Effect of Preparation Conditions on Morphology and Performance of Hemodialysis Membranes Prepared from Polyether Sulphone and Polyvinylpyrrolidone

Flat-sheet hemodialysis membranes were prepared with 12% (wt) polyether sulphone (PES) and 2.8% (wt) polyvinylpyrrolidone (PVP) dissolved in dimethylacetamide (DMAc) by phase inversion method. The performances of membranes were investigated on the basis of direct removal of uremic toxins from blood serum. The membranes were put in contact with human blood serum in a batch dialyzer instrument and removal of urea, uric acid and creatinine were measured in a medical laboratory according to the standard methods. The effects of temperatures of coagulation bath and polymer solution on membrane morphology and hemodialysis performance were investigated. The SEM micrographs showed typical asymmetric channel-like structures, which their sizes and numbers change with different preparation conditions. Membrane structure depends on the diffusion rate of solvent and non-solvent molecules in the coagulation process. The temperatures of polymer solution and coagulation bath are among the most important parameters of the coagulation processes. The performance and morphology studies of hemodialysis membrane indicated that by increasing the temperature difference between coagulation bath and polymer solution temperatures, the sizes of channel- like structures were increased. A removal of 84% urea, 71% uric acid, and 53% creatinine was attained by a membrane prepared at 60°C coagulation bath and 23°C polymer solution temperatures. The L929 fibroblast cell culture test on PES membranes showed excellent biocompability.