The effects of UV irradiation in azo-derivatives

From all type of external stimuli the light rays are most commonly used because it involves only photochemical processes easily to control. One of the most studied of photochemical processes is photoisomerization groups, in particular the azobenzene groups. The azobenzene and his derivatives, known for Z(sin)-E(anti) reversible photoisomerization properties, have been extensively used as functional groups to synthesize various photosensitive compounds. The UV irradiation at different time of modified maleic anhydride - styrene copolymers with azo dye solutions were with UV light to increase the rate of Z(sin)-E(anti) isomerisation. The changes in the spectral absorption domain for azo compounds, a decrease in optic absorbance after irradiation, with a predisposition to come back at primary value was made with SECOMAMS750 UV-Vis spectrophotometer.