两嵌段共聚物共混体系的相分离研究

用耗散粒子动力学方法（DPD）研究了由两种不同成分组成的两嵌段共聚物组成的混合体系在纳米尺度下的自组装行为．两种嵌段共聚物的聚合度相同，在稳定状态下，纯嵌段共聚物1呈层状有序结构，纯嵌段共聚物2呈无序或六角柱状结构．DPD研究表明，在两者混合体系中，随着嵌段共聚物2体积分数的增加，嵌段共聚物1只出现了层状的有序相，而嵌段共聚物2则呈现出从球状相到柱状相再到层状有序相的有趣变化，随着嵌段共聚物2对称性的增强，其形成的有序相所占的体积分数区域越小．同时，通过混合体系单体密度分布曲线和末端距分布情况，从理论上分析了混合体系的微相分离与单体分布的细节．

Microphase separation of mixtures of two diblock copolymers

The self-assembled structures of the mixtures of two different diblock copolymers were investigated by dissipative particle dynamics(DPD) simulation.Two diblock copolymers have the same degree of polymerization.In the bulk,diblock 1 forms lamella,and diblock 2 is disordered or hexagonal cylindric phase.In mixture systems,with increasing of volume fraction of diblock 2,transition from sphere to cylinder to lamella occurs in diblock 2,while only lamella occurs in diblock 1.If diblock 2 become more symmetric,the ordered phase formed by diblock 2 would take less volume fraction domain.Meanwhile,this paper utilized the monomer density distribution profiles and the end-to-end distance distribution profiles to analyze the microphase separation and the monomer distribution details in the mixture systems.