Investigating gas permeation behavior and morphology of PC membranes

The gas separation properties of polycarbonate membranes were investigated in this study. PC membranes were prepared via dry phase inversion technique. The effects of membrane preparation conditions, including solvent type, non-solvent type, non-solvent/solvent (vol/vol %), polymer weight fraction, and drying temperature on the gas separation properties of PC membranes were investigated using Taguchi experimental design. The permeation of pure O2, N2, and CO2 gases were examined. The results indicated that the CO2 permeability was evidently higher than those of the other gases. To get the maximum selectivity and optimum condition for selectivity and permeability, Taguchi analysis was used. Polymer weight fraction showed the most important effect on the separation characteristics of the prepared PC membranes. Membranes prepared with n-propanol as non-solvent indicated improved gas separation behavior. To get the highest permselectivities of CO2/N2 or O2/N2, the amount of added n-propanol to the casting solution should be zero. While, optimum point for high selectivity and permeability of CO2/N2 or O2/N2 separation can be reached with 5% of n-propanol as non-solvent. Trade-off evaluation also showed that certain types of the prepared PC membranes in this study have potential for commercialization.

Keywords:

polycarbonate , membrane , Taguchi experimental design , phase inversion