Controlled synthesis of alumina using trialkylaluminum as starting materials

Abstract

Morphologically controlled production of nanomaterials is very important in material chemistry because of the strong influence of materials' structure on their characteristics. In this paper, alumina with various morphologies were synthesized using Me₃Al and Et₃Al as starting materials. Aluminum trialkyls were transformed into precursors upon exposure to air with relative humidity of 0–90% and then thermally decomposed yielding white alumina powders. Depending on the starting R₃Al and conditions of precursor synthesis, aluminum oxide was obtained in the form of separated or agglomerated spherical nanoparticles, porous sponge-like material, worms- and wool balls-like particles. Structural data such as specific surface area, average particle size and average pore size of alumina obtained from Me₃Al were significantly different than those of alumina synthesized from Et₃Al. This simple method allows for the production of aluminum oxide without any traces of other metals, which is important for application in electronics. The reaction course of R₃Al with dioxygen and air moisture and composition of alumina precursors have been discussed.