A Brief Overview on Flame Spray Synthesis

Abstract

The technology involving the flame spraying of a precursor solution is based on the formation of small particles from the gas or vapor phase in a flame. Flame spray (FS) is regarded as a consolidated industrial technique, as discussed in the previous chapter. However, the principles and fundamentals of the particles synthesis in the flame are not completely understood. One of the main reasons for the absence of a complete description of FS synthesis is the fact that chemical reactions and particle formation occurs in a short time and high temperature during the process. The basic principle of FS technique is the formation of vapor or aerosol of the precursor compounds, which reacts in the high temperature of the flame leading to the formation of a ceramic compound. There are two basic types of process based on the formation of an aerosol and further spraying in a flame. The former is the conversion to a particle from the vapor phase, due to the presence of a flame, and named vapor synthesis in a flame. The second process comprises the conversion of a droplet to a particle, also assisted by a flame, and named FS pyrolysis.