Combination of silica sol and dyes on textiles

The embedding in sol-gel coatings can improve the fastness properties of dyes on textiles. The aim of this study is to investigate, whether it is necessary to apply dye and sol together in one step or the application of dye and sol can be performed in separate steps. For practical applications, it can be of high interest to apply sol and dye separately, because by this the fastness properties of once coloured textiles can be improved by sol-gel coatings or an uncolored sol-gel treated fabric can be dyed afterwards with higher fastness properties. For this, modified silica sols and dye molecules were applied in combination on textiles. The investigations were performed with the two triphenylmethane dyes Malachite Green and Guinea Green. These dyes were applied using four different methods - without sol, applied before or after sol treatment and together with the sol. The silica sols were applied in different concentration. It was demonstrated that the application together with the silica sol or the aftertreatment of dyed textile with silica sol lead to significant improvement of leaching fastness. Also the low bleaching fastness of the triphenylmethane dyes can be enhanced significantly.