Amphiphilic Graft Copolymer Nanospheres: From Colloidal Self-Assembly to CO2 Capture Membranes

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• 作者：Harim Jeon ; Dong Jun Kim ; Min Su Park ; Du Yeol Ryu ; Jong Hak Kim
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 13, 2016
• 年：2016
• 卷：8
• 期：14
• 页码：9454-9461
• 全文大小：501K
• 年卷期：0
• ISSN：1944-8252

文摘

Colloidal nanosphere self-assembly effectively generates ordered nanostructures, prompting tremendous interest in many applications such as photonic crystals and templates for inverse opal fabrication. Here we report the self-assembly of low-cost, graft copolymer nanospheres for CO₂ capture membranes. Specifically, poly(dimethylsiloxane)-graft-poly(4-vinylpyridine) (PDMS-g-P4VP) is synthesized via one-pot, free radical dispersion polymerization to give discrete monodisperse nanospheres. These nanospheres comprise a surface-anchored highly permeable PDMS layer and internal CO₂-philic P4VP spherical core. Their diameter is controllable below the submicrometer range by varying grafting ratios. The colloidal dispersion forms a long-range, close-packed hexagonal array on a substrate by inclined deposition and convective assembly. The array shows dispersion medium-dependent packing characteristics. A thermodynamic correlation is determined using different solvents to obtain stable PDMS-g-P4VP dispersions and interpreted in terms of Flory–Huggins interaction parameter. As a proof-of-concept, the implementation of these nanospheres into membranes simultaneously enhances the CO₂ permeability and CO₂/N₂ selectivity of PDMS-based transport matrixes. Upon physical aging of the solution, the CO₂/N₂ selectivity is improved up to 26, one of the highest values for highly permeable PDMS-based polymeric membranes.