High flux PEO doped chitosan ultrafiltration composite membrane based on PAN nanofibrous substrate

Abstract

A new method for fabrication of thin film nanofibrous composite (TFNC) ultrafiltration membrane with high flux containing a hydrophilic poly(ethylene oxide) (PEO) doped chitosan (CS) barrier layer and polyacrylonitrile (PAN) nanofibrous substrate was proposed in this study. First, PEO doped CS barrier layer was electrosprayed onto electrospun PAN substrate layer. Then, the deposited PEO doped CS layer was swollen to imperceptibly merge into an integrated barrier layer by acetic acid vapour treatment and chemically cross-linking in glutaraldehyde acetone/water solution to form a thin barrier film on the PAN substrate. The depositing time of electrospray and vapour treatment conditions were optimised to control the thickness of PEO doped CS layer. Oil/water emulsions system was used to evaluate the filtration performance of the as prepared composite membrane. It was shown that the TFNC membrane can perform well in the filtration of oil/water emulsions with permeate flux of 117·2 L m−2 h−1 and rejection rate of 99·0% at low pressure(0·2 MPa), and this membrane also exhibit good pressure resistance, for it showed higher flux (223·5 L m−2 h−1) with a high rejection rate (99·5%) at high operating pressure (0·6 MPa).