Polymeric superabsorbing composite prepared using a glow‐discharge electrolysis plasma for the removal of divalent heavy metal ions from aqueous solutions and its swelling properties

A novel polymeric superabsorbing composite was prepared using the graft copolymerization of acrylic acid (AANa, 70% neutralization with NaOH) and 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) onto the hydroxyethyl cellulose (HEC) [HEC‐ g ‐P(AANa‐ co ‐AMPS)], which was initiated by means of a glow‐discharge electrolysis plasma rather than a chemical initiator. The composite material was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). We obtained absorbencies of 2490 g g −1 for distilled water and of 109 g g −1 for 0.9 wt% NaCl solution. Results show that the maximum adsorption capacities for Ni(II), Cu(II), Cd(II), Pb(II), and Hg(II) from aqueous solution were 974.84, 975.43, 1535.52, 1970.47, and 1879.53 mg g −1 , respectively. The adsorption isotherm followed the Langmuir isotherm model very well. Adsorption kinetics results indicate that the fast adsorption rate followed the pseudo‐second‐order kinetics equations. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers