Demonstration of gas-phase combustion synthesis of nanosized particles using a hybrid burner

A new approach for gas-phase combustion synthesis of nanosized particles us ing a novel hybrid burner facility is demonstrated. The basis of the synthe sis technique is to use both a premixed flame and a diffusion flame to cont rol the synthesis environment. Specific experimental results for silica (Si O2) production from silane/hydrogen/ oxygen/argon (SiH4/H-2/O-2/Ar) flames are presented. A parametric study of several burner conditions was conducte d, and the subsequent effects on the particles produced were determined. Pa rticle morphology was examined using transmission electron microscopy (TEM) . The results indicated a broad variation in particle size and structure as a function of the burner operating conditions tin particular, reactant sto ichiometry and flame geometry). Particle structures were aggregated with pr imary particles varying from 6-8 nm in size thigh oxygen concentration cond itions) to larger more continuous structures with primary particles 18-20 n m in size (low oxygen concentration conditions). Bulk material properties w ere examined using Fourier transform infrared spectroscopy (FTIR); thermal gravimetric analysis (TGA), nitrogen adsorption (BET) and x-ray diffraction (XRD). (C) 1999 Acta Metallurgica Inc.