Formation of filamentous carbon from paraformaldehyde under high temperatures and pressures

Abstract

Synthesis of filamentous carbon from paraformaldehyde by high-temperature, high-pressure treatment under "hydrothermal" conditions is reported. Deposition of carbon started at about 600°C. Carbon filaments were grown at 650-750°C. Raman and X-ray diffraction studies demonstrated the amorphous structure and sp2 bonding of carbon in the filaments. Their length and thickness depended upon the experimental conditions. Well-ordered graphite was found at 800°C. Thermodynamic calculations of the decomposition of formaldehyde under high temperatures and high pressures were also carried out. The results of the thermodynamic and experimental study are compared. © 1998 Elsevier Science Ltd. All rights reserved.