Insights into ordered microstructures and ordering mechanisms of ABC star terpolymers by integrating dynamic self-consistent field theory and variable cell shape methods.
Insights into ordered microstructures and ordering mechanisms of ABC star terpolymers by integrating dynamic self-consistent field theory and variable cell shape methods.
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DOI：
10.1039/c4sm00658e
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发表时间：
2014-07
期刊：
影响因子：
3.4
通讯作者：
Xuguang Cao;Liangshun Zhang;Liquan Wang;Jiaping Lin
中科院分区：
文献类型：
--
作者：
Xuguang Cao;Liangshun Zhang;Liquan Wang;Jiaping Lin
将非均相聚合物流体的动态自洽场(SCF)理论与自动调节晶胞形状和大小的可变晶胞形状(VCS)方法相结合，研究嵌段共聚熔体的有序微结构和有序化机理。利用这种模拟方法，我们首先重新考察了最简单的AB两嵌段共聚物的微相分离，并与动态超临界流体理论的结果进行了比较，验证了新方法的有效性和有效性。选择合适的驰豫参数，可以有效地加速体系向稳定的形态转变，而不会产生扭曲或缺陷。然后用动态SCF/VCS方法鉴定了ABC星型三元共聚物的丰度形态，并探讨了星型三元共聚物熔体从均相态急冷的有序化机理。预测了一系列不同的有序微结构，包括二维平铺图案、分层结构和普通微结构。在ABC星形聚合物的无序-有序转变过程中，发现了三种有序化机制，即一步有序化、快慢有序化和逐步有序化。ABC星型三元共聚物熔体的微相分离过程受星型三元共聚物的组成和相互作用参数的影响很大。
A theoretical approach coupling dynamic self-consistent field (SCF) theory for inhomogeneous polymeric fluids and variable cell shape (VCS) method for automatically adjusting cell shape and size is developed to investigate ordered microstructures and the ordering mechanisms of block copolymer melts. Using this simulation method, we first re-examined the microphase separation of the simplest AB diblock copolymers, and tested the validity and efficiency of the novel method by comparing the results with those obtained from the dynamic SCF theory. An appropriate relaxation parameter of the VCS method effectively accelerates the system towards a stable morphology without distortions or defects. The dynamic SCF/VCS method is then applied to identify the richness morphologies of ABC star terpolymers and explore the ordering mechanisms of star terpolymer melts quenched from homogenous states. A diverse range of ordered microstructures, including two-dimensional tiling patterns, hierarchical structures and ordinary microstructures, are predicted. Three types of ordering mechanisms, namely, one-step, quick-slow and step-wise procedures, are discovered in the disorder-to-order transition of ABC star terpolymers. The procedures of microphase separation in the ABC star terpolymer melts are remarkably affected by the composition of star terpolymers and the strength of interaction parameters.