Application of AAm/APTAC hydrogels and semi-interpenetrating polymer networks including of PVA in uptake of anionic dye from aqueous solutions

A series of novel hydrogels acrylamide(AAm)/(3-acrylamidopropyl) trimethyl ammonium chloride (APTAC) and semi-interpenetrating polymer networks (semi-IPNs) composed of poly(vinyl alcohol) (PVA) and random copolymers AAm/APTAC were prepared by free radical polymerization in aqueous solution. Ammonium persulfate/N,N,N',N'-tetramethylethylenediamine was used in polymerization as redox initiating pair in presence of 1,4 butanediol dimethacrylate and ethylene glycol dimethacrylate as crosslinkers. Fourier Transform Infrared Spectroscopy was used to identify the presence of different repeating units in the hydrogels and semi-IPNs. Scanning Electron Microscopy images were taken for determination of surface porosity of hydrogels and semi-IPNs. Swelling experiments were performed in water at 25 degrees C, gravimetrically. The hydrogel systems that synthesized in this study were showed high water absorbency. Water and dye adsorption properties of AAm/APTAC hydrogels and AAm/APTAC/PVA semi-IPNs were investigated as a function of chemical composition of the hydrogels. An anionic dye, calconcarboxylic acid was used in sorption studies. This study also gives the quantitative information on the swelling and sorption characteristic of AAm/APTAC hydrogels and AAm/APTAC/PVA semi-IPNs for many potential applications.