FREE-VOLUME HOLE PROPERTIES NEAR-THE-SURFACE OF POLYMERS OBTAINED FROM SLOW POSITRON-ANNIHILATION SPECTROSCOPY

Authors
JEAN YC CAO H DAI GH SUZUKI R OHDAIRA T KOBAYASHI Y HIRATA K
Citation
Yc. Jean et al., FREE-VOLUME HOLE PROPERTIES NEAR-THE-SURFACE OF POLYMERS OBTAINED FROM SLOW POSITRON-ANNIHILATION SPECTROSCOPY, Applied surface science, 116, 1997, pp. 251-255
Citations number
17
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Journal title
Applied surface science → ACNP
ISSN journal
01694332
Volume
116
Year of publication
1997
Pages
251 - 255
Database
ISI
SICI code
0169-4332(1997)116:<251:FHPNOP>2.0.ZU;2-E
Abstract
We have measured the positron annihilation lifetime spectra in an epox y polymer using the electrotechnical laboratory (ETL) slow-positron fa cility 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 t he intensity decreases. The results are interpreted in terms of a Ps f ree-volume model. A larger hole size and fraction near the polymeric s urface are observed, A reduction of glass transition temperature near the surface is estimated from the WLF theory.