Sustainable Bleaching Process of Raw Cotton by TiO2 Light-Activated Nanoparticles

Abstract

Nanoparticles (NPs) of titanium dioxide (TiO2) are promising for the photocatalytic degradation of organic compounds, arising as an excellent alternative to conventional bleaching processes. Within this background, aqueous suspensions of TiO2 NPs were impregnated by the pad-dry method in raw cotton. The hydrophilic properties and whiteness index (WI) of Berger were the main parameters examined before and after the TiO2 treatment. In the absence of water, using a UV-Vis lamp, high hydrophilicity was found for raw cotton. Diversely, under UV-LED radiation, the presence of water molecules in the coated cotton was revealed to be a crucial parameter in enhancing its whiteness. A comparable WI of Berger with conventional bleaching methods was obtained using 0.5 g L-1 TiO2 suspension under UV-LED radiation, suggesting that the impregnation of TiO2 NPs can be a promising alternative for the industrial bleaching methods, as it proves to be more sustainable and with low operating costs.

Application Technologies for Functional Finishing of Textile Materials

“…Nano-technology seems to be a significant alternative for achieving functional and multifunctional textile materials [35] however; in some cases, there have been still some issues of industrialization of nanoparticles because of producing them only in laboratory scale experiments. Studies about using liposomes in dyeing processes [47][48][49] photocatalytic reactions for bleaching process [50,51] and layer-by-layer self-assembly technique for producing multifunctional multilayers [52,53] have also been taken place in the literature but there has been no scientific clue reported in the literature for industrialization of these methods in textile manufactories.…”

Investigation of Bleaching of Cotton Fabrics with UV-TiO2

“…High temperatures required in H 2 O 2 bleaching increase the energy costs. In addition, peroxide bleaching effluent raises the pH value of the factory downstream and adds trace amounts of H 2 O 2 and stabilizers to it [7,8]. Energy conservation, waste control and chemical recovery became emerging issues, resulting in an increase of research for more environmentally friendly technologies.…”