Local dielectric spectroscopy of near-surface glassy polymer dynamics

被引：34

作者：

Crider, P. S. ^{[1
]}

Majewski, M. R. ^{[1
]}

Zhang, Jingyun ^{[1
]}

Oukris, H. ^{[1
]}

Israeloff, N. E. ^{[1
]}

机构：

[1] NE Univ, Dept Phys, Boston, MA 02115 USA

来源：

JOURNAL OF CHEMICAL PHYSICS | 2008年 / 128卷 / 04期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1063/1.2825301

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：

A noncontact scanning probe microscopy method was used to probe local near-surface dielectric susceptibility and dielectric relaxation in polyvinyl acetate near the glass transition. Dielectric spectra were measured from 10(-4) to 10(2) Hz as a function of temperature. The measurements probed a 20 nm thick layer below the free surface of a bulk film. A significant change in the fragility index and moderate narrowing of the distribution of relaxation times were found in the near-surface layer. In contrast to results for ultrathin films confined on or between metallic electrodes, no reduction in the dielectric strength was found, inconsistent with the immobilization of slower modes. (C) 2008 American Institute of Physics.

引用

页数：5

共 25 条

[1] Effects of confinement on material behaviour at the nanometre size scale [J].