Water retention and dye adsorption behavior of Gg-cl-poly(acrylic acid-aniline) based conductive hydrogels

Publication date: November 2014
Source:Geoderma, Volumes 232–234
Author(s): Kashma Sharma , B.S. Kaith , Vijay Kumar , Susheel Kalia , Vinod Kumar , H.C. Swart
Investigation on water retention and dye adsorption behavior of Gg-cl-poly(acrylic acid-aniline) conducting hydrogel has been studied. In this study, a novel poly(acrylic acid-aniline)-grafted gum ghatti based conducting hydrogel were synthesized by a simple two-step method. Initially, superabsorbent copolymers based on acrylic acid and gum ghatti was prepared using N,N′-methylene-bis-acrylamide and ammonium persulfate as a cross linker-initiator system under microwave irradiation. Optimum reaction conditions affording maximum percentage swelling were: solvent=10ml, acrylamide=0.291×10⁻³ molL^–1, ammonium peroxydisulfate=0.291×10⁻³ molL^–1, N, N′-methylene bisacrylamide=0.324×10⁻¹ molL⁻¹, reaction time=55s, microwave power=100% and pH=7.0. The effect of different reaction parameters on the swelling capacity was investigated. In the final step, polyaniline was entrapped within a crosslinked hydrogel followed by doping with hydrochloric acid (HCl), which led to the formation of conducting hydrogel. The IPN has been observed to exhibit as much as 2032% swelling in aqueous solution. Synthesized hydrogels were analyzed using FTIR, XRD, SEM and TGA. Application of hydrogels to improve the water retention properties of different soils was studied and found that the IPN hydrogel can improve the moisture retention capacity of soil for cultivation. Finally, synthesized hydrogels was studied for dye removal from waste water. It has been found that IPN hydrogel shows better adsorption behavior than semi-IPN.