嵌段共聚物溶液胶束温度行为的正电子湮没研究  

Study of Temperature Effect of Micellar Solutions of PSDMS Block Copolymer in n-Heptane by Positron Annihilation

作　　者：熊兴民 杨巨华[1] 叶美玲[2] 张迎玖 施良和[2] 

机构地区：[1]中国科学院高能物理研究所,北京100080 [2]中国科学院化学研究所,北京100080

出　　处：《物理化学学报》1995年第6期541-546,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金;中科院核分析技术开放实验室支持项目

摘　　要：用正电子寿命技术研究了聚苯乙烯—二甲基硅氧烷／正庚烷二嵌段共聚物溶液胶束的温度行为．结果表明正电子湮没参数对溶液中出现的结构和微观环境的变化十分灵敏．在一定的温度范围o-Ps寿命和强度的陡然变化反映了溶液中共聚物分子聚集态随温度经历不同阶段的变化，超过临界胶束温度o-Ps寿命随温度增高而迅速地增大，这一行为反映了分子聚集体解离成自由共聚物分子的过程．The positron lifetime technique has been used to study the temperature behavior of micelle in solution of polystyrene-polydimethylsiloxane diblock copolymer in n-heptane. The results indicate that positron annihilation parameters are found to be sensitive to structural and microphase changes taking place in the micellar solutions. The abrupt changes in the o-Ps lifetime and intensity observed at certain temperature appear to be associated with variations in the aggregation state of the copolymer molecules in solutions. Above the critical micelle temperature the o-Ps lifetime increases sharply with increasing temperature. This behavior indicates the process of disintegration of molecular aggregtes to free copolymer molecules.

关 键 词：正电子湮没 嵌段共聚物 胶束 温度效应 

分 类 号：O631.4[理学—高分子化学]