Adsorption and Desorption of Triton X-100 in Polystyrene Particles with Different Functionality

A complete adsorption study of Triton X-100 onto latexes with different functionality is presented. Three surfactant-free polystyrene latices with different chemical surface groups (sulfate, carboxyl, and amidine) were prepared. The pH of the liquid phase controls the surface charge, and hence this factor can be considered an important variable in this study. The adsorption isotherms show that an increase in the surface charge yields a decrease in the amount of adsorbed surfactant. A descriptive mechanism of the adsorption process which considers the presence of holes in the layer of adsorbed surfactant is presented for explaining the experimental results. On the other hand, the adsorption isotherms have been analyzed with two classical adsorption theories, those of Langmuir and Kronberg et al. Both theories give a good description of the results, but the latter offers more information on the adsorption phenomena. Copyright 2000 Academic Press.