Application of pigments in textile coloring has many advantages such as less water and energy consumption,
less effluent load and higher efficiency, so the pigments are perfect alternatives to dyes for
eco-friendly coloring. In this work, a stable anionic nanoscale pigment suspension was prepared using a
polymeric dispersant to color the cationised cotton with the exhaust method. Meanwhile, ultrasound was
carried out during the adsorption to evaluate the ultrasonic influences on the uptake of pigment, adsorption
efficiency and final product quality. The uptake of pigment is found to be higher with ultrasonic
method than that with conventional technique because of the good dispersing capacity of ultrasound
to pigment particles. Besides, it is found that nanoscale pigment has higher adsorption rate when using
ultrasonic method because the ultrasound promotes the diffusion of pigment through the fiber–liquid
boundary layer. Lastly, the color difference (E) reveals the nanoscale pigment can be deposited on
cotton surface more uniformly under ultrasonic condition, improving the product quality obviously.