THE INFLUENCE OF BIMODAL MOSAIC SURFACE HETEROGENEITY ON THE SPECIFICSURFACE-CHARGE - SOLUTION PH DEPENDENCES OBTAINED BY POTENTIOMETRIC ACID-BASE TITRATION

A model of bimodal mosaic heterogeneity of solid surfaces containing n oninteracting domains with a different surface density of acid groups was used to study the effect of heterogeneity on the values of the spe cific surface charge determined by potentiometric acid-base titration. A comparative analysis was performed to reveal how this charge on hom ogeneous and heterogeneous surfaces with equal densities of these grou ps depends on the pH of the solutions of indifferent electrolytes. It was shown that the heterogeneity may affect substantially the results of titration at large ratios between the surface density of acid group s and the square root of the indifferent electrolyte concentration.