Reactive dyeing of cotton in water-organic solvent mixture

Cotton fabric was dyed with a reactive dye in water/dichloromethane two-phase immiscible solvent media. In order to minimize dye loss due to its hydrolysis, the reactive dyeing was carried out in dichloromethane containing a small amount of water. With only 2 mL of water in 23 mL of dichloromethane, 1 g of cotton fabric could be dyed perfectly. The uptake ratio increased greatly compared with that of normal reactive dyeing in a water medium. It would seem that the hydrophobic solvent, dichloromethane, can assist the even dyeing as it disperses a small amount of dye-dissolved water phase and conveys this water phase to the fabric entirely and uniformly.