DIFFUSION OF THE DYES, EOSIN YELLOWISH, BROMOPHENOL BLUE, AND NAPHTHOL GREEN BLUISH IN WATER ADSORBED BY MONTMORILLONITE

Abstract

The diffusion of Eosin yellowish, Bromophenol blue and Naphthol green bluish was measured and apparent diffusion coefficients were calculated. The data show that clay-absorbed water only a few molecular layers in thickness is effective in the solubilization and diffusion of the 3 dyes studied. In this respect the absorbed water is distinctly liquid-like in its behavior. Apparent diffusion coefficients calculated from Fick''s law lead to estimates of from 0.01 to 0.001 for the "transmission coefficients." The data indicate interaction between the clay, clay-absorbed water, and the diffusing species, but do not yield an estimate of the interaction coefficient. It is shown that the dissolution and diffusion of these substances occurs at water contents far below the wilting point of most plants.