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Xing Z, Zhu N, Yang Y, Wang X, Zuo B. Alternating chain sequence weakening of interfacial molecular interactions enhances the Tg confinement effect of polymers. Polym J 2022. [DOI: 10.1038/s41428-022-00672-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Qian C, Zhang S, Li J, Zuo B, Wang X. Segmental relaxation behavior of polystyrene chains in the cores of collapsed dry micelles tethered on the micelle film surface by a poly(acrylic acid) corona. SOFT MATTER 2014; 10:1579-1590. [PMID: 24652303 DOI: 10.1039/c3sm52761a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present an experimental investigation of the segmental relaxation behavior of polystyrene (PS) chains that are confined in a micellar core tethered by a poly(acrylic acid) (PAA) block corona on the dry film surface, along with various core density and molecular weight of PS block from below to well above the entanglement molecular weight. The results show that the onset temperature of PS chain rearrangement (T(onset)), which was much lower than the T(bulk)(g) of the corresponding PS block and higher than T(film)(g) of ultrathin PS films with corresponding thickness and molecular weights, generally increases with increasing density of the micelle core. It was found that the difference in ΔT(onset) with increasing relative density ρ/ρmin obtained from PS154-b-PAA49 and PS278-b-PAA47 micelles was large, while these from PS278-b-PAA47 and PS404-b-PAA63 was negligible, suggesting that entanglement has considerable influence on the density dependence of the T(onset) of PS chains under confinement in the micelle core on the film surface.
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Affiliation(s)
- Chao Qian
- Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China.
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Zuo B, Qian C, Yan D, Liu Y, Liu W, Fan H, Tian H, Wang X. Probing Glass Transitions in Thin and Ultrathin Polystyrene Films by Stick–Slip Behavior during Dynamic Wetting of Liquid Droplets on Their Surfaces. Macromolecules 2013. [DOI: 10.1021/ma3023734] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Biao Zuo
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Chao Qian
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Donghuan Yan
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yingjun Liu
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Wanglong Liu
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Hao Fan
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Houkuan Tian
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xinping Wang
- Department of Chemistry, Key Laboratory of Advanced Textile
Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China
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Sun Y, Henderson KJ, Jiang Z, Strzalka JW, Wang J, Shull KR. Effects of Reactive Annealing on the Structure of Poly(methacrylic acid)–Poly(methyl methacrylate) Diblock Copolymer Thin Films. Macromolecules 2011. [DOI: 10.1021/ma201000g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yan Sun
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Kevin J. Henderson
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Zhang Jiang
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Joseph W. Strzalka
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Jin Wang
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Kenneth R. Shull
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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Qi D, Ilton M, Forrest JA. Measuring surface and bulk relaxation in glassy polymers. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2011; 34:56. [PMID: 21656374 DOI: 10.1140/epje/i2011-11056-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 02/28/2011] [Accepted: 05/06/2011] [Indexed: 05/30/2023]
Abstract
We present a comprehensive study of gold nanoparticle embedding into polystyrene (PS) surfaces at temperatures ranging from T ( g ) + 8 K to T ( g ) - 83 K and times as long as 10(5) minutes. This range in times and temperatures allows the first concurrent observation of and differentiation between surface and bulk behavior in the 20 nm region nearest the free surface of the polymer film. Of particular importance is the temperature region near the bulk glass transition temperature where both surface and bulk processes can be measured. The results indicate that for the case of PS, enhanced surface mobility only exists at temperatures near or below the bulk T ( g ) value. The surface relaxation times are only weakly temperature dependent and near T ( g ), the enhanced mobility extends less than 10nm into the bulk of the film. The results suggest that both the concept of a "surface glass transition" and the use of glass transition temperatures to measure local mobility near interfaces may not universally apply to all polymers. The results can also be used to make a quantitative connection to molecular dynamics simulations of polymer films and surfaces.
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Affiliation(s)
- D Qi
- Department of Physics and Astronomy and Guelph-Waterloo Physics Institute, University of Waterloo, Ontario, Canada
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Kim S, Mundra MK, Roth CB, Torkelson JM. Suppression of the Tg-Nanoconfinement Effect in Thin Poly(vinyl acetate) Films by Sorbed Water. Macromolecules 2010. [DOI: 10.1021/ma1005606] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Soyoung Kim
- Department of Chemical and Biological Engineering
| | | | | | - John M. Torkelson
- Department of Chemical and Biological Engineering
- Department of Materials Science and Engineering
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Mok MM, Kim J, Marrou SR, Torkelson JM. Ellipsometry measurements of glass transition breadth in bulk films of random, block, and gradient copolymers. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2010; 31:239-252. [PMID: 20217174 DOI: 10.1140/epje/i2010-10569-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 11/01/2009] [Accepted: 01/20/2010] [Indexed: 05/28/2023]
Abstract
Bulk films of random, block and gradient copolymer systems were studied using ellipsometry to demonstrate the applicability of the numerical differentiation technique pioneered by Kawana and Jones for studying the glass transition temperature (T (g)) behavior and thermal expansivities of copolymers possessing different architectures and different levels of nanoheterogeneity. In a series of styrene/n -butyl methacrylate (S/nBMA) random copolymers, T (g) breadths were observed to increase from approximately 17( degrees ) C in styrene-rich cases to almost 30( degrees ) C in nBMA-rich cases, reflecting previous observations of significant nanoheterogeneity in PnBMA homopolymers. The derivative technique also revealed for the first time a substantial increase in glassy-state expansivity with increasing nBMA content in S/nBMA random copolymers, from 1.4x10(-4) K-1 in PS to 3.5x10(-4) K-1 in PnBMA. The first characterization of block copolymer T (g) 's and T (g) breadths by ellipsometry is given, examining the impact of nanophase-segregated copolymer structure on ellipsometric measurements of glass transition. The results show that, while the technique is effective in detecting the two T (g) 's expected in certain block copolymer systems, the details of the glass transition can become suppressed in ellipsometry measurements of a rubbery minor phase under conditions where the matrix is glassy; meanwhile, both transitions are easily discernible by differential scanning calorimetry. Finally, broad glass transition regions were measured in gradient copolymers, yielding in some cases extraordinary T (g) breadths of 69- 71( degrees ) C , factors of 4-5 larger than the T (g) breadths of related homopolymers and random copolymers. Surprisingly, one gradient copolymer demonstrated a slightly narrower T (g) breadth than the S/nBMA random copolymers with the highest nBMA content. This highlights the fact that nanoheterogeneity relevant to the glass transition response in selected statistical copolymers can be comparable to or exceed that observed in moderately phase-segregated gradient copolymers.
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Affiliation(s)
- M M Mok
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA
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Kim S, Hewlett SA, Roth CB, Torkelson JM. Confinement effects on glass transition temperature, transition breadth, and expansivity: comparison of ellipsometry and fluorescence measurements on polystyrene films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2009; 30:83-92. [PMID: 19784679 DOI: 10.1140/epje/i2009-10510-y] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2009] [Revised: 08/03/2009] [Accepted: 08/21/2009] [Indexed: 05/28/2023]
Abstract
Using ellipsometry, we characterized the nanoconfinement effect on the glass transition temperature (T (g)of supported polystyrene (PS) films employing two methods: the intersection of fits to the temperature (Tdependences of rubbery- and glassy-state thicknesses, and the transition mid-point between rubbery- and glassy-state expansivities. The results demonstrate a strong effect of thickness: T(g) (bulk) - T(g)(23 nm) = 10 degrees C. The T -range needed for accurate measurement increases significantly with decreasing thickness, an effect that arises from the broadening of the transition with confinement and a region below T (g) where expansivity slowly decreases with decreasing T . As determined from expansivities, the T (g) breadth triples in going from bulk films to a 21-nm-thick film; this broadening of the transition may be a more dramatic effect of confinement than the T (g) reduction itself. In contrast, there is little effect of confinement on the rubbery- and glassy-state expansivities. Compared with ellipsometry, T (g) 's from fluorescence agree well in bulk films but yield lower values in nanoconfined films: T (g)(bulk) - T (g)(23 nm) = 15( degrees ) C via fluorescence. This small difference in the T (g) confinement effect reflects differences in how fluorescence and ellipsometry report "average T (g) " with confinement. With decreasing nanoscale thickness, fluorescence may slightly overweight the contribution of the free-surface layer while ellipsometry may evenly weight or underweight its contribution.
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Affiliation(s)
- S Kim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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Zhou D, Huth H, Gao Y, Xue G, Schick C. Calorimetric Glass Transition of Poly(2,6-dimethyl-1,5-phenylene oxide) Thin Films. Macromolecules 2008. [DOI: 10.1021/ma8012543] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dongshan Zhou
- Nanjing National Laboratory of Microstructures, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and Institute of Physics, Rostock University, 18051 Rostock, Germany
| | - Heiko Huth
- Nanjing National Laboratory of Microstructures, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and Institute of Physics, Rostock University, 18051 Rostock, Germany
| | - Yun Gao
- Nanjing National Laboratory of Microstructures, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and Institute of Physics, Rostock University, 18051 Rostock, Germany
| | - Gi Xue
- Nanjing National Laboratory of Microstructures, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and Institute of Physics, Rostock University, 18051 Rostock, Germany
| | - Christoph Schick
- Nanjing National Laboratory of Microstructures, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and Institute of Physics, Rostock University, 18051 Rostock, Germany
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