Reduced Viscosity of the Free Surface in Entangled Polymer Melt Films

作     者：Tadanori Koga C. Li M. K. Endoh J. Koo M. Rafailovich S. Narayanan D. R. Lee L. B. Lurio S. K. Sinha 

作者机构：Chemical and Molecular Engineering Program Department of Materials Science and Engineering Stony Brook University Stony Brook New York 11794-2275 USA Department of Materials Science and Engineering Stony Brook University Stony Brook New York 11794-2275 USA Advanced Photon Source Argonne National Laboratory Argonne Illinois 60439 USA Department of Physics Northern Illinois University DeKalb Illinois 60115 USA Department of Physics University of California San Diego La Jolla California 92093 USA 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2010年第104卷第6期

页      面：066101-066101页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：NSF [CMMI-0846267] ChemMatCARS APS DOE, Office of Basic Energy Science [DE-AC02-06CH11357] Directorate For Engineering Div Of Civil, Mechanical, & Manufact Inn Funding Source: National Science Foundation 

主　　题：Thin films 

摘      要：By embedding “dilute gold nanoparticles in single polystyrene thin films as “markers, we probe the local viscosity of the free surface at temperatures far above the glass transition temperature (Tg). The technique used was x-ray photon correlation spectroscopy with resonance-enhanced x-ray scattering. The results clearly showed the surface viscosity is about 30% lower than the rest of the film. We found that this reduction is strongly associated with chain entanglements at the free surface rather than the reduction in Tg.