Abstract
Fine particle synthesis using tubular flame combustion allows efficient use of combustion energy and highly accurate control of particle morphology and composition by temperature and gas concentration. In this study, we investigated the addition of energetic materials to precursors to improve the heating efficiency and increase the specific surface area of alumina particles in tubular flames. The addition of ammonium nitrate (AN) to the precursor resulted in irregular particles with flake-like or concave surfaces. The particles were deformed by the large amount of gas generated by the decomposition and combustion of AN in the flame field. Furthermore, the addition of urea to the precursor increased heat generation and the percentage of the high-temperature α-alumina phase. The gas adsorption results showed that the specific surface area of fine alumina particles prepared with the addition of energetic materials increased up to 2.6 times compared to that obtained without energetic materials (118 m2･g-1).
