KINETICS AND MECHANISM OF DYEING PROCESSES - THE DYEING OF COTTON FABRICS WITH A PROCION-BLUE DICHLOROTRIAZINYL REACTIVE DYE

The kinetics of the dyeing of a dichlorotriazinyl-reactive dye, Procio n Blue MX-R, with knitted cotton fabrics have been studied using a ver satile technique based on a spectrochemical channel flow cell, A mecha nism is derived where the simultaneous hydrolysis of the dye molecules , the physical binding of the hydrolyzed form, and the chemical fixati on of the active form onto the fabric are taken into account. It is sh own that the dye fixation to the fabric is controlled by a solid-liqui d interfacial process that is first order with respect to the surface concentration of dye; however, the rate of this reaction is governed b y the availability of sites for the adsorption of dye molecules on the fabric surface, Dyeing experiments are performed over a wide range of initial dye concentrations; supporting electrolyte concentrations and the kinetic parameters are reported, Atomic force microscopic studies indicate that mercerization pretreatment provides a disordered fiber surface which may offer additional sites for dye adsorption. (C) 1997 Academic Press.