Li Yayuan, Xu Yawei, Cao Shubo, Zhao Yongbin, Qu Ting, Iyoda Tomokazu, Chen Aihua
School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
Shandong Oubo New Material Co Ltd, Dongying Part Economic Development Zone, Shangdong, 257088, P. R. China.
Macromol Rapid Commun. 2017 Mar;38(5). doi: 10.1002/marc.201600662. Epub 2017 Jan 24.
Nanoporous thin films with pore size of sub-10 nm are fabricated using an acid-cleavable block copolymer (BCP), a benzoic imine junction between poly(ethylene oxide) (PEO) and poly(methacrylate) (PMAAz) bearing an azobenzene side chain (denoted as PEO-bei-PMAAz) as the precursor. After a thermal annealing, the block copolymers are self-assembled to form highly ordered PEO cylinders within a PMAAz matrix normal to the film, even in the case of low BCP molecular weight due to the existing of the liquid crystalline (LC) azobenzene rigid segment. Thus, PMAAz thin films with pore size of ≈7 nm and density of ≈10 cm are obtained after removal of the PEO minor phase by breaking the benzoic imine junction under mild acidic conditions. This work enriches the nanoporous polymer films from BCP precursors and introduces the LC property as a functionality which can further enhance the mechanical properties of the films and broaden their applications.
使用一种可酸解的嵌段共聚物（BCP）制备孔径小于10纳米的纳米多孔薄膜，该BCP是聚环氧乙烷（PEO）与带有偶氮苯侧链的聚甲基丙烯酸酯（PMAAz）之间的苯甲酸亚胺连接体（记为PEO-bei-PMAAz）作为前体。经过热退火后，即使在低BCP分子量的情况下，由于液晶（LC）偶氮苯刚性链段的存在，嵌段共聚物也会自组装形成垂直于薄膜的PMAAz基质内高度有序的PEO圆柱体。因此，在温和酸性条件下通过破坏苯甲酸亚胺连接体去除PEO次要相后，可获得孔径约为7纳米、密度约为10厘米的PMAAz薄膜。这项工作丰富了基于BCP前体的纳米多孔聚合物薄膜，并引入了液晶特性作为一种功能，可进一步增强薄膜的机械性能并拓宽其应用范围。
