Morphology, photocleaning and water wetting properties of cotton fabrics, modified with titanium dioxide coatings synthesized with plasma enhanced chemical vapor deposition technique

Abstract

A modification of textile material with a titanium dioxide coating, applied with the help of radio frequency plasma enhanced chemical vapor deposition (RF PECVD) technique, is reported. In this procedure, titanium (IV) chloride was used as a source of titanium, oxygen was supplied in the form of O2 gas, and a cotton fabric served as a substrate. Coating morphology was studied using scanning electron microscopy (SEM), with images of each sample being recorded three times: directly after deposition (a), following routine washing with a detergent solution (b) and after eighteen month long storage under ambient conditions (c). SEM studies reveal a strong dependence of the coating quality on the RF power of deposition. This parameter of plasma-chemical modification of the fabric also substantially affects its mechanical properties.The photocleaning effect of the coatings was studied by following the changes of color intensity of stain spots of red wine, red beet juice and methylene blue dye on the fabrics, during their illumination with ultraviolet (UV) light. Similarly to the coating morphology, the intensity of this effect substantially depends on the RF power of deposition.Finally, water wettability of the investigated materials was studied using a qualitative contact angle analysis. The results show that, following its deposition with a TiO2 film, a hydrophilic cotton fabric becomes strongly hydrophobic. However, when illuminated with UV light, the water wetting properties of the TiO2 coated material return to highly hydrophilic (superhydrophilic effect).