Salt-free clean dyeing of cotton fabrics by reactive dye/cationic nanoparticle to obtain dark-coloured fabrics

The conventional dyeing processes employed to obtain dark-coloured fabrics necessitate the utilisation of substantial quantities of dyes, a limitation that is further compounded by the existence of dyeing saturation. To address these issues, a novel reactive dye/cationic nanoparticle is proposed. The effects of the synthesis process of reactive dyes/cationic nanoparticle on particle size, zeta potential, dispersion stability and K/S value were investigated. Furthermore, an investigation was conducted into the effect of cationic nanoparticle structure on the dye absorption of reactive dyes/cationic nanoparticles. In addition, the mechanism by which cationic nanoparticles enhance dye absorption and achieve a deep color effect was elucidated. The dyeing results demonstrated that at a constant reactive dye concentration, the K/S value of the fabric dyed with reactive dye/cationic nanoparticles was 10.12. This was 35 % higher than the reactive dye-only process, showing a pronounced deepening effect. This paper demonstrates the efficacy of a green and environmentally-friendly dyeing process that produces a deep color effect with minimal dye dosage and without salt, providing a theoretical foundation for the subsequent design of efficient darkened reactive dye/cationic nanoparticles.