FORMATION AND GAS FLUX OF ASYMMETRIC PMMA MEMBRANES

In the present work, PMMA membranes were prepared by wet phase immersi on methods to improve their gas fluxes. It is found that different mem brane structure can be obtained by using different nonsolvent-solvent pairs. To completely describe the membrane formation process, the nons olvent-solvent miscibility and the interfacial polymer concentration i n casting solution should be considered accompanied by the ternary pha se diagram. A simplified solution-diffusion model was developed to est imate the interfacial polymer concentration. In addition, the effects of adding solvent into the coagulation bath and adding nonsolvent into the casting solution are discussed.