Viscosity and Surface-Promoted Slippage of Thin Polymer Films Supported by a Solid Substrate

被引：39

作者：

Chen, Fei ^{[1
]}

Peng, Dongdong ^{[1
]}

Lam, Chi-Hang ^{[3
]}

Tsui, Ophelia K. C. ^{[1
,2
]}

机构：

[1] Boston Univ, Dept Phys, Boston, MA 02215 USA

[2] Boston Univ, Div Mat Sci & Engn, Boston, MA 02215 USA

[3] Hong Kong Polytech Univ, Dept Appl Phys, Hong Kong, Hong Kong, Peoples R China

来源：

MACROMOLECULES | 2015年 / 48卷 / 14期

基金：

美国国家科学基金会;

关键词：

GLASS-TRANSITION TEMPERATURE; MOLECULAR-WEIGHT; MONODISPERSE POLYSTYRENE; DYNAMICS; MOBILITY; MOTION; CONFINEMENT; DEPENDENCE; NANOSCALE; KINETICS;

D O I：

10.1021/acs.macromol.5b01002

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Thermally activated flow dynamics of polystyrene films supported by silicon is studied for a wide range of film thickness (h(0)) and molecular weights (M-w). At low M-w, the effective viscosity of the nanometer thin gins is smaller than the bulk and decreases With decreasing h(0). This is' due to enhancement Of the total Shear flow by the augmented mobility at the free surface. As M-w increases, with h(0) becoming smaller than the polymer radius of gyration (R-g), the effective viscosity switches froth being substrate-independent to substrate-dependent. We propose that interfacial slippage then dominates and leads to plug flow. The friction coefficient is found to increase with h(0) providing h(0)/R-g < similar to 1, demonstrating a surface-promoted confinement effect.

引用

页码：5034 / 5039

页数：6

共 53 条

[1] Slip effects in polymer thin films [J].