No abstract

The effect of the tail length of Triton-X surfactants on the surface properties of ceria prepared by means of reversed micelles and Ce(O i Pr) 4 has been systematically studied. Generally, solids with increased surface areas (up to 136 m 2 g À1 ) were synthesised. It was shown that the tail length strongly affects the surface characteristics. Further studies were carried out using UV-Vis, ATR-FTIR, XRD and TGA/DSC studies of the precursor gels as well as N 2 -isothermal adsorption BET, XRD, FT-IR, UV-Vis diffuse reflectance and SEM investigations of the final solids samples. An interaction mechanism between the ceria precursor molecules and the polar tail of the reversed Triton X micelles and the formation of ceria (CeO 2 ) particles in the aqueous nucleus of the reversed microemulsions is proposed.

Nanoporous titania was prepared from non-ionic surfactant reverse micelles (e.g. Triton-X) and the effects of the chain length of the surfactants and calcination temperature of the precursor gels on the surface properties of the product (mesoporous titania) were investigated. The studies included sample characterization of the precursor gels from the titania samples characterized by UV-Vis, ATR-FTIR, XRD, TGA/DSC and the titania samples by N 2 -adsorption BET, XRD, FT-IR, UV-Vis diffuse reflectance and SEM measurements after calcination at 400 C, 500 C, 600 C, 700 C and 800 C. According to the experimental results, generally increasing the length of the polar tail of Triton-X results in an increased specific surface area and volume, and an average pore diameter of the solids. Moreover, increasing the length of the polar tail is associated with a smaller crystallite size and higher thermal stability of the materials. Finally, a nucleation mechanism of the titania particles within the aqueous centre of the reversed micelles is proposed.

No abstract

No abstract