Turmeric dyeing and chitosan/titanium dioxide nanoparticle colloid finishing of cotton fabric

摘要

The possibility of combining the finishing and natural dyeing of cotton fabric has been studied using a single-stage, paddry-cure technique, by treating it with chitosan/titanium dioxide nanoparticle colloids and turmeric dye. Different parameters have been studied to optimise the process, such as the chitosan/TiO2 nanoparticle colloid concentration, citric acid crosslinker concentration, sodium pyrophosphate catalyst concentration, dye concentration, pH, curing time, and temperature. To investigate the effects of combined treatment on the dyeing and functional properties of the treated cotton fabric, its ultraviolet protection factor, antibacterial activity, self-cleaning properties, rigidity, colour strength (K/S), fastness behaviour, nitrogen content, and wettability are determined. In addition, the cotton fabric surface is characterised using scanning electron microscopy. The samples treated with chitosan/TiO2 in the presence of citric acid exhibit excellent protection against ultraviolet radiation as well as antibacterial activity. The optimum conditions are 0.75% TiO2 (w/v), 10% dye (w/v), 2.5% chitosan (w/v), 30 g/L citric acid, 4 g/L sodium pyrophosphate, 70 degrees C drying temp. and 5 min drying time, 180 degrees C curing temp. and 2 min curing time. The results also indicate the efficiency of the treatment in improving the self-cleaning properties of the fabric. A significant improvement in the colour fastness is observed for the treated fabrics.