CO₂‐Responsive Polymers for Membrane Applications: Synthesis and Adsorption Performance

Abstract The pressing need to address climate change has driven research into novel CO 2 capture materials. Here, the synthesis of CO 2 ‐responsive diblock copolymers, i.e., poly( N ‐[3‐(dimethylamino)propyl]‐acrylamide)‐ b ‐poly(methyl methacrylate) (PDMAPAm‐ b ‐PMMA) through a two‐step RAFT polymerization process, as well as the use of the synthesized diblock copolymer as a membrane for CO 2 capture were investigated. The resulting diblock copolymer features distinct segments with different properties. The PDMAPAm segment offers CO 2 ‐responsive characteristics, while the PMMA segment provides mechanical stability. The gas transport properties of the fabricated thin‐film composite membrane composed of PDMAPAm‐ b ‐PMMA or PDMAPAm and polydimethylsiloxane with a gutter layer were measured and the CO 2 adsorption behavior of both PDMAPAm and PDMAPAm‐ b ‐PMMA was evaluated. The copolymer exhibits responsiveness to CO 2 and can be customized for use in the fabrication of membranes and membrane adsorbers for direct air capture technologies.