Synthesis, activity and characterization of textiles showing self-cleaning activity under daylight irradiation

The preparation, activity and characterization of TiO2 clusters on several of textiles are presented having a self-cleaning effect under daylight irradiation. The textile pretreatment was carried out by RF-plasma, MW-plasma or vacuum-UV irradiation. The textile upper layers are modified in such a way that negatively charged TiO2 chelating groups such as carboxylic groups are introduced by the pretreatment methods used. The pretreatments used in this study were applied in dry conditions in the absence of solvents. Also, the times employed for the cotton surface modification were short and involved reduced energy requirements. The quantitative results obtained during the discoloring of spots of wine, coffee, make up and grease indicate that the photoactivity observed on the TiO2 modified textiles upper layers strongly depends on the nature of the TiO2 used and on the procedure used to apply the TiO2 on the textile. When light is harvested directly by the TiO2, like in the case of grease stains an increased CO2 evolution was observed with respect to wine and coffee stains under similar experimental conditions on the same TiO2 loaded textile. Also, chemical spacers able to graft TiO2 on suitable functional groups of the textile and through a second link bond to the TiO2 clusters have been studied with promising results in photoactivated light induced discoloration processes. The TiO2 loaded textiles were characterized by transmission electron microscopy (TEM), by elemental analysis (EA), by X-ray photoelectron spectroscopy (XPS), by infrared spectroscopy (IR), X-ray diffraction (XRD) and by gas adsorption studies (BET). (c) 2007 Published by Elsevier B.V.