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Title of article :
Free-volume hole properties near the surface of polymers obtained from slow positron annihilation spectroscopy
Author/Authors :
Y.C. Jean، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1997
Pages :
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Abstract :
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 bulk 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.
Keywords :
Polymers , Epoxy , Glass transition , Slow positrons , Surfaces , Free volume
Journal title :
Applied Surface Science
Serial Year :
Link To Document :