两嵌段共聚物反相溶剂中组装结构转变动力学的模拟研究

利用耗散粒子动力学方法,分别研究了不同结构的组装体在改变溶剂的选择性后,在溶液及界面上的结构演变动力学.模拟结果表明,在改变溶剂的选择性后,大球形胶束在溶液中转变形成反向球形胶束,而在界面上则转变形成反向环状胶束,当前模拟结果与已有的实验结果一致.此外,模拟结果还预测出,在改变溶剂的选择性后,环状胶束在溶液中转变形成反向环状胶束,而在界面处受限形成反向的支化蠕虫状胶束;蠕虫状胶束则在溶液中转变形成反向环状胶束,而在界面处受限形成多层纳米球结构;囊泡在溶液中转变形成分散的小胶束聚集体,而在界面处受限形成球形的补丁纳米粒子.

Investigation of the Transformation Dynamics of Diblock Copolymers Assemblies in Reverse Solvent via Computer Simulation

It has become a very mature and effective method to construct complex nanostructures by the selfassembly of amphiphilic block copolymer in solution or in bulk.A large number of studies have been reported that the assembly morphology of amphiphilic block copolymer can be accurately controlled by adjusting the block ratio,concentration,block compatibility and solvent conditions.Meanwhile,compared with the solution selfassembly method,the combination of substrate restriction and solvent annealing provides another way for the construction and regulation of complex nanostructures.However,due to the limitations of experimental methods,two basic problems have not been resolved.The first one is that,after the solvent selectivity was changed,the structural transformation dynamics of micelle were not clear.The second one is that,the current studies are only limited to the structural transformation process of spherical micelles in different solvents,the structural evolution kinetics of other shaped micelles or vesicles in the reverse solvent or at interface have not been reported.Thus,it is necessary to address these issues through computer simulation.In this paper,the transformation dynamics of diblock copolymers assemblies in reverse selective solvent were disclosed using dissipative particle dynamics simulation.Simulation results show that after the change of solvent selectivity,the large spherical micelles were respectively transformed into the reverse spherical micelle in solution and the ring-like micelle at the interface.The simulation results were in agreement with the available experimental result.In addition,the simulation results also predicted that after the change of solvent selectivity,the ring-like micelle,the wormlike micelle and the vesicle were transformed into the reverse ring-like micelle,the reverse ring-like micelle and multimicelle aggregate in solution,respectively,while they were transformed into the branched wormlike micelle,the multilayer nanoparticle and the patch nanoparticle at the interface,respectively.The current work provide important guidance for the design and preparation of novel nanostructures.