CHARACTERIZATION OF RHODAMINE 6G ADSORBED ONTO HECTORITE BY ELECTRONIC SPECTROSCOPY

The adsorption of rhodamine 6G onto hectorite is investigated by UV-Vis absorption and fluorescence spectroscopies. The monomer of rhodamine 6G is reported to be adsorbed onto both the external and the internal surfaces, the external adsorption being predominant immediately after the sample preparation. The metachromatic effect observed in the adsorption spectra is attributed to dye aggregation at both the internal and the external surfaces, The experimental results also suggest a tendency of the monomeric form of rhodamine 6G to be adsorbed onto the internal surface after increasing the stirring time, mainly at high clay concentrations in the aqueous suspensions. (C) 1995 Academic Press, Inc.