1
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Serna S, Wang T, Torkelson JM. Eliminating the Tg-confinement and fragility-confinement effects in poly(4-methylstyrene) films by incorporation of 3 mol % 2-ethylheyxl acrylate comonomer. J Chem Phys 2024; 160:034903. [PMID: 38235797 DOI: 10.1063/5.0189409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/22/2023] [Indexed: 01/19/2024] Open
Abstract
Nanoconfined poly(4-methylstyrene) [P(4-MS)] films exhibit reductions in glass transition temperature (Tg) relative to bulk Tg (Tg,bulk). Ellipsometry reveals that 15-nm-thick P(4-MS) films supported on silicon exhibit Tg - Tg,bulk = - 15 °C. P(4-MS) films also exhibit fragility-confinement effects; fragility decreases ∼60% in going from bulk to a 20-nm-thick film. Previous research found that incorporating 2-6 mol % 2-ethylhexyl acrylate (EHA) comonomer in styrene-based random copolymers eliminates Tg- and fragility-confinement effects in polystyrene. Here, we demonstrate that incorporating 3 mol % EHA in a 4-MS-based random copolymer, 97/3 P(4-MS/EHA), eliminates the Tg- and fragility-confinement effects. The invariance of fragility with nanoconfinement of 97/3 P(4-MS/EHA) films, hypothesized to originate from the interdigitation of ethylhexyl groups, indicates that the presence of EHA prevents the free surface from perturbing chain packing and the cooperative mobility associated with Tg. This method of eliminating confinement effects is advantageous as it relies on the simplest of polymerization methods and neat copolymer only slightly altered in composition from homopolymer. We also investigated whether we could eliminate the Tg-confinement effect with low levels of 2-ethylhexyl methacrylate (EHMA) in 4-MS-based or styrene-based copolymers. Although EHMA is structurally nearly identical to EHA, 4-MS-based and styrene-based copolymers incorporating 4 mol % EHMA exhibit Tg-confinement effects similar to P(4-MS) and polystyrene. These results support the special character of EHA in eliminating confinement effects originating at free surfaces.
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Affiliation(s)
- Sergio Serna
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
| | - Tong Wang
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
| | - John M Torkelson
- Department of Chemical and Biological Engineering, Evanston, Illinois 60208, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
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2
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Bonneau H, Arutkin M, Chen R, Forrest JA, Raphaël E, Salez T. On the bridge hypothesis in the glass transition of freestanding polymer films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:8. [PMID: 36856883 DOI: 10.1140/epje/s10189-023-00272-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Freestanding thin polymer films with high molecular weights exhibit an anomalous decrease in the glass-transition temperature with film thickness. Specifically, in such materials, the measured glass-transition temperature evolves in an affine way with the film thickness, with a slope that weakly depends on the molecular weight. De Gennes proposed a sliding mechanism as the hypothetical dominant relaxation process in these systems, where stress kinks could propagate in a reptation-like fashion through so-called bridges, i.e. from one free interface to the other along the backbones of polymer macromolecules. Here, by considering the exact statistics of finite-sized random walks within a confined box, we investigate in details the bridge hypothesis. We show that the sliding mechanism cannot reproduce the basic features appearing in the experiments, and we exhibit the fundamental reasons behind such a fact.
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Affiliation(s)
- Haggai Bonneau
- Gulliver, CNRS UMR 7083, ESPCI Paris, Univ. PSL, 75005, Paris, France
| | - Maxence Arutkin
- School of Chemistry, Center for the Physics and Chemistry of Living Systems, Ratner Institute for Single Molecule Chemistry, and the Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Rainni Chen
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - James A Forrest
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Elie Raphaël
- Gulliver, CNRS UMR 7083, ESPCI Paris, Univ. PSL, 75005, Paris, France
| | - Thomas Salez
- Univ. Bordeaux, CNRS, LOMA, UMR 5798, F-33400, Talence, France.
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3
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Wang T, Hu S, Zhang S, Peera A, Reffner J, Torkelson JM. Eliminating the Tg-Confinement Effect in Polystyrene Films: Extraordinary Impact of a 2 mol % 2-Ethylhexyl Acrylate Comonomer. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tong Wang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Sumeng Hu
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Sipei Zhang
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - Asghar Peera
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - John Reffner
- The Dow Chemical Company, 400 Arcola Road, Collegeville, Pennsylvania19426, United States
| | - John M. Torkelson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois60208, United States
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4
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Randazzo K, Bartkiewicz M, Graczykowski B, Cangialosi D, Fytas G, Zuo B, Priestley RD. Direct Visualization and Characterization of Interfacially Adsorbed Polymer atop Nanoparticles and within Nanocomposites. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Katelyn Randazzo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | | | - Bartlomiej Graczykowski
- Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, Poznan 61-614, Poland
| | - Daniele Cangialosi
- Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizábal 5, San Sebastián 20018, Spain
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal 4, 20018, San Sebastián 20018, Spain
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Biao Zuo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Rodney D. Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
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5
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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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6
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Correlation of physical aging and glass transition temperatures in ultrathin polystyrene films supported on SiO2. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Ghanekarade A, Phan AD, Schweizer KS, Simmons DS. Nature of dynamic gradients, glass formation, and collective effects in ultrathin freestanding films. Proc Natl Acad Sci U S A 2021; 118:e2104398118. [PMID: 34326262 PMCID: PMC8346796 DOI: 10.1073/pnas.2104398118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Molecular, polymeric, colloidal, and other classes of liquids can exhibit very large, spatially heterogeneous alterations of their dynamics and glass transition temperature when confined to nanoscale domains. Considerable progress has been made in understanding the related problem of near-interface relaxation and diffusion in thick films. However, the origin of "nanoconfinement effects" on the glassy dynamics of thin films, where gradients from different interfaces interact and genuine collective finite size effects may emerge, remains a longstanding open question. Here, we combine molecular dynamics simulations, probing 5 decades of relaxation, and the Elastically Cooperative Nonlinear Langevin Equation (ECNLE) theory, addressing 14 decades in timescale, to establish a microscopic and mechanistic understanding of the key features of altered dynamics in freestanding films spanning the full range from ultrathin to thick films. Simulations and theory are in qualitative and near-quantitative agreement without use of any adjustable parameters. For films of intermediate thickness, the dynamical behavior is well predicted to leading order using a simple linear superposition of thick-film exponential barrier gradients, including a remarkable suppression and flattening of various dynamical gradients in thin films. However, in sufficiently thin films the superposition approximation breaks down due to the emergence of genuine finite size confinement effects. ECNLE theory extended to treat thin films captures the phenomenology found in simulation, without invocation of any critical-like phenomena, on the basis of interface-nucleated gradients of local caging constraints, combined with interfacial and finite size-induced alterations of the collective elastic component of the structural relaxation process.
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Affiliation(s)
- Asieh Ghanekarade
- Department of Chemical, Biological and Materials Engineering, University of South Florida, Tampa, FL 33620
| | - Anh D Phan
- Faculty of Materials Science and Engineering, Phenikaa University, Hanoi 12116, Vietnam;
| | - Kenneth S Schweizer
- Department of Materials Science, University of Illinois, Urbana, IL 61801;
- Department of Chemistry, University of Illinois, Urbana, IL 61801
- Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana, IL 61801
| | - David S Simmons
- Department of Chemical, Biological and Materials Engineering, University of South Florida, Tampa, FL 33620;
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8
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Zhang S, Galuska LA, Gu X. Water‐assisted
mechanical testing of polymeric
thin‐films. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Song Zhang
- School of Polymer Science and Engineering The University of Southern Mississippi Hattiesburg Mississippi USA
| | - Luke A. Galuska
- School of Polymer Science and Engineering The University of Southern Mississippi Hattiesburg Mississippi USA
| | - Xiaodan Gu
- School of Polymer Science and Engineering The University of Southern Mississippi Hattiesburg Mississippi USA
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9
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DeFelice J, Lipson JEG. The influence of additives on polymer matrix mobility and the glass transition. SOFT MATTER 2021; 17:376-387. [PMID: 33169780 DOI: 10.1039/d0sm01634a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the region near an interface, the microscopic properties of a glass forming liquid may be perturbed from their equilibrium bulk values. In this work, we probe how the interfacial effects of additive particles dispersed in a matrix can influence the local mobility of the material and its glass transition temperature, Tg. Experimental measurements and simulation results indicate that additives, such as nanoparticles, gas molecules, and oligomers, can shift the mobility and Tg of a surrounding polymer matrix (even for relatively small concentrations of additive; e.g., 5-10% by volume) relative to the pure bulk matrix, thus leading to Tg enhancement or suppression. Additives thus provide a potential route for modifying the properties of a polymer material without significantly changing its chemical composition. Here we apply the Limited Mobility (LM) model to simulate a matrix containing additive species. We show that both additive concentration, as well as the strength of its very local influence on the surrounding matrix material, will determine whether the Tg of the system is raised or lowered, relative to the pure matrix. We demonstrate that incorporation of additives into the simple LM simulation method, which has successfully described the behavior of bulk and thin film glassy solids, leads to direct connections with available experimental and simulation results for a broad range of polymer/additive systems.
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Affiliation(s)
- Jeffrey DeFelice
- 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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10
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Han T, Wang X, Wang D, Tang BZ. Functional Polymer Systems with Aggregation-Induced Emission and Stimuli Responses. Top Curr Chem (Cham) 2021; 379:7. [PMID: 33428022 PMCID: PMC7797498 DOI: 10.1007/s41061-020-00321-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 12/18/2020] [Indexed: 01/31/2023]
Abstract
Functional polymer systems with stimuli responses have attracted great attention over the years due to their diverse range of applications. Such polymers are capable of altering their chemical and/or physical properties, such as chemical structures, chain conformation, solubility, shape, morphologies, and optical properties, in response to single or multiple stimuli. Among various stimuli-responsive polymers, those with aggregation-induced emission (AIE) properties possess the advantages of high sensitivity, fast response, large contrast, excellent photostability, and low background noise. The changes in fluorescence signal can be conveniently detected and monitored using portable instruments. The integration of AIE and stimuli responses into one polymer system provides a feasible and effective strategy for the development of smart polymers with high sensitivity to environmental variations. Here, we review the recent advances in the design, preparation, performance, and applications of functional synthetic polymer systems with AIE and stimuli responses. Various AIE-based polymer systems with responsiveness toward single physical or chemical stimuli as well as multiple stimuli are summarized with specific examples. The current challenges and perspectives on the future development of this research area will also be discussed at the end of this review.
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Affiliation(s)
- Ting Han
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Xinnan Wang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Dong Wang
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China.
| | - Ben Zhong Tang
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China.
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, and Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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11
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Ivancic RJS, Riggleman RA. Dynamic phase transitions in freestanding polymer thin films. Proc Natl Acad Sci U S A 2020; 117:25407-25413. [PMID: 33008880 PMCID: PMC7568329 DOI: 10.1073/pnas.2006703117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
After more than two decades of study, many fundamental questions remain unanswered about the dynamics of glass-forming materials confined to thin films. Experiments and simulations indicate that free interfaces enhance dynamics over length scales larger than molecular sizes, and this effect strengthens at lower temperatures. The nature of the influence of interfaces, however, remains a point of significant debate. In this work, we explore the properties of the nonequilibrium phase transition in dynamics that occurs in trajectory space between high- and low-mobility basins in a set of model polymer freestanding films. In thick films, the film-averaged mobility transition is broader than the bulk mobility transition, while in thin films it is a variant of the bulk result shifted toward a higher bias. Plotting this transition's local coexistence points against the distance from the films' surface shows thick films have surface and film-center transitions, while thin films practically have a single transition throughout the film. These observations are reminiscent of thermodynamic capillary condensation of a vapor-liquid phase between parallel plates, suggesting they constitute a demonstration of such an effect in a trajectory phase transition in the dynamics of a structural glass former. Moreover, this transition bears similarities to several experiments exhibiting anomalous behavior in the glass transition upon reducing film thickness below a material-dependent onset, including the broadening of the glass transition and the homogenization of surface and bulk glass transition temperatures.
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Affiliation(s)
- Robert J S Ivancic
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert A Riggleman
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, 19104
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12
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Wei T, Torkelson JM. Molecular Weight Dependence of the Glass Transition Temperature ( Tg)-Confinement Effect in Well-Dispersed Poly(2-vinyl pyridine)–Silica Nanocomposites: Comparison of Interfacial Layer Tg and Matrix Tg. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01577] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Tong Wei
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - John M. Torkelson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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13
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Canossa S, Filonenko GA. Color-Based Optical Detection of Glass Transitions on Microsecond Timescales Enabled by Exciplex Dynamics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1906764. [PMID: 31782848 DOI: 10.1002/adma.201906764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/14/2019] [Indexed: 05/07/2023]
Abstract
Every measurement technique operates on a given timescale and measurements using emissive small molecule sensors are no exception. A family of luminescent sensors providing first optical characterization of dynamic phenomena in polymers at a timescale of several microseconds is described. This performance originates from the dynamics manifested in the excited state of the sensor molecules where diffusioncontrolled events select the emission color while radiative phenomena define the global operation timescale. Since the mechanism responsible for signal generation is confined to the short lived excited state of emissive probe, it is possible observe an unprecedented link between the timescale of sensory action and that of photoluminescence. An application of this new methodology is demonstrated by performing general, short timescale detection of glass transitions in a temperature ranges precluding the informative range of conventional techniques by tens of degrees.
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Affiliation(s)
- Stefano Canossa
- Catalysis Engineering, Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Georgy A Filonenko
- Inorganic Systems Engineering, Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
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14
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Yang F, Presto D, Pan Y, Liu K, Zhou L, Narayanan S, Zhu Y, Peng Z, Soucek MD, Tsige M, Foster MD. Proximity to Graphene Dramatically Alters Polymer Dynamics. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
| | | | | | | | | | - Suresh Narayanan
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
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15
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Chang T, Zhang H, Shen X, Hu Z. Polymer-Polymer Interfacial Perturbation on the Glass Transition of Supported Low Molecular Weight Polystyrene Thin Films. ACS Macro Lett 2019; 8:435-441. [PMID: 35651128 DOI: 10.1021/acsmacrolett.9b00118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clarifying interfacial perturbation on polymer relaxation is important for polymer material development. Herein we investigated polymer-polymer interfacial perturbation on low molecular weight (MW) polystyrene (PS) thin film (15-180 nm) glass transition by depositing various polymers atop PS films. Overall, rubbery topcoats induced Tg depression of PS thin film (below 60 nm), while glassy topcoats induced Tg elevation of PS thin film (below 30 nm). Importantly, for the rubbery topcoat, Tg perturbation strength is largely dependent on the Tg difference between interfacial polymers and a larger Tg difference would induce stronger perturbation, while for the glassy topcoat this dependence is inconspicuous. Meanwhile, the interfacial perturbation length during PS glass transition by rubbery topcoats is estimated to be around 8 nm, while it is considered to be about 3.5 nm for glassy topcoats. The different interfacial perturbation length induced by disparate topcoats was accounted for by their different perturbation strength on adjacent PS molecules and disparate interfacial roughness. The results can promote the understanding of polymer interfacial perturbation and benefit the design and development of polymer-based materials.
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Affiliation(s)
- Tongxin Chang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Soft Condensed Matter Physics and Interdisciplinary Research Center, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Hui Zhang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Soft Condensed Matter Physics and Interdisciplinary Research Center, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Xuezhen Shen
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Soft Condensed Matter Physics and Interdisciplinary Research Center, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Zhijun Hu
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Soft Condensed Matter Physics and Interdisciplinary Research Center, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
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16
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DeFelice J, Lipson JEG. Different metrics for connecting mobility and glassiness in thin films. SOFT MATTER 2019; 15:1651-1657. [PMID: 30676595 DOI: 10.1039/c8sm02355g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Data continue to accrue indicating that experimental techniques may differ in their sensitivity to mobility and glassiness. In this work the Limited Mobility (LM) kinetic model is used to show that two metrics for tracking sample mobility yield quantitatively different results for the glass transition and mobile layer thickness in systems where free surfaces are present. Both LM metrics track the fraction of material that embodies mobile free volume; in one it is relative to that portion of the sample containing any kind (mobile and dormant) of free volume, and in the other it is relative to the overall sample. Without any kind of optimization, use of the latter metric leads to semi-quantitative agreement with experimental film results, both for the mobile layer thickness and the dependence of sample glass transition temperature on film thickness. Connecting the LM predictions with experiment also produces a semi-quantitative mapping between LM model length and temperature scales, and those of real systems.
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Affiliation(s)
- Jeffrey DeFelice
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA.
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17
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Li K, Lin Y, Lu C. Aggregation-Induced Emission for Visualization in Materials Science. Chem Asian J 2019; 14:715-729. [PMID: 30629327 DOI: 10.1002/asia.201801760] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/05/2019] [Indexed: 12/31/2022]
Abstract
Fluorescent imaging techniques have attracted much attention as a powerful tool to realize the visualization of structural and morphological evolution of various materials. However, the traditional fluorescent dyes usually suffered from aggregation-caused quenching, which severely limits the visualization results. In contrast, aggregation-induced emission (AIE) molecules with high quantum yields in the condensed state showed great opportunities for imaging techniques. In this feature article, recent progresses in visualization with AIE molecules are discussed. Assembly processes including crystallization, gelation process, and dissipative assembly have been observed. To better study information obtained regarding the processes, visualization during reactions, phase transitions, and molecular motions are successfully presented. Based on these successes, AIE molecules were further applied for phase recognition, macro-dispersion evaluation, and damage detection. Finally, we also present the outlook and perspectives, in our opinion, for the development of visualization by AIE molecules.
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Affiliation(s)
- Kaitao Li
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, P.O. Box 79, 100029, Beijing, China
| | - Yanjun Lin
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, P.O. Box 79, 100029, Beijing, China
| | - Chao Lu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, P.O. Box 79, 100029, Beijing, China
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18
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Thermoresponsive Fluorescent Semicrystalline Polymers Decorated with Aggregation Induced Emission Luminogens. CHINESE JOURNAL OF POLYMER SCIENCE 2018. [DOI: 10.1007/s10118-019-2201-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Davis MJB, Zuo B, Priestley RD. Competing polymer-substrate interactions mitigate random copolymer adsorption. SOFT MATTER 2018; 14:7204-7213. [PMID: 30131985 DOI: 10.1039/c8sm01433g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Annealing a supported polymer film in the melt state, a common practice to relieve residual stresses and erase thermal history, can result in the development of an irreversibly adsorbed nanolayer. This layer of polymer chains physically adsorbed to the substrate interface has been shown to influence thin film properties such as viscosity and glass transition temperature. Its growth is attributed to many simultaneous interactions between individual monomer units and the substrate stabilizing chains against desorption. A better understanding of how these specific polymer-substrate interactions influence the growth of the adsorbed layer is needed, particularly given how strongly the properties of geometrically-confined polymeric systems are impacted by interfaces. Here, we use homopolymers and random copolymers of styrene and methyl methacrylate to form adsorbed layers and examine the influence of chemical composition and the resulting polymer-substrate interactions on adsorbed layer growth and structure. Ellipsometric measurements reveal a non-monotonic trend between composition and thickness of the adsorbed layers that is inconsistent with the behavior normally exhibited by random copolymers, being intermediate to their respective homopolymers. We examine this trend in terms of plateau thickness and growth kinetics at two different annealing temperatures and propose a mechanism for how different polymer-substrate interactions combine to influence adsorption when copolymer films are annealed. By introducing compositional heterogeneity, this mechanism extends the study of irreversible adsorption to complex chemistries and provides for a more general understanding of how annealing should be accounted for in the proper selection and processing of polymer thin films for applications in nanotechnology.
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Affiliation(s)
- Mary J B Davis
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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20
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Zhang F, He Q, Zhou Y, Narayanan S, Wang C, Vogt BD, Foster MD. Anomalous Confinement Slows Surface Fluctuations of Star Polymer Melt Films. ACS Macro Lett 2018; 7:834-839. [PMID: 35650756 DOI: 10.1021/acsmacrolett.8b00278] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The unusually large film thickness at which confinement effects manifest themselves in surface fluctuations of unentangled four-arm star polymers has been defined using film thicknesses from 10Rg to 107Rg. For 15k four-arm star polystyrene (SPS), confinement appears at a thickness between 112 nm (40Rg) and 72 nm (26Rg), which is remarkably larger than the thicknesses at which confinement appears for unentangled 6k linear (<15 nm, <7Rg) and 6k and 14k cyclic (24 and 22 nm, respectively) polystyrenes. Data for 15k star films can be rationalized using a two-layer model with a 17 nm (6Rg) thick highly viscous layer at the substrate, which is significantly thicker than the 1Rg thick "irreversibly adsorbed" layer. For a 29 nm (10Rg) thick film, more striking confinement occurs due to the combined influence of both interfaces. These results underscore the extraordinary role long-chain branching plays in dictating surface fluctuations of thin films.
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Affiliation(s)
| | | | | | - Suresh Narayanan
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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21
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Zhang X, Zhao J, Snyder CR, Al‐Enizi A, Eltazahry A, Simmons DS, Karim A. Structure, nanomechanics, and dynamics of dispersed surfactant‐free clay nanocomposite films. POLYM ENG SCI 2018. [DOI: 10.1002/pen.24693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xiao Zhang
- Department of Polymer EngineeringUniversity of AkronAkron Ohio44325
| | - Jing Zhao
- Department of Polymer EngineeringUniversity of AkronAkron Ohio44325
- Materials Science and Engineering DivisionNational Institute of Standards and TechnologyGaithersburg Maryland20899
| | - Chad R. Snyder
- Materials Science and Engineering DivisionNational Institute of Standards and TechnologyGaithersburg Maryland20899
| | - Abdullah Al‐Enizi
- Chemistry Department, Faculty of ScienceKing Saud UniversityRiyadh11451 Saudi Arabia
| | - Ahmed Eltazahry
- Materials Science and Technology Program, College of Arts and Sciences, Qatar University, PO Box 2713, Doha, Qatar & Polymer Materials Research Department, Advanced Technology and New Materials Research InstituteCity for Scientific Research and Technology ApplicationsNew Borg El‐Arab City Alexandria Egypt
| | - David S. Simmons
- Department of Polymer EngineeringUniversity of AkronAkron Ohio44325
| | - Alamgir Karim
- Department of Polymer EngineeringUniversity of AkronAkron Ohio44325
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22
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Burroughs MJ, Christie D, Gray LAG, Chowdhury M, Priestley RD. 21st Century Advances in Fluorescence Techniques to Characterize Glass‐Forming Polymers at the Nanoscale. MACROMOL CHEM PHYS 2017. [DOI: 10.1002/macp.201700368] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Mary J. Burroughs
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Dane Christie
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Laura A. G. Gray
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Mithun Chowdhury
- Department of Chemical and Biological Engineering Princeton University Princeton NJ 08544 USA
| | - Rodney D. Priestley
- Department of Chemical and Biological Engineering Princeton Institute for the Science and Technology of Materials Princeton University Princeton NJ 08544 USA
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23
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Du X, Tang X, Fang J, Zhu DM. Quartz crystal resonator study of glass transitions in polyvinylbutyral (PVB) films. J Appl Polym Sci 2017. [DOI: 10.1002/app.45433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xianbin Du
- State Key Laboratory of Particle Detection and Electronics; University of Science and Technology of China; Hefei China
- Department of Modern Physics; University of Science and Technology of China; Hefei China
| | - Xuefeng Tang
- State Key Laboratory of Particle Detection and Electronics; University of Science and Technology of China; Hefei China
- Department of Modern Physics; University of Science and Technology of China; Hefei China
| | - Jiajie Fang
- State Key Laboratory of Particle Detection and Electronics; University of Science and Technology of China; Hefei China
- Department of Modern Physics; University of Science and Technology of China; Hefei China
| | - Da-Ming Zhu
- State Key Laboratory of Particle Detection and Electronics; University of Science and Technology of China; Hefei China
- Department of Modern Physics; University of Science and Technology of China; Hefei China
- Department of Physics and Astronomy; University of Missouri-Kansas City; Kansas City Missouri 64110
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24
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Vogt BD. Mechanical and viscoelastic properties of confined amorphous polymers. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/polb.24529] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Bryan D. Vogt
- Department of Polymer Engineering; University of Akron; Akron Ohio 44325
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25
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Molecular dynamics simulation of the glass transition temperature of fullerene filled cis-1,4-polybutadiene nanocomposites. CHINESE JOURNAL OF POLYMER SCIENCE 2017. [DOI: 10.1007/s10118-018-2015-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Qiu Z, Chu EKK, Jiang M, Gui C, Xie N, Qin W, Alam P, Kwok RTK, Lam JWY, Tang BZ. A Simple and Sensitive Method for an Important Physical Parameter: Reliable Measurement of Glass Transition Temperature by AIEgens. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01070] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zijie Qiu
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Eric K. K. Chu
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Meijuan Jiang
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Chen Gui
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ni Xie
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Wei Qin
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Parvej Alam
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ryan T. K. Kwok
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Jacky W. Y. Lam
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
| | - Ben Zhong Tang
- Guangdong
Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Hong Kong Branch of Chinese National Engineering Research
Center for Tissue Restoration and Reconstruction, Division of Life
Science, State Key Laboratory of Molecular Neuroscience, Institute
for Advanced Study, Institute of Molecular Functional Materials, Division
of Biomedical Engineering, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China
- Guangdong
Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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27
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Perez-de-Eulate NG, Di Lisio V, Cangialosi D. Glass Transition and Molecular Dynamics in Polystyrene Nanospheres by Fast Scanning Calorimetry. ACS Macro Lett 2017. [DOI: 10.1021/acsmacrolett.7b00484] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Natalia G. Perez-de-Eulate
- Centro de Física
de Materiales CFM (CSIC-UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - Valerio Di Lisio
- Department
of Chemistry, Università degli Studi di Roma “la Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Daniele Cangialosi
- Centro de Física
de Materiales CFM (CSIC-UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
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28
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Zhang M, Askar S, Torkelson JM, Brinson LC. Stiffness Gradients in Glassy Polymer Model Nanocomposites: Comparisons of Quantitative Characterization by Fluorescence Spectroscopy and Atomic Force Microscopy. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00917] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Min Zhang
- Department
of Materials Science and Engineering, ‡Department of Chemical and Biological
Engineering, and §Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Shadid Askar
- Department
of Materials Science and Engineering, ‡Department of Chemical and Biological
Engineering, and §Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - John M. Torkelson
- Department
of Materials Science and Engineering, ‡Department of Chemical and Biological
Engineering, and §Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - L. Catherine Brinson
- Department
of Materials Science and Engineering, ‡Department of Chemical and Biological
Engineering, and §Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States
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29
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Askar S, Wei T, Tan AW, Torkelson JM. Molecular weight dependence of the intrinsic size effect on T g in AAO template-supported polymer nanorods: A DSC study. J Chem Phys 2017; 146:203323. [PMID: 28571378 DOI: 10.1063/1.4978574] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Many studies have established a major effect of nanoscale confinement on the glass transition temperature (Tg) of polystyrene (PS), most commonly in thin films with one or two free surfaces. Here, we characterize smaller yet significant intrinsic size effects (in the absence of free surfaces or significant attractive polymer-substrate interactions) on the Tg and fragility of PS. Melt infiltration of various molecular weights (MWs) of PS into anodic aluminum oxide (AAO) templates is used to create nanorods supported on AAO with rod diameter (d) ranging from 24 to 210 nm. The Tg (both as Tg,onset and fictive temperature) and fragility values are characterized by differential scanning calorimetry. No intrinsic size effect is observed for 30 kg/mol PS in template-supported nanorods with d = 24 nm. However, effects on Tg are present for PS nanorods with Mn and Mw ≥ ∼175 kg/mol, with effects increasing in magnitude with increasing MW. For example, in 24-nm-diameter template-supported nanorods, Tg, rod - Tg, bulk = -2.0 to -2.5 °C for PS with Mn = 175 kg/mol and Mw = 182 kg/mol, and Tg, rod - Tg, bulk = ∼-8 °C for PS with Mn = 929 kg/mol and Mw = 1420 kg/mol. In general, reductions in Tg occur when d ≤ ∼2Rg, where Rg is the bulk polymer radius of gyration. Thus, intrinsic size effects are significant when the rod diameter is smaller than the diameter (2Rg) associated with the spherical volume pervaded by coils in bulk. We hypothesize that the Tg reduction occurs when chain segment packing frustration is sufficiently perturbed by confinement in the nanorods. This explanation is supported by observed reductions in fragility with the increasing extent of confinement. We also explain why these small intrinsic size effects do not contradict reports that the Tg-confinement effect in supported PS films with one free surface exhibits little or no MW dependence.
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Affiliation(s)
- Shadid Askar
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Tong Wei
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Anthony W Tan
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - John M Torkelson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA
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30
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Napolitano S, Glynos E, Tito NB. Glass transition of polymers in bulk, confined geometries, and near interfaces. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:036602. [PMID: 28134134 DOI: 10.1088/1361-6633/aa5284] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
When cooled or pressurized, polymer melts exhibit a tremendous reduction in molecular mobility. If the process is performed at a constant rate, the structural relaxation time of the liquid eventually exceeds the time allowed for equilibration. This brings the system out of equilibrium, and the liquid is operationally defined as a glass-a solid lacking long-range order. Despite almost 100 years of research on the (liquid/)glass transition, it is not yet clear which molecular mechanisms are responsible for the unique slow-down in molecular dynamics. In this review, we first introduce the reader to experimental methodologies, theories, and simulations of glassy polymer dynamics and vitrification. We then analyse the impact of connectivity, structure, and chain environment on molecular motion at the length scale of a few monomers, as well as how macromolecular architecture affects the glass transition of non-linear polymers. We then discuss a revised picture of nanoconfinement, going beyond a simple picture based on interfacial interactions and surface/volume ratio. Analysis of a large body of experimental evidence, results from molecular simulations, and predictions from theory supports, instead, a more complex framework where other parameters are relevant. We focus discussion specifically on local order, free volume, irreversible chain adsorption, the Debye-Waller factor of confined and confining media, chain rigidity, and the absolute value of the vitrification temperature. We end by highlighting the molecular origin of distributions in relaxation times and glass transition temperatures which exceed, by far, the size of a chain. Fast relaxation modes, almost universally present at the free surface between polymer and air, are also remarked upon. These modes relax at rates far larger than those characteristic of glassy dynamics in bulk. We speculate on how these may be a signature of unique relaxation processes occurring in confined or heterogeneous polymeric systems.
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Affiliation(s)
- Simone Napolitano
- Laboratory of Polymer and Soft Matter Dynamics, Faculté des Sciences, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium
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31
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Mathlouthi C, Hugenell F, Delpech F, Rharbi Y. Heat Capacity of Confined Polystyrene in Close-Packed Particles. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chourouk Mathlouthi
- Univ. Grenoble Alpes−LRP, F-38041 Grenoble, France
- CNRS, LRP, F-38041 Grenoble, France
| | - Frederic Hugenell
- Univ. Grenoble Alpes−LRP, F-38041 Grenoble, France
- CNRS, LRP, F-38041 Grenoble, France
| | - Françoise Delpech
- Univ. Grenoble Alpes−LRP, F-38041 Grenoble, France
- CNRS, LRP, F-38041 Grenoble, France
| | - Yahya Rharbi
- Univ. Grenoble Alpes−LRP, F-38041 Grenoble, France
- CNRS, LRP, F-38041 Grenoble, France
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32
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Kolluru PV, Chasiotis I. A master curve for the size and strain rate dependent large deformation behavior of PS nanofibers at room temperature. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.07.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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33
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Stiffness of thin, supported polystyrene films: Free-surface, substrate, and confinement effects characterized via self-referencing fluorescence. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.07.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Influence of nanoparticle inclusion on the cavity size distribution and accessible volume in polystyrene – Silica nanocomposites. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.08.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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35
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Jin K, Torkelson JM. Enhanced Tg-Confinement Effect in Cross-Linked Polystyrene Compared to Its Linear Precursor: Roles of Fragility and Chain Architecture. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01042] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Kailong Jin
- Department of Chemical and Biological
Engineering and ‡Department of Materials Science
and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - John M. Torkelson
- Department of Chemical and Biological
Engineering and ‡Department of Materials Science
and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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36
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Pfaller S, Possart G, Steinmann P, Rahimi M, Müller-Plathe F, Böhm MC. Investigation of interphase effects in silica-polystyrene nanocomposites based on a hybrid molecular-dynamics-finite-element simulation framework. Phys Rev E 2016; 93:052505. [PMID: 27300943 DOI: 10.1103/physreve.93.052505] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Indexed: 01/26/2023]
Abstract
A recently developed hybrid method is employed to study the mechanical behavior of silica-polystyrene nanocomposites (NCs) under uniaxial elongation. The hybrid method couples a particle domain to a continuum domain. The region of physical interest, i.e., the interphase around a nanoparticle (NP), is treated at molecular resolution, while the surrounding elastic continuum is handled with a finite-element approach. In the present paper we analyze the polymer behavior in the neighborhood of one or two nanoparticle(s) at molecular resolution. The coarse-grained hybrid method allows us to simulate a large polymer matrix region surrounding the nanoparticles. We consider NCs with dilute concentration of NPs embedded in an atactic polystyrene matrix formed by 300 chains with 200 monomer beads. The overall orientation of polymer segments relative to the deformation direction is determined in the neighborhood of the nanoparticle to investigate the polymer response to this perturbation. Calculations of strainlike quantities give insight into the deformation behavior of a system with two NPs and show that the applied strain and the nanoparticle distance have significant influence on the deformation behavior. Finally, we investigate to what extent a continuum-based description may account for the specific effects occurring in the interphase between the polymer matrix and the NPs.
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Affiliation(s)
- Sebastian Pfaller
- Chair of Applied Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 5, D-91058 Erlangen, Germany
| | - Gunnar Possart
- Chair of Applied Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 5, D-91058 Erlangen, Germany
| | - Paul Steinmann
- Chair of Applied Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 5, D-91058 Erlangen, Germany
| | - Mohammad Rahimi
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA
| | - Florian Müller-Plathe
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie and Centre of Smart Interfaces, Technische Universität Darmstadt, Alarich-Weiss-Straße 4, D-64287 Darmstadt, Germany
| | - Michael C Böhm
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie and Centre of Smart Interfaces, Technische Universität Darmstadt, Alarich-Weiss-Straße 4, D-64287 Darmstadt, Germany
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37
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Chen L, Torkelson JM. Tuning the Tg-confinement effect in thin polymer films via minute levels of residual surfactant which “cap” the free surface. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.02.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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DeFelice J, Milner ST, Lipson JEG. Simulating Local Tg Reporting Layers in Glassy Thin Films. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00090] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Jeffrey DeFelice
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Scott T. Milner
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jane E. G. Lipson
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
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39
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Boiko YM, Myasnikova LP. On the nature of enhanced segmental mobility at entangled amorphous polymers interfaces. Colloid Polym Sci 2016. [DOI: 10.1007/s00396-015-3806-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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40
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Han CS, Sanei SH, Alisafaei F. On the origin of indentation size effects and depth dependent mechanical properties of elastic polymers. JOURNAL OF POLYMER ENGINEERING 2016. [DOI: 10.1515/polyeng-2015-0030] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Indentation size effects have been observed in both polymers and metals but, unlike in metals, the origin of size effects in polymers is not well understood. To clarify the role of second order gradients of displacements, a model polymer is examined with spherical and Berkovich tips at probing depths between 5 and 25 μm. Applying different theories to determine the elastic modulus, it is found that with a pyramidal tip, the elastic modulus increases with decreasing indentation depth, while tests with the spherical tip yielded essentially constant values for the elastic modulus independent of indentation depth. The differences between these tips are attributed to second order displacement gradients, as they remain essentially constant with a spherical tip while they increase in magnitude with decreasing indentation depth applying a Berkovich tip.
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41
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Tan AW, Torkelson JM. Poly(methyl methacrylate) nanotubes in AAO templates: Designing nanotube thickness and characterizing the T-confinement effect by DSC. POLYMER 2016. [DOI: 10.1016/j.polymer.2015.11.054] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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42
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Zhang L, Elupula R, Grayson SM, Torkelson JM. Major Impact of Cyclic Chain Topology on the Tg-Confinement Effect of Supported Thin Films of Polystyrene. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b02474] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
| | - Ravinder Elupula
- Department
of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States
| | - Scott M. Grayson
- Department
of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States
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43
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Evans CM, Kim S, Roth CB, Priestley RD, Broadbelt LJ, Torkelson JM. Role of neighboring domains in determining the magnitude and direction of Tg-confinement effects in binary, immiscible polymer systems. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.10.059] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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44
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Tito NB, Milner ST, Lipson JEG. Enhanced diffusion and mobile fronts in a simple lattice model of glass-forming liquids. SOFT MATTER 2015; 11:7792-7801. [PMID: 26313541 DOI: 10.1039/c5sm01701g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The diffusion of mobility in bulk and thin film fluids near their glass transition is examined with a kinetic lattice model, and compared to recent experiments on bulk liquids and vapor-deposited thin film glasses. The "limited mobility" (LM) lattice model exhibits dynamic heterogeneity of mobility when the fluid is near its kinetic arrest transition; a finite-parameter second-order critical point in the LM model bearing strong resemblance to the glass transition in real fluids. The spatial heterogeneity of mobility near kinetic arrest leads to dynamics that violate the Stokes-Einstein relation. To make connections with experiment, LM model simulations of self-diffusion constants in fluids near kinetic arrest are compared to those in two organic glass-formers. In addition, simulations of mobility in films that have been temperature-jumped above kinetic arrest (starting from an arrested state) are carried out. The films develop a "front" of mobility at their free surface that progresses into the film interior at a constant rate, thereby mobilising the entire film to fluidity. The velocity of the front scales with the self-diffusion constant for analogous bulk systems-an observation consistent with experiments on vapor-deposited molecular thin films.
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Affiliation(s)
- Nicholas B Tito
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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45
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Residual stress relaxation and stiffness in spin-coated polymer films: Characterization by ellipsometry and fluorescence. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.08.036] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Lan T, Torkelson JM. Substantial spatial heterogeneity and tunability of glass transition temperature observed with dense polymer brushes prepared by ARGET ATRP. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.03.047] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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47
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Jin K, Torkelson JM. Tg and Tg breadth of poly(2,6-dimethyl-1,4-phenylene oxide)/polystyrene miscible polymer blends characterized by differential scanning calorimetry, ellipsometry, and fluorescence spectroscopy. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.04.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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48
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Zhang L, Torkelson JM. Influence of initiator fragments as chain ends on the Tg-confinement effect and dewetting of thin films of ultralow molecular weight polymer. POLYMER 2015. [DOI: 10.1016/j.polymer.2015.03.056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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49
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Xie SJ, Qian HJ, Lu ZY. The glass transition of polymers with different side-chain stiffness confined in free-standing thin films. J Chem Phys 2015; 142:074902. [DOI: 10.1063/1.4908047] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shi-Jie Xie
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Hu-Jun Qian
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Zhong-Yuan Lu
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
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50
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Ye C, Wiener CG, Tyagi M, Uhrig D, Orski SV, Soles CL, Vogt BD, Simmons DS. Understanding the Decreased Segmental Dynamics of Supported Thin Polymer Films Reported by Incoherent Neutron Scattering. Macromolecules 2015. [DOI: 10.1021/ma501780g] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Changhuai Ye
- Department
of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Clinton G. Wiener
- Department
of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Madhusudan Tyagi
- Department
of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - David Uhrig
- Center
for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | | | | | - Bryan D. Vogt
- Department
of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - David S. Simmons
- Department
of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
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