Free-volume hole properties near the surface of polymers obtained from slow positron annihilation spectroscopy

被引：30

作者：

Jean, YC

Cao, H

Dai, GH

Suzuki, R

Ohdaira, T

Kobayashi, Y

Hirata, K

机构：

[1] ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN

[2] NATL INST MAT & CHEM RES,TSUKUBA,IBARAKI 305,JAPAN

来源：

APPLIED SURFACE SCIENCE | 1997年 / 116卷

基金：

美国国家科学基金会; 日本科学技术振兴机构;

关键词：

free volume; glass transition; polymers; epoxy; surfaces; slow positrons;

D O I：

10.1016/S0169-4332(96)01064-1

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：

We have measured the positron annihilation lifetime spectra in an epoxy polymer using the electrotechnical laboratory (ETL) slow-positron facility as a function of positron energy from 0.2 to 3.0 keV. The ortho-positronium lifetime from the hulk increases near the surface while the intensity decreases. The results are interpreted in terms of a Ps free-volume model. A larger hole size and fraction near the polymeric surface are observed, A reduction of glass transition temperature near the surface is estimated from the WLF theory.

引用

页码：251 / 255

页数：5

共 17 条

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