Thermal degradation of (zinc-aluminium-layered double hydroxide-dioctyl sulphosuccinate) nanocomposite

Zinc-aluminium-layered double hydroxide containing dioctyl sulphosuccinate in the lamella for the formation of an organic-inorganic layered hybrid nanocomposite (ZALDIN) was synthesized by spontaneous self-assembly of organic and inorganic components from an aqueous phase. The heat-treated ZALDIN (ZALDITs) was obtained by heating ZALDIN at 150-800 degreesC under atmospheric pressure. The layered structure of the nanocomposite collapsed when the sample was heated at 150-250 degreesC. The formation of ZnO phase was observed when ZALDIN was heat-treated at 250 degreesC or higher, and in addition. a ZnS phase was also observed when the sample was heat-treated at 800 degreesC. The ZnO phase became more prominent as the heating temperature increased. The specific surface area for ZALDITs generally increased with temperature, with an optimum of about 62 m(2)/g at 600 degreesC. However, the surface area decreased to 39 m(2)/g at 800 degreesC, compared to 4 m(2)/g for ZALDIN. (C) 2002 Elsevier Science B.V. All rights reserved.