Photoinduced decolorization of 2, 6-dichloroindophenol by 2-anthraquinone sulfonate treated nylon

Photoactive 2-anthraquinone sulfonate sodium (2-AQS) can produce hydroxyl radical and other reactive oxygen species under UVA irradiation. Because of its acid dye like feature, 2-AQS was immobilized onto nylon fibers through an acid dyeing process, and the dyed nylon was employed as a photoactive self-cleaning material. As a model study, decolorization of representative colorants such as 2,6-dichloroindophenol (DCIP) by the material was investigated. The results revealed that DCIP was first absorbed on the fibers and then degraded by hydroxyl radicals and other reactive oxygen species generated by 2-AQS on the surfaces upon UVA exposure. The photo degradation pathway of DCIP was further studied by directly using aqueous 2-AQS solution, and the degraded products in the solutions were analyzed by LC-MS. Different light sources and hydrogen donors were investigated in degradation of DCIP. The photoactive functions on the 2-AQS-dyed nylon fibers were quite durable and maintained similar decolorization effect of DCIP after five repeated tests.