多分散性对两亲性两嵌段共聚物在选择性溶剂中自组装行为影响的Monte Carlo模拟  

EFFECT OF POLYDISPERSITY ON THE SELF-ASSEMBLY OF AMPHIPHILIC DIBLOCK COPOLYMER IN A SELECTIVE SOLVENT:A MONTE CARLO STUDY

作　　者：崔杰[1,2] 张晓旭[3] 韩媛媛[1] 姜伟[1] 

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]中国科学院研究生院,北京100039 [3]东北师范大学物理学院,长春130024

出　　处：《高分子学报》2011年第4期421-426,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20874099;50930001);国家创新研究群体科学基金(基金号50921062);国家杰出青年科学基金(基金号50725312);国家重点基础研究项目(项目号2007CB808000)资助

摘　　要：采用Monte Carlo模拟方法研究了多分散性AB两亲性两嵌段共聚物在选择性溶剂中的自组装行为.模拟结果表明,嵌段共聚物的多分散性对体系在选择性溶剂中自组装所形成的胶束形貌结构有很大影响.当AB两嵌段共聚物的多分散系数由1.0增加至1.4时,体系中自组装所形成的胶束将会发生由囊泡到片层直至球状的一系列形态转变.通过统计分析体系中未形成胶束的单链数目和其在体系中所占的百分含量随多分散系数的变化以及对体系自组装动力学过程的研究发现,这一系列形态转变是由于多分散体系中链长较短的高分子链数目的增加而导致.The effect of polydispersity on the self-assembly of amphiphilic diblock copolymer in a selective solvent was studied by means of Monte Carlo simulation.The polydisperse diblock copolymer system was constructed via the mixing of three amphiphilic diblock copolymer chains different in lengthi,.e.,A2B2,A2B6 and A2B10.The simulation results show that the micelle morphologies formed by AB diblock copolymers in a selective solvent changed from vesicle to lamellae,then to spheres with an increase in polydispersity index（PDI） from 1.0 to 1.4.Through the analysis of the variations of the number and fractions of free single chains with the increase of PDI in each system,it is found that the number of short chains（i.e.A2B2） which aggregate into micelles increased with an increasing PDI.Meanwhilet,he self-assembly processes of diblock copolymers with different PDI in a selective solvent reveal that the increasing number of short chains can increase the surface area of the micellesl,eading to a disadvantage for the fusion between small micelles during the self-assembly.The increase of the surface area of micelles is the main reason of the morphological transition from large-sized vesicles to small-sized spheres when the PDI is increased.These simulation results indicate that the micelle morphologies and their mutual transitions in a selective solvent can be tuned by the control of the polydispersity of AB diblock copolymers.

关 键 词：多分散性 两亲性两嵌段共聚物 自组装 MONTE CARLO模拟 

分 类 号：O631.5[理学—高分子化学]