Preparation Of Alumina Hollow Spheres Hydrothermal And Hard Template-Assisted

Inorganic micro/nano hollow spheres are of a high strength, light weight, big surface area, heat and corrosion-resistant and many other properties, so their applications are very wide; and alumina also has a variety of excellent physical and chemical properties, such as with a small thermal expansion coefficient, high hardness, high strength, strong and stable structure. Alumina hollow spheres possess the advantages of these two at the same time, so prospects are very impressive. For this reason, the preparation method of alumina hollow spheres on this paper was studied. Aluminum nitrate salts and glucose are used as starting materials, and alumina hollow spheres were successfully prepared by using a combined process of hydrothermal and hard template techniques. The samples were analyzed and studied by transmission electron microscopy(TEM), scanning electron microscopy(SEM), X-ray diffraction(XRD), energy dispersive X-ray, (EDX) and thermal gravimetric analysis(TGA). Major work and conclusions are as follows:1,One-step process:in situcatalytic polymerization-absorption(CPA) method are explored for the fabrication of hybrid aluminum/carbon microspheres, and then subsequent oxidation removal of carbonaceous saccharide template gives rise to alumina hollow spheres through division calcined. Experimental results show that one-step method is simple and quick, but the structure of products is loose, and it has poor dispersion, and the particle size is in the micron level. We explore the mechanism of glucose polymerization processes and the formation mechanism of alumina hollow spheres.2,Two-step process:noncatalytic polymerization-adsorption(NPA) method are explored for the fabrication of hybrid aluminum/carbon microspheres. Subsequent oxidation removal of carbonaceous saccharide template gives rise to alumina hollow spheres through division calcined. The experimental results showed that alumina hollow spheres, which were prepared by two-step process, had a stable, dense and uniform hollow core-shell structure, the particle size is in the sub-micron level. The growth mechanism of the alumina hollow spheres synthesized is analyzed and discussed.3,Octylamine template and ammonia precipitation method in the two-step process are investigated and proved unworkable.