Abstract
The preparation of asymmetric polyethersulfone (PES) membranes by the phase inversion process was investigated. Interactions among the polymer, solvents and gelating solutions were also investigated to determine the suitable solvent and gelating solution on the basis of the physicochemical criteria. For such purpose, viscosity change of the polymer solutions in dissolution process of the polymer, mixing heat of a solvent and a gelating solution, effusion rate of a solvent from a casting solution in gelation process, and gelation point were measured, respectively. The results obtained from those physicochemical measurements and membrane preparation experiments showed that NMP was suitable for the solvent and ethanol for the gelating solution.
The membrane prepared from the casting solution composed of 30 wt% polyethersulfone and 70 wt% NMP, using ethanol as a gelating solution by the phase inversion process exhibited the separation factor α (CO2/CH4) of 40 with the CO2 flux of 1.1×10-6 [cm3 (STP) /cm2·sec·cmHg].
