pH Responsive Carboxymethyl Chitosan/Poly(amidoamine) Molecular Gate Membrane for CO₂/N₂ Separation

Efficient carbon dioxide separation is an emerging field of interest in the era of energy scarcity and environmental calamity. The present study focuses on the versatile aspects of carboxymethyl chitosan and dendrimer in terms of CO2 separation. A comprehensive study has been accomplished to inspect the physicochemical properties of the prepared membrane. The mixed gas (CO2/N2) separation performances have been measured varying the temperature (60–110 °C) and sweep/feedwater flow ratio (0.33–3). The blend membrane containing 10 weight (wt.)% dendrimer presented highest CO2 permeance of ∼100 GPU and CO2/N2 selectivity ∼149 on maintenance of sweep/feedwater flow ratio 2.33 and 1.67, respectively, at an operating temperature of 90 °C. The remarkable performance displayed by the membrane has been explained with reference to the dendrimer molecular gate mechanism and the salting out effect offered by carboxymethyl chitosan matrix.