title: Nanoporous Films with Sub-10 nm in Pore Size from Acid-Cleavable Block Copolymers.
abstract: 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 ≈1012cm-2are 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.
authors.affiliation: School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
authors.forename: Yayuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
authors.forename: Shubo
authors.initials: S
authors.lastname: Cao
authors.affiliation: Shandong Oubo New Material Co Ltd, Dongying Part Economic Development Zone, Shangdong, 257088, P. R. China.
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Qu
authors.affiliation: Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midoriku, Yokohama, Kanagawa, 226-8503, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Iyoda
authors.affiliation: School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Haidian District, Beijing, 100191, P. R. China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Chen
mesh_terms: D000143:Acids / Q000737:chemistry*; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
chemical_list: D000143:Acids; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D011092:Polyethylene Glycols
keywords: block copolymer; nanoporous film; self-assembly; sub-10 nm