球壳受限下非对称两嵌段共聚物自组装行为的Monte Carlo模拟研究  

Monte Carlo Study on Self-assembly Behavior of Asymmetric Diblock Copolymers under Spherical Shell Confinement

作　　者：王英英 麻家妮 崔杰[1] 韩媛媛[1] 姜伟[1] Ying-ying Wang;Jia-ni Ma;Jie Cui;Yuan-yuan Han;Wei Jiang(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院长春应用化学研究所高分子物理与化学国家重点实验室,长春130022 [2]中国科学院大学,北京100049

出　　处：《高分子学报》2018年第8期1116-1126,共11页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21474107;51433009)资助项目

摘　　要：采用Monte Carlo模拟方法研究了受限在球壳中的非对称两嵌段共聚物的自组装行为,发现球壳边界与少组分嵌段间的弱排斥作用有利于少组分嵌段形成贯通壳体的多支化柱状结构,且贯穿柱状结构的形成不依赖球壳厚度.然而当球壳厚度很薄时,无论边界对嵌段共聚物有无相互作用,少组分嵌段均可形成与壳面垂直并贯通壳体的规整柱状结构.通过对球壳中嵌段共聚物链取向的分析,给出了球壳厚度及球壳边界与少组分嵌段间排斥作用对柱状结构在球壳中取向的影响规律.Monte Carlo simulation was employed to investigate the self-assembly behaviors of asymmetric diblock copolymers under spherical shell confinements with different shell thicknesses and selectivity. The asymmetric diblock copolymer that can form hexagonally packed cylinders in bulk state was selected. The simulation results show that, when the cylinder-forming diblock copolymers are confined in spherical shells, the minority blocks can also form cylinder phases. It is found that the orientation of the cylinders highly depends on the shell thickness and selectivity. The formation of the cylinders, that are perpendicular to the shell surfaces and can penetrate the shell from inner to outer surfaces, is a prerequisite to obtain mesoporous polymer capsules. The formation conditions of such cylinders were elucidated in this study. In the neutral spherical shell, the simulation results indicate that the formation of the cylinders that penetrate the shell depends on the structural frustration parameter （i.e., the ratio of the shell thickness D to the equilibrium spacing between the cylinders in bulk, L0）. When D is incomparable to L0, the cylinders that penetrate the shell are oberved, otherwise, the cylinders that penetrate the shell disappear. It is interesting to find that the weak repulsions between the shell boundaries and the minority blocks are favorable for the minority blocks to form branched cylinders. The branched cylinders penetrate the shell from inner to outer surfaces and form multiple channels in the shell, which benefits to fabricate polymer capsules with multiple release channels. And the formation of such branched cylinders does not depend on the structural frustration parameter D/Lo. On the other hand, in the case of spherical shell with a thin thickness, the minority blocks always form well-defined cylinders that penetrate the shell, no matter whether the repulsions between the shell boundaries and the minority blocks exist. Via investigating the orientation of the polymer chains in each shell, th

关 键 词：球壳受限 嵌段共聚物 聚合物胶囊 MONTE CARLO模拟 

分 类 号：O631.1[理学—高分子化学]