Synthesis, characterization and swelling behavior investigation of hydrogel based on AAm and AA using CdS nanorods as photocatalyst initiator under different irradiations

Hydrogels are three-dimensional hydrophilic polymer networks which are able to swell in the aqueous environment. Acryl Amide (AAm) was photopolymerized using cadmium sulfide (CdS) nanorod semiconductor as a photocatalyst initiator without additive under sunlight, blue and green LED irradiations. The effect of different synthesis conditions such as initiator kind and concentration, cross linking agent concentration, light intensity, copolymerization with acrylic acid (AAc) and dilution (amount of water) were investigated toward the goal of maximum swelling for hydrogel. The results showed that the effect of cross-linker on the swelling is reverse but the swelling of hydrogel increases by increasing the amount of solvent and light intensity. The swelling of the hydrogels reached from 66 to the maximum amount of 650 g water/g hydrogel with the copolymerization of AAm with AAc. Swelling of the hydrogel after optimization was measuredin ionic solution and under load. Synthesized superabsorbent hydrogel was characterized by Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and transmission electron microscopy)TEM). Results showed that the lower cost, high speed reaction and high efficiency of photopolymerization lead to hydrogel and superabsorbent with high swelling property. (C) 2016 Elsevier B.V. All rights reserved.