Novel dye removing agent based on CTS-g-P(AA-co-NIPAM)/GO composite

A novel composite Chitosan graft poly (acrylic acid-co-N-isopropylacrylamide)/graphite oxide (CTS-g-P(AA-co-NIPAM/GO) is synthesized and used to remove methylene blue (MB) and fuchsin basic (FB) from aqueous solutions by adsorption. Small amount of GO brings about great improvement of the thermostability together with the adsorption amount. Adsorption capacities of MB and FB increase from 842.1 and 633.7 mg/g, respectively, to 1496.3 and 1000.8 mg/g, respectively, with 0.02 g intercalation amount of GO. The interactions between GO and main body of CTS-g-P(AA-co-NIPAM) graft copolymer are hydrogen and amide bonds, whereas that between dye molecules and CTS-g-P(AA-co-NIPAM)/GO composite is hydrogen bond as well as electrostatic interaction. Effect of various conditions on the adsorption capacities is discussed. Adsorption isotherms and thermodynamics are studied. The adsorption of both MB and FB are spontaneous and satisfy the Redlich-Peterson equation. Kinetic study shows that the adsorption of both dyes is in accordance with the Pseudo first-order kinetic model.