PREPARATION OF NONWOVEN-FABRIC REINFORCED POLYACRYLONITRILE MF MEMBRANES BY PHASE-INVERSION METHOD

Polyacrylonitrile (PAN) MF membranes were prepared by phase inversion from dimethyl sulfoxide solvent into water, using polyester nonwoven fabrics as the support material. Three kinds of methods for coating nonwoven fabrics with a PAN dope were tested: casting, saturation and ultrasonic-saturation. The ultrasonic-saturation membrane was found to be excellent in structural stability and reproducibility, and the particle retention of the membrane could be controlled by the PAN-dope concentration and the gelation temperature. The laboratory-made PAN membrane was almost symmetric, with a pure-water flux higher than that of commercial MF membranes when the pore size was less than 0.1 mum.