Modeling Microstructure Formation in Block Copolymer Membranes Using Dynamical Self-Consistent Field Theory
Modeling Microstructure Formation in Block Copolymer Membranes Using Dynamical Self-Consistent Field Theory
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DOI：
10.1021/acsmacrolett.2c00611
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发表时间：
2022-12-15
影响因子：
7.015
通讯作者：
Fredrickson, Glenn H.
中科院分区：
文献类型：
--
作者：
Grzetic, Douglas J.;Cooper, Anthony J.;Fredrickson, Glenn H.
嵌段共聚物由于能够通过自组装和非溶剂诱导相分离(SNIPS)相结合的方法形成等孔整不对称膜而成为超滤膜的候选材料，近年来引起了人们的兴趣。然而，表面层和亚结构形态对与SNIP相关的加工变量的依赖性还没有被很好地理解，也不清楚在经历这种凝聚的嵌段共聚物中微相和大相分离之间的相互作用。在这里，我们用动态自洽场理论模拟了嵌段共聚物薄膜在剪切过程中的微结构演变，发现只有当溶剂和非溶剂具有相反的嵌段选择性时，这种薄膜才能形成所需的海绵状非对称多孔亚结构，否则形成致密的非多孔微相分离薄膜。我们的结果对嵌段共聚物膜加工过程中溶剂和非溶剂的选择具有重要的指导意义。
Block copolymers have attracted recent interest as candidate materials for ultrafiltration membranes, due to their ability to form isoporous integral-asymmetric membranes by the combined processes of self-assembly and nonsolvent-induced phase separation (SNIPS). However, the dependence of surface layer and substructure morphologies on the processing variables associated with SNIPS is not well understood nor is the interplay between microphase and macrophase separation in block copolymers undergoing such coagulation. Here, we use dynamical self-consistent field theory to simulate the microstructure evolution of block copolymer films during SNIPS and find that such films form the desired sponge-like asymmetric porous substructure only if the solvent and nonsolvent have opposite block selectivities and that otherwise they form a dense nonporous microphase-separated film. Our results could have important implications for the choices of solvent and nonsolvent in the processing of block copolymer membranes.