Bleaching Cotton Fabric with Electrogenerated Oxygen--The Role of Hydroxyl and Superoxide Radicals

摘要

Many active oxygen species, especially the hydroxyl radical, may play an important role in damaging cotton fabric treated at a Pt electrode with electrogenerated oxygen. To elaborate the mechanism of this damage, we have investigated the generation of hydroxyl and superoxide radicals in electrolysis and used the oclorimetric thiobarbituric acid and epinephrine spectrophotomtric method, respectively, for detection. Generation of hydroxyl radicla during electrolysis is confirmed at a Pt anode but speroxide radical is not. The electro-oxidation reactions for some model carbohydrates indicate nearly the same behavior as that with Fenton's reagent. Apparently, cotton fabric damage occurs through a reaction with a hydroxyl radical that is formed on the surface of the electrode, being initiated by the abstraction of a hydrogen atom from a cellulose molecule by the hydroxyl radical.