Surface Characterization of Amidoximated Acrylic Copolymer Membrane

Abstract

This paper shows the studies of wetting ability of polyacrylonitrile (PAN). Amidoximated polyacrylonitrile membranes are being used for the water purification purpose. Copolymerization of acrylonitrile (AN) and acrylic acid (AA) were performed at 65° C under nitrogen gas environment. Prepared membranes were fabricated into DMP and treated with hydroxylamine hydrochloride (HA) in aqueous solution at 60-80^° C. The HA concentration was varied from 1-3% (w/v) and the pH of the solution was adjusted to¹. Surface characterization of amidoximated acrylic copolymer membrane is done by using Fourier transform infrared (FTIR) spectroscopy and contact angle (CA) method. FTIR spectroscopy is used to confirm the copolymerization of poly (AN-co-AA) and chemical modification of poly (AN-co-AA)². As a result of amidoximation, the noticeable changes are slow disappearance of band at around 2243 cm^-1 which correspond to nitrile groups of AN. This indicates that CN group fraction decreases during the amidoximation process. Another favorable change is newly formed band belonging to the N-O stretching variation of amidoxime (AO) at around 929 cm^{-1 3}. Water CA measures surface hydrophilicity by measuring how much a droplet of water spreads on the surface. The amidoximated copolymers were confirmed to be more hydrophilic than the virgin membrane.