界面极化和自由体积尺寸对正电子素形成的影响  

Influence of interfacial polarization and size of free volume hole on positronium formation

作　　者：夏亚一[1] 齐陈泽[2] 王宝义[3] 孙旭东[2] 胡幼华[2] 王天民[4] 

机构地区：[1]兰州大学材料科学系,兰州730000 [2]绍兴文理学院应用化学研究所,绍兴312000 [3]中国科学院高能物理研究所,北京100049 [4]北京航空航天大学理学院,北京100083

出　　处：《核技术》2005年第6期419-423,共5页Nuclear Techniques

基　　金：浙江省自然科学基金(RC01050;501066)项目

摘　　要：测量了高冲聚苯乙烯、高密度聚乙烯、低密度聚乙烯、聚丙烯和高冲聚苯乙烯分别与其它3种材料的共混物随时间测量的正电子湮没寿命谱。结果显示,所有测量样品的长寿命组分τ3值不随时间变化,而且大部分样品相应的长寿命强度I3也保持不变,仅有几种聚合物随时间呈现减小。I3的减小被认为是在测量过程中聚合物表面电场形成的结果,I3保持不变则与聚合物体内的自由体积尺寸和在测量过程中形成的界面极化密切相关。The measurements of positron annihilation lifetime spectra (PALS) have been performed on high impact polystyrene (HIPS), polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE) and a number of HIPS-PP, HIPS-HDPE and HIPS-LDPE blends. The results show that the longest lifetime component τ3 remains constant during extending PALS measurement for all measured polymers, and corresponding intensity I3 with time decreases only for several polymers. The decrease of I3 is interpreted as a result of electric field build up during prolonged PALS measurement. The constant I3 with time has been found to correlate with interfacial polarization during measurement and larger size of free volume holes in the polymers.

关 键 词：高冲聚苯乙烯 高密度聚乙烯 低密度聚乙烯 聚丙烯 共混物 正电子湮没 

分 类 号：O631.11[理学—高分子化学]