Synthesis of AMIMCl/AM Copolymer Hydrogel and its Adsorption Effect on Permanganate Anion

A series of cationic poly(AMIMCl/AM) hydrogel were synthesized by solution copolymerization using 1-Allyl-3-Methylimidazolium Chloride (AMIMCl) and acrylamide (AM) as polymeric monomers. The prepared copolymers were characterized by using the FTIR spectra and TG analysis. The adsorption abilities of the prepared hydrogel were investigated for the removal of MnO4− anion from the aqueous solution. FTIR spectra and TG analysis show that p(AMIMCl/AM) hydrogel is indeed a copolymer of AMIMCl and AM. The adsorption results show that the adsorption capacities of p(AMIMCl/AM) hydrogel are affected by AMIMCl contents and p(AMIMCl/AM) with 10 wt.% AMIMCl exhibits the largest adsorption capacity. Batch equilibrium experiments were conducted to investigate the effects of pH, time, initial MnO4− anion concentration, and temperature on the adsorption of MnO4− anion on p(AMIMCl/AM). Results from kinetic experiments show that the adsorption rate of MnO4− ions onto the composite is quite fast. Adsorption equilibrium may reach within 5 min. Adsorption kinetics of MnO4− anion on p(AMIMCl/AM) follow the pseudo-second-order kinetic model. Equilibrium data was correlated with the Langmuir, Freundlich, and Temkin isotherms and generalized isotherm. The Langmuir and Freundlich isotherms show better fit to the equilibrium data than the other two isotherms.