Investigation on the liquid phase diffusion of an acid dye in aqueous solution by employing a novel diaphragm cell method

In order to investigate and enhance the diffusion process of dyes to fiber, the liquid phase diffusion behavior of the C.I. Acid Red 134 (AR-134) dye was investigated by employing a novel diaphragm cell method. The effects of process factors on the dye liquid phase diffusion properties were systematically discussed and a theoretical model of the relationship between diffusion coefficient and process factors was established. Meanwhile, an Arrhenius model and a polynomial model were established to explore the relationship between temperature, concentration of the dye, and liquid phase diffusion coefficients of the dye. Moreover, the isothermal diffusion rate curve of the dye was built, and liquid phase diffusion dynamics of the dye were illustrated. The results indicate that in order to improve the dye liquid phase diffusion properties, the flow rate and temperature should be properly increased, and the concentration of Peragal O and sodium sulfate should be decreased. Meanwhile, the relationship between dye liquid phase diffusion coefficients and temperature conforms to the Arrhenius equation under the same concentration of the dye. In addition, dye liquid diffusion coefficients at the same temperature can be expressed as concentration polynomials. Particularly, the liquid phase diffusion behavior of the dye was more consistent with a quasi-first-order kinetic model and was not controlled by a chemical adsorption mechanism. The obtained results supplemented traditional dyeing theories on the liquid phase diffusion process of acid dyes, providing an application foundation for new ideas and methods in the research and development of green and high-efficiency dyeing technology.