Formation of condensed particles from supersaturatedcarbon vapor behind shock waves

摘要

The process of condensed carbon particle formation during pyrolysis of hydrogen freerncarbon bearing molecules C3 O2 , CCl4 and C2 Cl4 behind shock waves in the wide temperaturernrange 1200 - 3800 K was investigated. The comparison of extinction properties of young, growingrnparticles with the electron microscopic analysis of solidified substance gave a notion about thernpeculiarities of the carbon particle formation process from the different carbon bearing gasesrnat various temperatures. Particles, forming at 1500-2000 K, look similar to usual soot. At therntemperatures 2100-2600 K the decrease of the particle formation rate and the fall of final particlernyield in all mixtures is observed, followed by the gigantic film-like spheres with the size up torn700 nm deposited on the walls. The peculiarity of the high temperature (2700-3200 K) processrnof carbon particle formation is the high degree of crystallization of the final particles.