PEG-b-PDMS-b-PEG微相分离结构的耗散粒子动力学模拟

为了探讨PEG-b-PDMS-b-PEG三嵌段共聚物中链段含量对其微相分离结构的影响规律,采用耗散粒子动力学模拟方法,建立了不同PEG链段含量的共聚物介观结构模型.通过介观相分离过程及形态的模拟,分析了相形貌与侧链接枝密度的依赖关系.模拟结果表明,随着嵌段共聚物体系中侧链密度的增加,微相分离结构呈现规律性变化,出现了粒状、岛状及双连续相等不同形态的介观结构.同时,对PEG含量为28％的PEG-b-PDMS-b-PEG三嵌段梳型共聚物的原子力形貌观察结果表明,其具有一定的相分离结构.

Dissipative particle dynamics simulation of the microphase separation of PEG-b-PDMS-b-PEG

In order to discuss the effect of chain segment contents on the microphase separation structure of triblock comb copolymer PEG-b-PDMS-b-PEG,mesoscopic structure models of copolymers with varying PEG segment contents were built using the dissipative particle dynamics(DPD) method.Through simulation of the meso-phase separation process and morphology,the relationship between the morphology of the meso-phase and graft density was analyzed.It was indicated that regular changes appear in microphase structures with the increase of graft density in copolymers;furthermore,granular,island,and bicontinuous phase structures emerge in the structures.At the same time,the atomic force microscope image result of the triblock comb copolymer PEG-b-PDMS-b-PEG with 28% PEG molar content shows that the copolymer has certain microphase separation structures.