Bleaching cotton fabric with electrogenerated oxygen - The role of hydroxyl and superoxide radicals

Many active oxygen species, especially the hydroxyl radical, may play an im portant role in damaging cotton fabric treated at a Pt electrode with elect rogenerated oxygen. To elaborate the mechanism of this damage, we have inve stigated the generation of hydroxyl and superoxide radicals in electrolysis and used the colorimetric thiobarbituric acid and epinephrine spectrophoto metric methods, respectively, for detection. Generation of hydroxyl radical during electrolysis is confirmed at a Pt anode but speroxide radical is no t. The electro-oxidation reactions for some model carbohydrates indicate ne arly the same behavior as that with Fenton's reagent. Apparently, cotton fa bric damage occurs through a reaction with a hydroxyl radical that is forme d on the surface of the electrode, being initiated by the abstraction of a hydrogen atom from a cellulose molecule by the hydroxyl radical.