Synthesis of Ultrafine Particles by Reactions in Electrical Discharges and its Application

Abstract

Corona and silent mode electrical discharges were applied as a means of activation in a CVD reaction. The discharge was formed stably by a high voltage and high frequency a. c. -power supply in an ozonizer-type reactor in an Ar gas atmosphere. Ultrafine SiO₂ particles were synthesized by the hydrolysis reaction of silicone tetrachloride in discharges at room temperature and atmospheric pressure. The basic properties of the CVD reaction excited by electrical discharges were experimentally studied.
The proposed CVD reaction method was applied to ceramic membrane formation and to the hydrolysis reaction of silicon alkoxide. A ceramic membrane which has a fine pore of about 0.5μm and a large porosity was formed by sintering the deposited particle layer. SiO₂ particles which have alkoxylated surfaces were synthesized directly from silicon tetraethoxide.