Flame combustion synthesis chemical reactions

An important topic of research is the introduction of the catalyst in the microreactor. In brief solid catalysts can be incorporated on the interior of micromachined reaction channels, prior to or after closure of the channel, by a variety of strategies anodic oxidation, plasma-chemical oxidation, flame combustion synthesis, sol-gel techniques, impregnation, wash coating, (electro-)plating, aerosols, brushing, chemical vapor deposition, physical vapor deposition and nanoparticle deposition or self-assembly. Some of these methods can be applied in combination with photolithography or shadow masking. 

In combustion synthesis in gas systems (gas- rgas), the reactions occur in counterflow or co-flow diffusion flames (SiH4+NH3 Si3N4 (d), Si(CH3)+C2H4+02 - SiC (7), TiCl4+N2+Na->TiN (8), etc.). Here, the process is controlled by the diffusion in gases. If the characteristic time of diffusion, td, is lower than the characteristic time of chemical reaction, tr, then a process occurs in the kinetic mode. The conversion (rj) for gas- gas systems may be as great as 100%. 

Chemical Vapor Deposition (CVD) has been defined as a materials synthesis process whereby constituents of the vapor phase react chemically near or on a substrate surface to form a solid product. With these traditional processes a reaction chamber and secondary energy (heat) source are mandatory making them different from the Combustion CVD process. Numerous flame-based variations of CVD have been used to generate powders, perform spray pyrolysis, create glass forms, and form carbon films including diamond films. 

In this paper we present a new technique for the synthesis of carbon film with carbynoid structures. The basis of the method described here consists of a combustion reaction between oxygen and acetylene and particular parameters for flame conditions. The flame volume can be considered as the reaction chamber as in conventional chemical vapor deposition (CvD) or physical vapor deposition (PVD) methods. This technique provides a method of synthesizing carbyne at high growth rates and of obtaining better crystals. 

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