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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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Abstract
Reflectometry experiments probe the scattering length density along the normal of interfaces by analysing the specularly scattered intensity. Lateral fluctuations result in intensity scattered away from the specular condition. In this paper the principles and peculiarities of grazing incidence scattering experiments are explained. One specific example, the self assembly of polymer micelles close to interfaces, is taken as a show case in order to introduce the scattering geometry and accessible length scales. The basic idea of the distorted wave Born approximation is lined out and some scientific examples are summarized.
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Xia T, Qin Y, Huang Y, Huang T, Xu J, Li Y. Sequence control of phase separation and dewetting in PS/PVME blend thin films by changing molecular weight of PS. J Chem Phys 2016; 145:204903. [PMID: 27908140 DOI: 10.1063/1.4968556] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The morphology evolution mechanism of polystyrene (PS)/poly (vinyl methyl ether) (PVME) blend thin films with different PS molecular weights (Mw) was studied. It was found that the morphology evolution was closely related to the molecular weight asymmetry between PS and PVME. In the film where Mw(PS) ≈ Mw(PVME), dewetting happened at the interface between the bottom layer and substrate after SD phase separation. While in the film where Mw(PS) >> Mw(PVME), dewetting happened at the interface between the middle PS/PVME blend layer and bottom PVME layer near the substrate prior to phase separation. The different sequences of phase separation and dewetting and different interface for dewetting occurrence were studied by regarding the competitive effects of viscoelasticity contrast between polymer components and preferential wetting between PVME and the substrate. The viscoelastic nature of the PS component played a crucial role in the sequence of phase separation and dewetting.
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Affiliation(s)
- Tian Xia
- College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400050, China
| | - Yaping Qin
- College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400050, China
| | - Yajiang Huang
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Ting Huang
- College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400050, China
| | - Jianhui Xu
- College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China
| | - Youbing Li
- College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400050, China
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Zhu Y, Yang Q, You J, Li Y. Composition fluctuation intensity effect on the stability of polymer films. RSC Adv 2016. [DOI: 10.1039/c6ra12723a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The composition fluctuation intensity dependence of the stability of a polymer film with a tiny amount of miscible component.
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Affiliation(s)
- Yu Zhu
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Qiucheng Yang
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Jichun You
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Yongjin Li
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
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Xia T, Ogawa H, Inoue R, Nishida K, Yamada NL, Li G, Kanaya T. Dewetting Process of Deuterated Polystyrene and Poly(vinyl methyl ether) Blend Thin Films via Phase Separation. Macromolecules 2013. [DOI: 10.1021/ma400506f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Tian Xia
- College of Polymer Science and
Engineering, Sichuan University, Chengdu
610065, China
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
| | - Hiroki Ogawa
- Japan Synchrotron Radiation Research Institute, Sayo-gun, Hyogo-ken 679-5198,
Japan
| | - Rintaro Inoue
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
| | - Koji Nishida
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
| | - Norifumi L. Yamada
- High Energy Accelerator Research Organization, Tokai, Ibaraki-ken 319-1106,
Japan
| | - Guangxian Li
- College of Polymer Science and
Engineering, Sichuan University, Chengdu
610065, China
| | - Toshiji Kanaya
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
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Mitamura K, Yamada NL, Sagehashi H, Torikai N, Arita H, Terada M, Kobayashi M, Sato S, Seto H, Goko S, Furusaka M, Oda T, Hino M, Jinnai H, Takahara A. Novel neutron reflectometer SOFIA at J-PARC/MLF for in-situ soft-interface characterization. Polym J 2012. [DOI: 10.1038/pj.2012.156] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Xu L, Sharma A, Joo SW. Dewetting of Stable Thin Polymer Films Induced by a Poor Solvent: Role of Polar Interactions. Macromolecules 2012. [DOI: 10.1021/ma301227m] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lin Xu
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
| | - Ashutosh Sharma
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
- Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sang Woo Joo
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
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Ma M, Chen F, Wang K, Zhang Q, Deng H, Li Z, Fu Q. Anisotropic Dewetting Holes with Instability Fronts in Ultrathin Films of Polystyrene/Poly(ε-caprolactone) Blend. Macromolecules 2012. [DOI: 10.1021/ma3000779] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Meng Ma
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Feng Chen
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Ke Wang
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Qin Zhang
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Hua Deng
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhongming Li
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Qiang Fu
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
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Ma M, He Z, Yang J, Chen F, Wang K, Zhang Q, Deng H, Fu Q. Effect of film thickness on morphological evolution in dewetting and crystallization of polystyrene/poly(ε-caprolactone) blend films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:13072-81. [PMID: 21936570 DOI: 10.1021/la2036289] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In this Article, the morphological evolution in the blend thin film of polystyrene (PS)/poly(ε-caprolactone) (PCL) was investigated via mainly AFM. It was found that an enriched two-layer structure with PS at the upper layer and PCL at the bottom layer was formed during spinning coating. By changing the solution concentration, different kinds of crystal morphologies, such as finger-like, dendritic, and spherulitic-like, could be obtained at the bottom PCL layer. These different initial states led to the morphological evolution processes to be quite different from each other, so the phase separation, dewetting, and crystalline morphology of PS/PCL blend films as a function of time were studied. It was interesting to find that the morphological evolution of PS at the upper layer was largely dependent on the film thickness. For the ultrathin (15 nm) blend film, a liquid-solid/liquid-liquid dewetting-wetting process was observed, forming ribbons that rupture into discrete circular PS islands on voronoi finger-like PCL crystal. For the thick (30 nm) blend film, the liquid-liquid dewetting of the upper PS layer from the underlying adsorbed PCL layer was found, forming interconnected rim structures that rupture into discrete circular PS islands embedded in the single lamellar PCL dendritic crystal due to Rayleigh instability. For the thicker (60 nm) blend film, a two-step liquid-liquid dewetting process with regular holes decorated with dendritic PCL crystal at early annealing stage and small holes decorated with spherulite-like PCL crystal among the early dewetting holes at later annealing stage was observed. The mechanism of this unusual morphological evolution process was discussed on the basis of the entropy effect and annealing-induced phase separation.
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Affiliation(s)
- Meng Ma
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
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