PEBA/PSf Multilayer Composite Membranes for CO2 Separation: Influence of Dip Coating Parameters

Polyether block amide (PEBA) polymeric layers were prepared on polysulfone (PSf) supports via dip coating. The effects of the coating speed and the solution concentration on the membrane performance were studied. The membranes were characterized by scanning electron microscopy, Fourier transform infrared spectra, and gas permeation. The coating speed was adjusted in the range of 0.32–0.48 cm s−1 at a solution concentration of 3 wt % to obtain suitable membranes so that the CO2 permeance and the CO2/N2 selectivity increased by more than three and ten times, respectively, compared to other speed ranges. Statistical analysis also showed that the effect of the interaction between solution concentration and coating speed is more considerable than the separate effects of both factors. Polyether block amide/polysulfone composite membranes were prepared by the dip coating method and the effects of the coating speed and the solution concentration on the membrane performance were investigated. With increasing coating speed, the increasing withdrawal speed and the decreasing dipping time result in a thin selective layer at the appointed coating speed value.