Combustion synthesis of non-agglomerated A1₂O₃ and TiO₂ nanopowders in uniform electric fields

This paper presents some results on A1₂O₃ and TiO₂ nanoparticles produced using an axisymmetric stagnation-point premixed flat flame from corresponding organometallic vapor precursors. In our setup, along with the thermophoretic effect, the major mechanism that controls the rate of particle deposition on the substrate is the electrophoretic effect, which originates due to the response of nanoparticles, charged by the combustion process through thermionic emission, in a uniform electric field. The effect of electrical field strength and direction on aggregate size, crystallinity, primary particle size, and surface area, were examined using DLS, XRD, TEM, and multi point BET nitrogen adsorption, respectively. Additionally, the Sandia Spin code was used to calculate the gas-phase flame structure. The temperature/residence time history that the particles experience in the flame nder different electrical fields and pressures has been estimated.