The removal of heavy metal ions from aqueous solutions by novel pH-sensitive hydrogels

Novel non-ionic hydrogels were synthesized by radical homopolymerization of N-vinyl-2-pyrrolidone (VP) or by radical copolymerization of VP with methylacrylate (MA). A macroinimer (MIM) was used as a crosslinker and initiator, as well. The percentage of mass swelling ratios (S-M), the molecular weight between crosslinks (M-c) and Young's modulus of the hydrogels were investigated. The hydrogels were used as binding materials for different heavy metal ions such as Cu2+, Cd2+, Ni2+ and Zn2+ under varying conditions. The binding capability of the hydrogels toward the metal ions decreases in the following order: Cu2+ > Ni2+ > Zn2+ > Cd2+. (C) 2010 Elsevier B.V. All rights reserved.