Effect of surface engineering of nanofillers using plasma-treated water for carbon dioxide capture in mixed matrix membranes: Experimental and molecular dynamics

This work introduces an innovative approach to enhance carbon dioxide ( CO 2 ) capture performance in mixedmatrix membranes (MMMs) by incorporating plasma-treated ceria (CeO 2 ) nanoparticles into a polyurethane (PU)-based membrane. Functionalization of CeO 2 by means of plasma aimed at improving interfacial interactions with both polymer matrix and CO 2 gas molecules, with the consequent enhancement of CeO 2 nanoparticles dispersion within the matrix and improvement of gas separation performance. Based on the results of the gas separation tests, the PU membrane containing 5 wt% plasma-treated CeO 2 exhibited a CO 2 permeability of 51.2 barrer and a CO 2 / N 2 ideal selectivity of approximately 76.5, demonstrating a 26.1% increase in CO 2 / N 2 ideal selectivity compared to the pristine PU membrane. However, a further increase in filler content to 10 wt% led to nanoparticle agglomeration, resulting in a decrease in selectivity due to the formation of non-selective pathways through the membrane. Molecular dynamics (MD) simulations corroborated these experimental findings, providing additional insights into the interaction mechanisms between the polymer matrix and the functionalized nanoparticles.