| Abstrakt: |
So-called sdvanced oxidation involves the generation of free radical hydroxy species. Ozone, a highly unstable compound, liberates such radicals, which can be used for bleaching. In this work grey cotton fabric was bleached with an ozoneoxygen gas mixture, and the effects of ozone concentration and treatment time on the properties of the bleached fabric were studied. The properties evaluated were whiteness index, strength, elongation, extent of impurities (size and wax) removed, degree of chemical modification (carboxyl and aldehyde groups) and reactive dye take-up. These properties were compared to those from conventionally bleached materials (acid desize-scour-peroxidecalcium hypochlorite bleach). The results show that an acceptable degree of whiteness (ready for dyeing) can be obtained by ozone bleaching in a very short time. This process is environmentally acceptable because it is does not use harmful chemicals, it requires a very low quantity of water, and bleaching is achieved in a very short time at room temperature. |
