Glass transitions of thin polymeric films: Speed and load dependence in lateral force microscopy

被引：49

作者：

Dinelli, F ^{[1
]}

Buenviaje, C ^{[1
]}

Overney, RM ^{[1
]}

机构：

[1] Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA

来源：

JOURNAL OF CHEMICAL PHYSICS | 2000年 / 113卷 / 05期

关键词：

Hydrostatic pressure effect - Lateral force microscopy - Polymeric film - Temperature dependence;

D O I：

10.1063/1.482012

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The glass transition of thin polymeric films can be profitably studied using lateral force microscopy (LFM) if the system is calibrated regarding operational parameters, in particular the applied load and the scanning velocity. We have established that these two parameters significantly influence the occurrence of an apparent glass transition. In particular, we have found that the local pressure, applied by the LFM tip, is insufficient to generate a hydrostatic pressure effect causing an increase in the apparent transition temperature. In fact, at a constant scan velocity and for increased load, the apparent transition temperature decreases towards the actual bulk value. Further discussions in this article are based on viscoelastic theories. Critical time scales that are characteristic for sliding are compared to polymer relaxation times, and provide an estimate of the viscosity temperature dependence. (C) 2000 American Institute of Physics. [S0021-9606(00)50428-0].

引用

页码：2043 / 2048

页数：6