local dynamic relaxation in glass-forming materials.
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Affiliation(s)
- Ronald P White
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Jane E G Lipson
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
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93
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Ding Z, Liu D, Zhao K, Han Y. Optimizing Morphology to Trade Off Charge Transport and Mechanical Properties of Stretchable Conjugated Polymer Films. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00268] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Zicheng Ding
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, Shaanxi, China
| | - Dongle Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, Shaanxi, China
| | - Kui Zhao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119, Shaanxi, China
| | - Yanchun Han
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
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94
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Mears M, Zhang ZJ, Jackson RCD, Si Y, Bradford TJB, Torkelson JM, Geoghegan M. Lateral diffusion of single poly(ethylene oxide) chains on the surfaces of glassy and molten polymer films. J Chem Phys 2021; 154:164902. [PMID: 33940801 DOI: 10.1063/5.0051351] [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
Fluorescence correlation spectroscopy was used to show that the temperature-dependent diffusion coefficient of poly(ethylene oxide) (PEO) adsorbed on polystyrene and different poly(alkyl methacrylate) (PAMA) films in aqueous solution exhibited a maximum close to (but below) the surface glass transition temperature, Tgs, of the film. This elevated diffusion was observed over a small range of temperatures below Tgs for these surfaces, and at other temperatures, the diffusion was similar to that on silicon, although the diffusion coefficient for PEO on polystyrene at temperatures above Tgs did not completely decrease to that on silicon, in contrast to the PAMA surfaces. It is concluded that the enhanced surface mobility of the films near the surface glass transition temperature induces conformational changes in the adsorbed PEO. The origin of this narrow and dramatic increase in diffusion coefficient is not clear, but it is proposed that it is caused by a coupling of a dominant capillary mode in the liquid surface layer with the polymer. Friction force microscopy experiments also demonstrate an unexpected increase in friction at the same temperature as the increase in diffusion coefficient.
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Affiliation(s)
- Matthew Mears
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Zhenyu J Zhang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Ryan C D Jackson
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Yuchen Si
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Tigerlily J B Bradford
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - John M Torkelson
- Department of Chemical and Biological Engineering and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Mark Geoghegan
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
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95
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Galuska LA, Muckley ES, Cao Z, Ehlenberg DF, Qian Z, Zhang S, Rondeau-Gagné S, Phan MD, Ankner JF, Ivanov IN, Gu X. SMART transfer method to directly compare the mechanical response of water-supported and free-standing ultrathin polymeric films. Nat Commun 2021; 12:2347. [PMID: 33879775 PMCID: PMC8058343 DOI: 10.1038/s41467-021-22473-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/09/2021] [Indexed: 11/23/2022] Open
Abstract
Intrinsic mechanical properties of sub-100 nm thin films are markedly difficult to obtain, yet an ever-growing necessity for emerging fields such as soft organic electronics. To complicate matters, the interfacial contribution plays a major role in such thin films and is often unexplored despite supporting substrates being a main component in current metrologies. Here we present the shear motion assisted robust transfer technique for fabricating free-standing sub-100 nm films and measuring their inherent structural-mechanical properties. We compare these results to water-supported measurements, exploring two phenomena: 1) The influence of confinement on mechanics and 2) the role of water on the mechanical properties of hydrophobic films. Upon confinement, polystyrene films exhibit increased strain at failure, and reduced yield stress, while modulus is reduced only for the thinnest 19 nm film. Water measurements demonstrate subtle differences in mechanics which we elucidate using quartz crystal microbalance and neutron reflectometry.
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Affiliation(s)
- Luke A Galuska
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Eric S Muckley
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Zhiqiang Cao
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Dakota F Ehlenberg
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Zhiyuan Qian
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Song Zhang
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Simon Rondeau-Gagné
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada, N9B3P4
| | - Minh D Phan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - John F Ankner
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Ilia N Ivanov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Xiaodan Gu
- Center for Optoelectronic Materials and Devices, School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
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96
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Pabst F, Gabriel JP, Böhmer T, Weigl P, Helbling A, Richter T, Zourchang P, Walther T, Blochowicz T. Generic Structural Relaxation in Supercooled Liquids. J Phys Chem Lett 2021; 12:3685-3690. [PMID: 33829796 DOI: 10.1021/acs.jpclett.1c00753] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
One of the unsolved problems of dynamics in supercooled liquids are the differences in spectral shape of the structural relaxation observed among different methods and substances, and a possible generic line shape has long been debated. We show that the light scattering spectra of very different systems, e.g., hydrogen bonding, van der Waals liquids, and ionic systems, almost perfectly superimpose and show a generic line shape of the structural relaxation, following ∝ ω-1/2 at high frequencies. In dielectric spectra the generic behavior is recovered only for systems with low dipole moment, while in strongly dipolar liquids additional cross-correlation contributions mask the generic structural relaxation.
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Affiliation(s)
- Florian Pabst
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Jan Philipp Gabriel
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Till Böhmer
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Peter Weigl
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Andreas Helbling
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Timo Richter
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Parvaneh Zourchang
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Thomas Walther
- Institute of Applied Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Thomas Blochowicz
- Institute of Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
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97
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Schneider H, Roos M, Golitsyn Y, Steiner K, Saalwächter K. Dynamic Heterogeneity of Filler-Associated Interphases in Polymer Nanocomposites. Macromol Rapid Commun 2021; 42:e2100061. [PMID: 33759277 DOI: 10.1002/marc.202100061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/26/2021] [Indexed: 11/08/2022]
Abstract
Dynamically inhomogeneous polymer systems exhibit interphases with mobility gradients. These are believed to play key roles in the material's performance. A prominent example is particle-filled rubber, a special case of a crosslinked polymer nanocomposite, where favorable rubber-filler interactions may give rise to a nanoscale immobilized layer around the filler, including regions of intermediate mobility. Such intermediate domains may either form a separate shell-like layer or be a manifestation of dynamic heterogeneities, in which case the intermediately mobile material would be dispersed in the form of nanometer-sized subdomains. In this contribution, bidirectional proton NMR spin diffusion (SD) experiments applied to silica-filled acrylate rubber are combined with numerical simulations to provide microscopic insights into this question. While model calculations for different scenarios fit the given data similarly well for longer SD mixing time, the short-time data do support the presence of dynamic heterogeneities.
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Affiliation(s)
- Horst Schneider
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, Halle, 06120, Germany
| | - Matthias Roos
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, Halle, 06120, Germany
| | - Yury Golitsyn
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, Halle, 06120, Germany
| | - Kerstin Steiner
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, Halle, 06120, Germany
| | - Kay Saalwächter
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 7, Halle, 06120, Germany
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98
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Monnier X, Marina S, Lopez de Pariza X, Sardón H, Martin J, Cangialosi D. Physical Aging Behavior of a Glassy Polyether. Polymers (Basel) 2021; 13:954. [PMID: 33804594 PMCID: PMC8003685 DOI: 10.3390/polym13060954] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022] Open
Abstract
The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
| | - Sara Marina
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Xabier Lopez de Pariza
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Haritz Sardón
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Jaime Martin
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
- Centro de Investigacións Tecnolóxicas, Universidade da Coruña, Campus de Esteiro s/n, 15403 Ferrol, Spain
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 Sebastián, Spain
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99
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Rolle K, Schilling T, Westermeier F, Das S, Breu J, Fytas G. Large T g Shift in Hybrid Bragg Stacks through Interfacial Slowdown. Macromolecules 2021; 54:2551-2560. [PMID: 33814616 PMCID: PMC8016143 DOI: 10.1021/acs.macromol.0c02818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/06/2021] [Indexed: 11/29/2022]
Abstract
Studies of glass transition under confinement frequently employ supported polymer thin films, which are known to exhibit different transition temperature T g close to and far from the interface. Various techniques can selectively probe interfaces, however, often at the expense of sample designs very specific to a single experiment. Here, we show how to translate results on confined thin film T g to a "nacre-mimetic" clay/polymer Bragg stack, where periodicity allows to limit and tune the number of polymer layers to either one or two. Exceptional lattice coherence multiplies signal manifold, allowing for interface studies with both standard T g and broadband dynamic measurements. For the monolayer, we not only observe a dramatic increase in T g (∼ 100 K) but also use X-ray photon correlation spectroscopy (XPCS) to probe platelet dynamics, originating from interfacial slowdown. This is confirmed from the bilayer, which comprises both "bulk-like" and clay/polymer interface contributions, as manifested in two distinct T g processes. Because the platelet dynamics of monolayers and bilayers are similar, while the segmental dynamics of the latter are found to be much faster, we conclude that XPCS is sensitive to the clay/polymer interface. Thus, large T g shifts can be engineered and studied once lattice spacing approaches interfacial layer dimensions.
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Affiliation(s)
- Konrad Rolle
- Max-Planck-Institute
of Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Theresa Schilling
- Department
of Chemistry and Bavarian Polymer Institute, University of Bayreuth, Universitätsstr. 30, Bayreuth 95440, Germany
| | - Fabian Westermeier
- Deutsches
Elektronen Synchrotron DESY, Notkestr. 85, Hamburg D-22607, Germany
| | - Sudatta Das
- Max-Planck-Institute
of Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Josef Breu
- Department
of Chemistry and Bavarian Polymer Institute, University of Bayreuth, Universitätsstr. 30, Bayreuth 95440, Germany
| | - George Fytas
- Max-Planck-Institute
of Polymer Research, Ackermannweg 10, Mainz 55128, Germany
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100
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Ginzburg VV. Modeling the Glass Transition and Glassy Dynamics of Random Copolymers Using the TS2 Mean-Field Approach. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Valeriy V. Ginzburg
- Department of Chemical Engineering and Materials Science, Michigan State University, 428 S. Shaw Lane, Room 2100, East Lansing, Michigan 48824-1226, United States
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