The adsorption behavior and phase transfer catalytic fixation of a special dye SCF-AOL2 on cotton in supercritical carbon dioxide

Zhu Yang-Yang,Cui Chuang-Long,Xue Jia-Qi,Shi Mei-Wu,Xu Zi-Han,Jiang Wei,Long Jia-Jie

College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China. National scientific research base for waterless coloration with supercritical fluid (China Textile Engineering Society), Soochow University, Suzhou 215123, China. Jiangsu Engineering Research Center of Textile Dyeing and Printing for Energy Conservation, Discharge Reduction and Cleaner Production (ERC), Soochow University, Suzhou 215123, China.

Supercritical carbon dioxide (SC-CO₂) dyeing technique is a sustainable and powerful alternative method to conventional ones. However, its application in coloration of natural fibers is still limited to some degree. In this work, the uptake behavior and the build-up performance of a special dye SCF-AOL2, a new disperse reactive dye involving a potential reactive group of β-ethylsulfone sulfate, on cotton in SC-CO₂ was investigated. The effects of system temperature, pressure and duration on the dye uptake behavior were explored under different conditions with and without cosolvents. Particularly, a phase transfer catalytic method, involving series of reactions and a supposed mechanism in a supercritical fixation system was introduced initially for the special dye fixation by employing a phase transfer catalyst. The results show that the uptake behaviors of the special dye were significantly improved with temperature, pressure and duration in both pure and cosolvent involved SC-CO₂ systems. Approximate uptake saturation at 0.22 mg g^-1 against the substrate for the special dye was achieved in pure SC-CO₂ at 130℃, 20.0 MPa and 80.0 min. A significant improvement in the dye uptake behavior and adsorption values were also observed with the presence of a small amount (0.5% v/v) of the cosolvents of acetone and water in SC-CO₂, accompanied with no obvious saturation adsorption on the substrate in the utilized conditions. Moreover, the fixation efficiency and the color fastness of the uptake dye on the substrate were notably improved by employing the phase transfer catalytic fixation method. Furthermore, the dye uptake and catalytic fixation behaviors were also verified with color measurement, dye fixation efficiency, FT-IR analysis and color fastness evaluation.

https://doi.org/10.1016/j.supflu.2022.105651

The Journal of Supercritical Fluids,Volume 188, September 2022, 105651