An environmentally friendly bleaching process for cotton fabrics: mechanism and application of UV/H2O2 system

Hydroxyl radical is the main reactive species in hydrogen peroxide (H2O2) bleaching of cotton fabrics. Ultraviolet (UV) irradiation of the H2O2 bleaching system can efficiently produce hydroxyl radicals (HO·) under neutral or alkaline conditions, which were proven experimentally and theoretically by computational modeling. Various UV/H2O2 bleaching routes were screened to obtain desired whiteness index and acceptable bursting strength of the bleached fabrics. The optimal properties of the bleached cotton knitted fabric could be obtained at UV irradiation of 312 nm on the fabrics with a hydrogen peroxide solution under alkaline conditions.