High-temperature pyrolysis and oxidation of fullerene C{sub 60} behind shock waves
- Univ. Duisburg (Germany). Inst. fuer Verbrennung und Gasdynamik
Submicron fullerene C{sub 60} particles dispersed in a carrier gas and shock-heated to temperatures of about 2,000 K evaporate in a few microseconds to form C{sub 60} vapor. In a first group of experiments, the high-temperature pyrolysis of C{sub 60}/Ar mixtures behind reflected shock waves was studied at temperatures 2370 K {<=} T {<=} 3500 K. Spectral and time-resolved emission in the wavelengths range 280 nm {<=} {lambda} {<=} 580 nm was detected by an intensified charge coupled device (CCD) camera. From the time-dependent emission at specified wavelengths, the decomposition rate of C{sub 60} was determined, which seems to obey an Arrhenius law. At temperatures above 2,600 K, spectral band structures appear, which could be identified to result from C, emission. In the second group of experiments, the high-temperature oxidation of fullerene in C{sub 60}/O{sub 2}/Ar mixtures was studied at temperatures 1,655 K {<=} T {<=} 2,705 K and pressures between 1.5 and 2.6 bar. The progress in the oxidation was measured by tunable IR-diode laser absorption of CO and CO{sub 2}. Additionally, the spectral and time-resolved emission during the fullerene oxidation was recorded by the CCD camera. From the time-dependent increase of CO concentration and the time-dependent decrease of the spectral emission, apparent rate, coefficients for the formation of CO and the disappearance of C{sub 60} were determined.
- OSTI ID:
- 93215
- Report Number(s):
- CONF-940711--
- Country of Publication:
- United States
- Language:
- English
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