Influence of the surface potential on interfacial kinetics

The initial mass-transfer rate of acetic acid from the aqueous to the organ ic phase with tri-n-octylamine and toluene as solvents has been studied in a constant interfacial cell as a function of the stirring speed, concentrat ions of the transfer species, and chemical adsorption layers. For a detaile d understanding of the mass-transfer process, the electrophoretic mobility of oil-in-water droplets with different interfacial charges has been measur ed with a ZETA sizer as a function of the pH value. It could be proven that a change of the interfacial charge influences the xi potential of the disp ersed oil drops and thus the mass transfer of the acetic acid. A,kinetic mo del and its electrostatical extension is introduced to describe the interfa cial reactions and mechanism, when using a thermodynamic-consistent activit y coefficient model.