【摘要】 利用非平衡态Monte Carlo模拟方法,研究了剪切对ABA遥爪型三嵌段共聚物在选择性溶剂中溶胶-凝胶转变行为的影响.结果表明,一定程度的剪切流场会促使溶胶-凝胶转变浓度向低浓度方向移动.计算了剪切下体系的结构信息,包括链构型的分布、胶束的聚集数和数目、胶束簇的聚集数和数目、单链的平均尺寸和拉伸程度.结果表明,剪切使分子链沿着剪切方向被拉伸,导致分子链的尺寸变大,使体系中的分子链有更大几率可以形成桥型链,进而促进体系发生溶胶-凝胶转变.更多还原

【Abstract】 By using nonequilibrium Monte Carlo simulation approach,the shearing effects on the sol-gel transition of ABA telechelic triblock copolymers in a B block selective solvent were investigated. The simulation results show that the shear makes the sol-gel transition concentration area shifting to lower concentrations. Microscopic structure properties of the solution under shearing were simulated,such as the fractions of chains with different conformations,micelle aggregation number and micelle number,cluster aggregation number and cluster number,average size of a single chain and the stretching degree of chains. The shear makes polymer chains stretched,so telechelic chains have more opportunity to form bridge conformation,which might be the reason why a certain extent shear promotes the sol-gel transition process.更多还原