Dyeing behavior and mechanism of Crocein Orange G on carboxymethyl cotton fabric

Traditional cotton fiber dyeing requires an abundance of salt, which leads to environmental pollution. Consequently, decreasing or eliminating the use of salt has become the primary focus of current research. In this study, Crocein Orange G was used to dye carboxymethyl cotton. Carboxymethyl cotton has better color shades than raw cotton and it is used along with a mordant in a simultaneous-mordant dyeing process, at a pH of 7, Al₂(SO₄)₃·18H₂O as the mordant. In addition, it was found that the adsorption kinetics of carboxymethyl cotton followed a pseudo-second-order kinetic model. The equilibrium adsorption capacity increased as the temperature increased from 30 to 50 °C, and the maximum equilibrium adsorption was 8.21 mg g⁻¹ at 50 °C. Furthermore, the adsorption isotherm data exhibited good agreement with the Freundlich isotherm. These results will help achieve salt-free dyeing of cotton fabric in the textile industry.