The adsorption and oxidation of benzidine by montmorillonite and alumina pillared montmorillonite

The interaction of montmorillonite(non pillared clay) and alumina pillared montmorillonite(Al PILC) with benzidine results in the formation of colored complexes of benzidine blue and benzidine yellow. The amount of adsorbed benzidine from an aqueous solution of benzidine dihydrochloride was measured quantitatively on the clay and the Al PILC.Under conditions of controlled pH, the amount of adsorbed benzidine by both substrates increases as the pH of the solution and the amount of added benzidine increase. The amount of adsorbed benzidine by the pillared clay is less than that on the non pillared clay under the same reaction conditions.The thermal properties of the colored complexes of benzidine with the clay and the pillared clay were measured by TGA, and their structural characteristics were examined by DRIFT spectra. From these data, the differences between benzidine blue and benzidine yellow complexes were discussed.