Abstract: A conbination of flow-apparatus and a numerical model for simulating diffusion with a reaction on intersurface of droplets which were dispersed in a gelatin layer was employed for investigating the kinetic process of the reaction of dispersion DIR(Ⅰ)and DIAR(Ⅱ) coupler with QDI respectively in gelatin layer. The results showed that the kinetic curves obtained from both the experiments and the numerical model were in good agreement.This suggested that the reaction took place dominantly at the interface between droplets and gelatin-aqueous solution and that the reaction rate was dependent on the size of droplets, specific rate constant, concentrations of coupler in the organic medium and of QDI on the intersurface of droplets, which was also related to the diffusion coefficient of QDI in the gelatin layer. The specific rate constants of reaction of DIR(Ⅰ) and DIAR(Ⅱ)coupler with QDI were obtained respectively.

Key words: chemical kinetics, DIR(DIAR) coupler, coupling reaction, color image formation