II International Symposium on Carbon for Catalysis ABSTRACTS

PP-I-32
It was detected, that precursor concentration in carbon nanofibers depends on carbon
formation rate and synthesis time. Concentration decreases when carbon formation rate or
synthesis time increases.
Influence of synthesis temperature, gas flow and gas composition on nanofibers diameter.
• Temperature rise leads to diameter decreasing.
• Nanofiber diameter decreases with decreasing of carbon monoxide concentration in
gas mixture.
• Increasing of gas flow leads to diameter increasing.
It is detected, that synthesis temperature increasing and carbon formation rate decreasing
leads to formation of more graphitic nanofibers.
The carbon composites synthesis investigations show:
1. Two processes compete at the beginning of carbon matrix formation, when using
carbon nanofibers containing precursor metal. Fist – carbon nanofibers growth continues;
second - pyrocarbon formation. Then – only pyrocarbon precipitates and forms matrix. If used
nanofibers do not include precursor – only pyrocarbon precipitation is observed.
2. Cavity formation and diameter reduction is originated during nanofibers oxidation.
Only cavities are formed, when we oxygenate nanofibers pyrocarbon covered. Oxidation rate
increases in metal precursor presence.
3. The increasing of process temperature leads to pyrocarbon formation and oxidation
rates increasing.
Sorption characteristics of carbon nanofibers and materials based on them have been
discussed.
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