ADSORPTION OF RHODAMINE 6G ON SAPONITE - A COMPARATIVE-STUDY WITH OTHER RHODAMINE 6G-SMECTITE AQUEOUS SUSPENSIONS

Absorption and fluorescence spectroscopies are applied to study the ad sorption of rhodamine 6G on saponite in aqueous suspensions. The inter pretation of the experimental results suggests that the dye can be ads orbed as the monomeric and the dimeric forms on both the external and the interlamellar surfaces of the clay. A mechanism for the adsorption is proposed on the basis of the evolution of these species with the s tirring time and the relative dye/clay concentration. The present resu lts are compared to those previously reported for the adsorption of rh odamine 6G on laponite, montmorillonite of Wyoming, and hectorite in a queous suspensions, and the effect of the nature of the clay and the p article size is discussed.