SURFACE MODIFICATION OF ACRYLONITRILE COPOLYMER MEMBRANES BY GRAFTINGACRYLAMIDE .1. INITIATION BY CERIC IONS

Surface modification of membranes of an acrylonitrile copolymer (PAN) containing 5.5% methyl methacrylate (MMA) and 4.0% sodium methylpropyl enesulfonate by grafting acrylamide (AAm) with cetric ammonium nitrate as initiator in the aqueous medium has been studied. Results showed t hat the extent of grafting was varied with some parameters, such as di methyl formamide and Tween-20 amount in the reaction solution, concent ration of AAm, and reaction time. The grafted copolymer was verified b y infrared spectra and X-ray photoelectron spectroscopy. Both of these methods also showed that the ester group of MMA unit on the surface o f PAN membranes may be partially hydrolyzed into carboxyl group in the copolymerization condition. Surface and pore structures of PAN membra nes after grafting were viewed under a scanning electron microscope (S EM). From SEM photos we know that AAm homopolymer branches were grafte d onto the surface of the membrane and the morphology of membrane did not change. Results of contact angle of isooctane on the membrane unde r water showed that the wettability of the modified membrane was impro ved. (C) 1997 John Wiley & Sons, Inc.