How homogeneous and biphasic membranes contribute to the gas transfer: A molecular dynamics simulation study

•Separation and transfer of homogeneous and biphasic membranes were studied.•Primary and intermediate stages were chosen to reveal mechanisms.•Biphasic structure can delay the gas transmembrane time.•Selectivity can be adjusted by structural homogeneity. The behavioral processes of gas separation and transfer in homogeneous and biphasic cellulose/ionic liquid membranes have been studied using molecular dynamics simulations, with structural homogeneity being the main criterion for separation. In this work, at the primary stage, a low energy barrier at the gas-liquid interface permits continuous CO2 entry into the separation membrane and prevents interface instability. During the intermediate stage, the flow field and residence time of gas molecules are examined to demonstrate the two-sided nature of flow directionality. Additionally, the short residence time and high efficiency of CO2 release allow the biphasic membrane to perform more effectively during gas separation, through the investigation of the dissolution/separation process. In this study, it is revealed that solvent homogeneity affects gas separation at the molecular level, which may enhance the creation and design of two-dimensional materials in the future. [Display omitted]