Preparation and properties of sulfadiazine Ag/polyvinyl alcohol hydrogel composites

A series of sulfadiazine Ag(SD-Ag)/polyvinyl alcohol(PVA)hydrogel composites were preparated by e-Beam irradiation combining with freeze-thawing. The influence of preparation process of polyvinyl alcohol (PVA) hydrogel on its properties was investigated. The tensile strength, elongation at break, water absorption, gel content, morphologies of the surfaces and their relationships with the mass fraction of PVA and preparation process were characterized using tensile testing machine, SEM and FT-IR.The mechanical tests show that the tensile strength of PVA hydrogel increases with the mass fraction of PVA(5%-15%). When the mass fraction of PVA is 15%, and the irradiation doses is 25 kGy, the tensile strength of PVA hydrogel is 0.023 MPa, 0.048 MPa, 0.028 MPa and the water absorption is 95%, 45%, 63%, by e-Beam irradiation alone, freeze-thawing after irradiation and irradiation after freeze-thawing, respectively, which indicate that e-Beam irradiation combining with freeze-thawing increases the tensile strength and decreses the water absorption of the PVA hydrogel. The antibacterial activity of SD-Ag/PVA hydrogel was investigated after adding SD-Ag into the PVA hydrogel. The zones of inhibition show that the antibacterial activities can be enhanced with the mass fraction of SD-Ag increasing and that the composites have higher antibacterial activity towards Gram-negative bacteria (E. coli) than Gram-positive bacteria (S.aureus).