Characterization and metal sorption of polyacrylamide/chitosan nanocomposite hydrogels synthesized by gamma radiation.

Abstract

Gamma irradiation was used to prepare nanocomposite hydrogels composed of polyacrylamide (PAM) and chitosan nanoparticles (CS-NPs). The hydrogels were investigated by FT-IR spectroscopic analysis, thermogravimetric analysis (TGA) and the measurements of swelling in water. The metal sorption and kinetics for Cu +2 , Pb +2 and Fe +3 metal ions was investigated. The results of TGA analysis showed that the PAM/CS-NPs hydrogels had lower thermal stability than PAM hydrogel. It was found that PAM and PAM/CS-NPs hydrogels reached the equilibrium swelling in water at 4 hours. However, PAM/CS-NPs hydrogels displayed higher swelling in water than PAM hydrogel. The metal sorption study showed that PAM/CS-NPs nanocomposite had high affinity and selectivity for the metal ions according to the order: of Cu +2 > Pb +2 > Fe +3 . On the other hand, the sorption by the hydrogel networks is controlled by applying Fick's law.