Effects of spinning temperature on hollow fiber membrane prepared via thermally induced phase separation

In this study, isotactic polypropylene hollow fiber membranes were fabricated using co-diluent of di-n-butyl phthalate and dioctyl phthalate via thermally induced phase separation method. A coarsening model in terms of the momentum, mass and heat transfer during the spinning process was established to describe the effect of the spinning temperature on the membrane. The increasing spinning temperature increased the predicted solidification time and decreased phase separation time simultaneously. Moreover, the diluent evaporation on the outer surface is dramatically influenced by temperature. The prepared hollow fiber membranes were used to concentrate NaCl saline water of 30 up to 80 g/L about 100 h to evaluate the performance of air gap membrane distillation process in terms of permeation flux and gain output ratio. The salt rejection always exceeded 99.9% in the concentration experiment.