Improved permeation properties of polyacrylonitrile-based ultrafiltration membranes incorporated with poly(vinyl alcohol)

Abstract

Polyacrylonitrile (PAN)-based hollow fiber membranes were fabricated via a dry/wet phase inversion process with the addition of poly(vinyl alcohol) (PVA). The hollow fiber ultrafiltration (UF) membranes were prepared by varying the weight ratio of PVA:PAN in dope solution followed by investigation on the effect of PVA composition on the UF membrane properties and performance. Protein filtration experiments using bovine serum albumin (BSA) were conducted to study the permeation and anti-fouling properties of the PAN/PVA blend membranes as a function of time. It is found that PAN/PVA blend membranes showed better hydrophilicity than that of pristine PAN membrane. It is also found that the best ratio of PAN:PVA in dope solution is 85:15 in which the membrane exhibited good morphology and was able to achieve excellent pure water flux of 251.37 L/m(2) h bar and BSA rejection of 97%. Nevertheless, it must be pointed out that the presence of excessive PVA composition in dope solution could negatively affect membrane morphology and its performance. For anti-fouling performance, blend membrane prepared from PAN:PVA ratio of 95:5 demonstrated the best fouling resistant among all the membranes studied. Results showed that further increase in the composition of PVA in the PAN membrane did not necessarily enhance anti-fouling properties of UF membrane.