Preparation and properties of different photoresponsive hydrogels modulated with UV and visible light irradiation

Two different types of hydrogel containing azo group were designed and prepared via UV and visible light initiating photopolymerization technology respectively. The obtained two hydrogel showed different swelling properties and control release behaviors with Ribavirin as model drugs. Upon additional irradiation, they exhibited different photo response characters, which may be due to the different isomer states of azo group under different light irradiations and the interior morphology of hydrogel investigated by scanning electron microscopy (SEM).