HYDROGELS OF GELATIN-SODIUM CARBOXYMETHYL CELLULOSE - SYNTHESIS AND SWELLING KINETICS

Hydrogels of gelatin crosslinked with glutaraldehyde and sodium carbox ymethyl cellulose (NaCMC) of several compositions were prepared. The s welling kinetics as a function of composition, temperature, pH, and io nic strength was studied. The rate of swelling and equilibrium swellin g were found to depend on the NaCMC content in all cases. The equilibr ium swelling increased with the temperature. The gels, which were weak ly acidic, registered increased swelling at higher pH. Swelling was su ppressed in aqueous salt solutions. In agreement with predictions of t he Donnan theory, swelling in monovalent salt solutions is greater tha n in divalent salt solutions.