Molecular investigation of the effect of Tween surfactant on PEBA membrane in CO2 separation process

In this research, pure polyether block amide (PEBA) membrane and PEBA membrane containing tween surfactant were made using molecular simulation and analyzed from a molecular point of view. In order to investigate the structure of the membranes, their density and free fraction volume were calculated. Also, the radial distribution function was plotted in order to investigate the interaction of CO2 gas with PEBA polymer chains and tween molecules, and the permeability and solubility coefficients against CO2 and N2 gases were obtained. Moreover, the selectivity of CO2 over N2 was calculated for the membranes. The results showed an increase in the solubility and diffusion coefficients of CO2, followed by an increase in the permeability of this gas by adding tween to the polymer matrix, while the selectivity of the membrane containing tween decreased due to the increase in the diffusion coefficient of N2 in this membrane compared to the pure membrane.