| Azobenzene compounds have good photochemical properties whichcan be used in the preparation of light responsive hydrogel. Hydrogel isof easy preparation under mild conditions and good biocompatibility.Compared with other responsive hydrogel, light responsive hydrogel is offast and localized response characteristics, so it would have broadapplication prospects in optical switch, information recording andbiological materials.We designed and synthesized ten new azobenzene derivatives withortho substituents which have potential to form intermolecular hydrogenbond. Their structures were determined by FT-IR and NMR. Toinvestigate the photochemical properties of these products, UV-Visspectra, fluorescence emission spectra and the isomerization kinetic weremeasured, and the optimized molecular structures of the trans isomers and HOMO-LUMO gaps were calculated in the gas-phase at the DFTlevel with the Gaussian09package, B3LYP/3-21G basis set. The relativeisomerization rate of the azobenzene with acrylate group was muchbigger than that without acrylate group. The photostationary state of2-((4-(acryloyloxy)phenyl) diazenyl) benzenesulfonic acid was achievedin no more than1minute. Fluorescence emission of azobenzene withnitro and hydroxyl were enhanced after UV irradiation.The acrylate azobenzene and polyethylene glycol diacrylate600were copolymerized to make the light responsive hydrogel. The resultsshowed that UV light irradiation can reduce swelling ratio of the hydrogel.Ribavirin was used for drug release as it has many OH and NH2. Drugreleased quantity of hydrogel could be improved by UV light irradiationdue to the strong hydrogen bonding between SO3H and ribavirin.This paper designed and synthesized a series of new azobenzeneacrylate and investigted some factors affecting their photoisomerizationbehavior, at which base; a kind of light-responsible drug delivery systemwas developed by regulation of the hydrogel component. |
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