Title : Alumina based nanomaterials
High purity alumina (HPA) is a processed premium non-metallurgical alumina product characterized by its purity level- i.e. 99.9% (3N), 99.99% (4N), and so on. Recently world demand for high purity alumina has gained incredible traction, owing to growing technological advancements and increasing demand from applications namely LED bulbs, electronic displays, automotive, and medical.
The present work focuses on preparing the α-phase of 3N pure nano-alumina from aluminum foil using an alkoxide process. The high-purity aluminum alkoxide is synthesized from aluminum foil and alcohol, and hydrated alumina is produced by hydrolysis of alkoxide, and finally, high purity alumina is obtained by calcination. XRD studies showed that α-alumina was obtained by calcining hydrated alumina at a high temperature of 1200oC after the rearrangements of oxygen packing. Ideally, the α-phase of alumina was obtained after calcination of hydrated alumina via different intermediate phases. The complete phase transition to the thermodynamically stable phase of alumina (α-phase) strictly depends on the control of hydrolysis conditions as well as uniformity of temperature distribution during calcination. Micrographs of 3N powder showed nano-size particles resulting in higher surface area and this kind of mesoporous structure could be suitable for various applications i.e adsorption and catalysis. The cost-benefit analysis for the preparation of alumina by both routes revealed that the alkoxide method proves to be an economical route to get highly pure alumina with controlled conditions of hydrolysis, drying, and calcination. Figure 1 below shows the XRD pattern of alumina powder prepared by the alkoxide route.