OXIDATION OF FULLERENE C-60 BEHIND SHOCK-WAVES - TUNABLE DIODE-LASER MEASUREMENTS OF CO AND CO2

Submicron fullerene C-60 particles dispersed in a carrier gas and shoc k heated to temperatures of about 1500 K evaporate in a few mu s to fo rm C-60 vapour. The high temperature oxidation of fullerene in O-2/Ar mixtures was studied at temperatures 1655 K less than or equal to T le ss than or equal to 2705 K and pressures between 1.5 and 2.6 bar. The progress in the oxidation was measured by tunable IR-diode laser absor ption of CO and CO2. A multipass cell incorporated into the shock tube was used to enhance the initial absorption path length. Additionally the spectral and time resolved emission during the fullerene oxidation was recorded by an intensified CCD camera. In a wavelength range 280 nm less than or equal to lambda less than or equal to 530 nm typical s pectra for C-60 and C-2 were detected. From the time dependent increas e of CO concentration and the time dependent decrease of the spectral emission apparent rate coefficients for the formation of CO and the di sappearance of C-60 were determined.