Modeling of I3-Temperature dependence in polystyrene
It is known that the intensity ascribed to the ortho-positronium (I3) depends on many factors such as the experimental time and the 22Na source activity and temperature. It results that changes in I3 can not be only attributed to changes in free volume concentration. In this work we try to predict the variation of I3. Our model was based on two processes that cause inhibition and extra-formation of positronium. The former is considered to be due to free radical accumulation and the latter to the shallow trapped electron accumulation. We consider that the recombination of both species follows an Arrhenius law and their activation energies are two of the fitting parameters. This model is applied to experiments performed on polystyrene in the 20-300 K temperature range. The extracted activation energies are discussed in term of polymer relaxations.
Nicolas LAFOREST Corine BAS Charles DAUWE Jérémie De BAERDEMAEKER
LMOPS-UMR5041,Savoie Université,Campus Scientifique,73376 Le Bourget-du-lac Cedex,France NUMAT,Depar LMOPS-UMR5041,Savoie Université,Campus Scientifique,73376 Le Bourget-du-lac Cedex,France NUMAT,Department of Subatomic and Radiation Physics,Ghent University,Proefstuinstraat 86,9000 Ghent,
国际会议
第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)
武汉
英文
71
2008-05-11（万方平台首次上网日期，不代表论文的发表时间）