Wash fastness improvement of malachite green-dyed cotton fabrics coated with nanosol composites of silica-titania

Washing fastness of dyed cotton fabrics by malachite green (MG) blended with nanosols composite of SiO2-TiO2 has been significantly enhanced. The nanoparticulate inorganic sols were prepared by acid-catalyzed hydrolysis of titanium (IV) tetraisopropoxide (TTIP) and tetraethylortosilicate (TEOS) in ethanol at room temperature. The effect of silica on the characteristics of nanosols composite of TiO2-SiO2 was studied. Nanosols morphology was examined by transmission electron microscope (TEM). The nanosols silica-titania composite showed homogeneous morphology of interconnected spheres of about 20–25 nm. Enhanced dye absorption was observed at nanosols with silica content. The reflection spectra of the samples before and after leaching test using sodium dodecyl sulphate were recorded. The results showed that embedding TiO2-SiO2 and SiO2 sols into the MG dye can improve the wash fastness by 40–95%. The highest improvement was obtained by SiO2-MG-coated cotton fabrics as well as composites of SiO2-TiO2-MG-dyed cotton fabrics at highest silica content. The MG-nanosols composite silica-titania dyed cotton fabric has also shown remarkable antibacterial activity over Staphylococcus aureus and Escherichia coli.