Institut Européen des Membranes, IEM, UMR 5635, ENSCM, CNRS, Universite de, Montpellier, Montpellier, 34090, France.
Macromol Rapid Commun. 2022 Jan;43(2):e2100585. doi: 10.1002/marc.202100585. Epub 2021 Nov 15.
Asymmetric and nanostructured polystyrene-block-poly(2-vinyl pyridine)-block-poly(ethylene oxide) (PS-b-P2VP-b-PEO or SVEO, S:V:EO ≈ 56:34:10, 79.5 kg mol ) thick films blended with 20 wt% of a short PS homopolymer (hPS, 10.5 kg mol ) are achieved by combining the non-solvent induced phase separation (NIPS) process with a solvent vapor annealing (SVA) treatment. Here, the NIPS step allows for the formation of a highly-permeable sponge-like substructure topped by a dense thin layer exhibiting poorly-ordered nanopores while the subsequent SVA treatment enables to reconstruct the material top surface into a porous monolayer of well-ordered hexagonal perforated lamellae (HPL). This optimized film architecture generated by NIPS-SVA shows a water permeability of 860 L h m bar , which is roughly two times higher than the flux measured through NIPS made PS-b-P2VP-b-PEO/hPS materials having poorly-ordered nanopores. The post-SVA treatment is also revealed as a powerful tool to tailor the thickness of the nanostructure formed within the blended material because monoliths entirely composed of a HPL phase are produced by increasing the time of exposure to a chloroform stream. The water flux of such PS-b-P2VP-b-PEO/hPS monoliths is found to be an order of magnitude lower than that of their asymmetric film homologues.
不对称和纳米结构的聚苯乙烯嵌段-聚（2-乙烯基吡啶）嵌段-聚（氧化乙烯）（PS-b-P2VP-b-PEO 或 SVEO，S:V:EO ≈ 56:34:10，79.5 kg mol）厚膜是通过将非溶剂致相分离（NIPS）过程与溶剂蒸气退火（SVA）处理相结合而实现的。在这里，NIPS 步骤允许形成高度可渗透的海绵状亚结构，其顶部是具有较差有序纳米孔的密集薄层，而随后的 SVA 处理能够将材料的上表面重构为具有良好有序的六边形穿孔层（HPL）的多孔单层。通过 NIPS-SVA 生成的这种优化的薄膜结构表现出 860 L h m bar 的水渗透性，这大约是通过 NIPS 制造的具有较差有序纳米孔的 PS-b-P2VP-b-PEO/hPS 材料测量的通量的两倍。后 SVA 处理也被证明是一种调整混合材料中形成的纳米结构厚度的有效工具，因为通过增加暴露于氯仿流的时间，可以生产出完全由 HPL 相组成的整体。这种 PS-b-P2VP-b-PEO/hPS 整体的水通量比其不对称薄膜同系物低一个数量级。
