An innovative CO₂-reactive material, namely, PDMAPAm-b-PMMA diblock copolymers, was developed by a two-step RAFT solution polymerization. The application of the synthesized diblock copolymer as a membrane for CO₂ capture was investigated. The copolymer can be customized for the fabrication of membranes and membrane adsorbers for direct air capture technologies.

Abstract

The pressing need to address climate change has driven research into novel CO₂ capture materials. Here, the synthesis of CO₂-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 CO₂ capture were investigated. The resulting diblock copolymer features distinct segments with different properties. The PDMAPAm segment offers CO₂-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 CO₂ adsorption behavior of both PDMAPAm and PDMAPAm-b-PMMA was evaluated. The copolymer exhibits responsiveness to CO₂ and can be customized for use in the fabrication of membranes and membrane adsorbers for direct air capture technologies.