Synthesis of Poly(ionic Liquid)s-block-poly(methyl Methacrylate) Copolymer-Grafted Silica Particle Brushes with Enhanced CO2 Permeability and Mechanical Performance

• Published in: Langmuir 2021-09, Vol.37 (36), p.10875-10881
• Main Authors: Wang, Zongyu, Wang, Yangyang, Chen, Jihua, Arnould, Mark, Popovs, Ilja, Mahurin, Shannon M, Chen, Hao, Wang, Tao, Dai, Sheng
• Format: Article
• Language: English
• Subjects: block copolymer; elastic modulus; gas separation; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; particle brush; silica nanoparticle
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.1c01877

Poly­(ionic liquid) (PIL)-based block copolymers are of particular interest as they combine the specific properties of PILs with the self-assembling behaviors of block copolymers, broadening the range of potential applications for PIL-based materials. In this work, three particle brushes: SiO2-g-poly­(methyl methacrylate) (PMMA), SiO2-g-PIL, and SiO2-g-PMMA-b-PIL were prepared through surface-initiated atom transfer radical polymerization. Unlike the homogeneous homopolymer particle brushes, the block copolymer particle brush SiO2-g-PMMA-b-PIL exhibited a bimodal chain architecture and unique phase-separated morphology, which were confirmed by size-exclusion chromatography and transmission electron microscopy. In addition, the influence of the introduction of the PMMA segment on the gas separation and mechanical performance of the PIL-containing block copolymer particle brushes were investigated. A significant improvement of Young’s modulus was observed in the SiO2-g-PMMA-b-PIL compared to the SiO2-g-PIL bulk films; meanwhile, their gas separation performances (CO2 permeability and CO2/N2 selectivity) were the same, which demonstrates the possibility of improving the mechanical properties of PIL-based particle brushes without compromising their gas separation performance.