SYNTHESIS OF ALUMINA GELS IN AMPHIPHILIC MEDIA

This work deals with the synthesis of alumina gels from aqueous soluti ons of aluminum chloride in the presence of cationic surfactant molecu les. The effect on the sol-gel transition of the reagent concentration s and of the synthesis temperature are first studied. The structure of the resulting wet and dried gels and the formation of liquid crystal mesophases are studied by X-ray diffraction. The thermal and structura l evolutions of the gels are then characterized by thermogravimetric a nd X-ray diffraction measurements. Finally, nitrogen adsorption isothe rms are used to investigate the porous texture of the thermally treate d materials up to the transformation into alpha-Al2O3.