Radiation preparation of PVA/CMC copolymers and their application in removal of dyes.

Copolymer hydrogels composed of poly(vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC) was prepared by using electron beam irradiation as crosslinking agent. The copolymers were characterized by FTIR and the physical properties such as gelation. The thermal behavior and swelling properties of the prepared hydrogels were investigated as a function of PVA/CMC composition. The factors effecting adsorption capacity of acid, reactive and direct dyes onto PVA/CMC hydrogel, such as CMC content, pH value of the dye solution, initial concentration and adsorption temperature for dyes were investigated. Thermodynamic study indicated that the values the negative values of DeltaH suggested that the adsorption process is exothermic. The value of DeltaH (38.81 kJ/mol) suggested that the electrostatic interaction is the dominant mechanism for the adsorption of dyes on hydrogel.