A Computational Study of Water Sorption and Its Effect on CO2 Separation Performance in Graphene-Oxide Based Membranes

Membrane technologies have been actively studied as a potentially viable energy-saving alternative for CO₂ capture in comparison to conventional absorption-based amine scrubbing. Recently, graphene oxide (GO) has gained much attention as an advanced material for gas-separation membranes by virtue of its ultra-thin laminate structure suitable for use as a separation membrane. Moreover, water vapor can be absorbed into the hydrophilic GO membrane in humid conditions. Because of the solubility difference between CO₂ and other nonpolar gases in water, the intercalated water can increase the selectivity of CO₂ over nonpolar gases such as N₂. Hence, a detailed understanding of the water sorption behavior of GO-based membranes is important in order to better evaluate and also find an effective way to improve their CO₂ separation performance.

This poster will present some results of our recent computational studies of water sorption and its effect on CO₂ separation performance in GO-based membranes, especially the influences of relative humidity, OH group content and distribution, and GO geometry. This presentation will specially touch on changes in the amount and dynamics of intercalated water under varying conditions of humidity, temperature, and GO structure, along with the effects of intercalated water on the separation of CO₂ from a mixture of gases. The improved understanding helps to better understand the properties and performance of GO-based membranes for CO₂ separation, and will also contribute to the optimal design and development of more efficient GO-based membrane systems.