Thermal analytic study of the adsorption of acridine orange by smectite minerals

DTA, TG and DTG curves of montmorillonite and laponite treated with various amounts of acridine orange, were recorded in air, simultaneously with EGA curves of H₂O, CO₂, NO₂, CH₃ and C₂H₆. The thermal analysis curves could be divided into three regions representing dehydration of the clay, oxidation of the organic cation and dehydroxylation of the clay. The oxidation region showed two exothermic peaks representing the oxidation of H and C of the organic matter, respectively. Thermal analysis curves of laponite differred from those of montmorillonite. The profile of EGA curves of laponite did not change with the degree of saturation of the clay by the dye whereas those of montmorillonite were affected by the degree of saturation.