A. Elsherbiny, T. Fayed
Jul 1, 2010
Citations
0
Influential Citations
5
Citations
Journal
Journal of Physics and Chemistry of Solids
Abstract
Abstract The adsorption of 2-(4′-dimethylaminostyryl)benzoxazole (DMASBO) and its benzothiazole analogue (DMASBT) onto Na-montmorillonite (Na + -MMT) was studied. The adsorption data have been fitted with Freundlich and Dubinin–Radushkevich ( D – R ) equation to find the characteristic parameters of each model. From D – R isotherm, it was concluded that the adsorption is of chemical nature. The equilibrium adsorption constant, K c , was determined and has been used to calculate the enthalpy and entropy of the adsorption process. The mechanism of the adsorption has been investigated by fluorescence, IR, X-ray and ESR spectroscopic measurements. These measurements indicate oxidation of the styryl dyes by the Lewis acidic sites of the clay and formation of radical cations at Na + -MMT surface without intercalation into the interior.