Hydrogels based on a three component system with potential for leaching metals

In this paper, new biodegradable hydrogels were prepared, characterized and evaluated for metal ions absorption capacity from aqueous systems. The hydrogels are based on reaction of chitosan with polyvinyl alcohol, chitosan and polyvinyl alcohol with glutaraldehyde, N,N′-biisomaleimide, and N,N′-biisophthalimide under different reaction conditions to give the corresponding hydrogels P-C(I), P-C-G(II), P-C-B (III), and P-C-P(IV). The new hydrogels were characterized by FTIR spectroscopy, thermal stability, morphology, crystallography, solubility and swelling ratio. This preliminary investigation of the metal ion entrapment efficiency of the hydrogels showed that chitosan–polyvinyl alcohol–N,N′-biisophthalimide [P-C-P(IV)] hydrogel recovered Cu2+ ions with efficiencies reaching 52.5%, and for Co2+ ions 72.5% from aqueous solution systems.