Design of polymer-based CO2-membrane adsorbers for carbon capture

Abstract

This study focuses on the CO₂ capture performance of poly(N,N-dimethylaminopropyl acrylamide) (PDMAPAm) and poly(N-[3-(dimethylamino)propyl]-acrylamide)-b-poly(methyl methacrylate) (PDMAPAm-b-PMMA) diblock copolymers for fabrication of CO₂-responsive membrane adsorbers. By systematically varying the block composition of the diblock copolymer PDMAPAm-b-PMMA, optimal compositions for maximizing CO₂ adsorption capacity are identified. The adsorption mechanisms were characterized under both dry and humid conditions, revealing distinct physisorption and chemisorption pathways. The first major novelty of this work is the creation of a unified kinetic model that, for the first time, integrates polymerization kinetics with adsorption kinetics, allowing the CO₂ uptake capacity of membrane adsorbers to be directly predicted from the underlying polymer properties. A second key innovation is the use of this unified model to rationally design and fabricate a polymer membrane adsorber that achieves a CO₂ uptake capacity of 6 mmol g⁻¹, substantially exceeding the performance of commercially available polymer-based sorbents.