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

A new approach for gas-phase combustion synthesis of nanosized particles using a novel hybrid burner facility is demonstrated. The basis of the synthesis technique is to use both a premixed flame and a diffusion flame to control the synthesis environment. Specific experimental results for silica (SiO₂) production from silane/hydrogen/oxygen/argon (SiH₄/H₂/O₂/Ar) flames are presented. A parametric study of several burner conditions was conducted, and the subsequent effects on the particles produced were determined. Particle 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 (in particular, reactant stoichiometry and flame geometry). Particle structures were aggregated with primary particles varying from 6–8 nm in size (high oxygen concentration conditions) to larger more continuous structures with primary particles 18–20 nm in size (low oxygen concentration conditions). Bulk material properties were examined using Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), nitrogen adsorption (BET) and x-ray diffraction (XRD).