simultaneous effect of low and high molecular weight of polyvinylpyrrolidone on the polysulfone ultrafiltration membrane

Polyvinylpyrolidone(pvp) is a favorite additive with suitable properties in membrane fabrication industry different molecular weight of pvp may has various effect on the polysulfone (psf) membrane here pvp-k90 and pvp-k25 as a high and low molecular weight polymeric additive was used in casting solution pore size measurement verified all of membranes had 30-369nm mean pore radius which determined by filtration velocity method results shown membrane containing 5wt% pvpk25 had maximum water flux and mean pore radius while membrane containing 7wt% pvp-k25 had maximum porosity precipitation rate(pr) of membranes increased by addition of pvp-k25 in casting solution so that this factor reach to maximum value for 7wt% pvp-k25 aslo rejection study demonstrated all membranes could separate pvp-k90 more than 92% while rejection of pvp-k30 was in 30% – 50%