CO₂‐Responsive Copolymers for Membrane Applications, Synthesis, and Performance Evaluation

Abstract The urgent need to mitigate climate change has spurred research into innovative carbon dioxide (CO 2 ) capture materials. In this study, the design and synthesis of CO 2 ‐responsive diblock copolymers, poly (N‐[3‐(dimethylamino)propyl]‐acrylamide)‐ b ‐poly(methyl methacrylate) (PDMAPAm‐ b ‐PMMA) are focused on via a two‐step reversible addition−fragmentation chain‐transfer (RAFT) polymerization as well as the application of the synthesized diblock copolymer as a membrane for CO 2 capture. The resulting diblock copolymer possesses distinct blocks with varying properties. The poly (N‐[3‐(dimethylamino)propyl]‐acrylamide) (PDMAPAm) block provides CO 2 ‐responsive behavior, while the poly(methyl methacrylate) (PMMA) block contributes to mechanical stability. The gas transport properties of the fabricated thin‐film composite membrane made of PDMAPAm‐ b ‐PMMA are measured. It is determined that the copolymer exhibits dual responsiveness towards CO 2 and can be tailored for use in fabrication of membranes for direct air capture (DAC).