Thesis (M.Eng.)--Chulalongkorn University, 2008

Alumina doped with zinc oxide and alumina doped with titania were synthesized by sol-gel method in alcohol solution. Aluminum sec butoxide were used as an aluminum precursor for synthesis of final product. Effect of molar ratio between ethylacetoacetate (EAC) and nitric acid were investigated for preparing clear homogeneous solution. All particulate powders were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) to identify phases, particle size and chemical composition of their synthesize material. It was experimentally found that a preparation of alumina doped with zinc oxide by calcination at temperature 400C, resulting in a crystalline transformation of alumina doped with zinc oxide to zinc aluminate (ZnAl2O4). While, crystalline alumina doped with titania could be prepared by calcination at temperature over 800C. These synthesized products exhibit hydrophilic property because aluminum hydroxide (Al(OH)3) could be combined with zinc hydroxide (Zn(OH)) and titanium hydroxide (Ti(OH)4) in hydrolysis reaction to become compounds of alumina and zinc as well as alumina and titania in condensation process. As a result, zinc aluminate (ZnAl2O4) and aluminum titanate (Al2TiO5) were obtained by sol-gel method.