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

Abstract

This work introduces an innovative approach to enhance carbon dioxide (CO2) capture performance in mixed-matrix membranes (MMMs) by incorporating plasma-treated ceria (CeO2) nanoparticles into a polyurethane (PU)-based membrane. Functionalization of CeO2 by means of plasma aimed at improving interfacial interactions with both polymer matrix and CO2 gas molecules, with the consequent enhancement of CeO2 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 CeO2 exhibited a CO2 permeability of 51.2 barrer and a CO2/N2 ideal selectivity of approximately 76.5, demonstrating a 26.1% increase in CO2/N2 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.