Synthesis of Pyrolytic Carbon Composites Using Ethanol As Precursor

Chemical vapor infiltration and deposition of carbon fiber bundles are applied to synthesize pyrolytic carbon composites using the oxygen-containing precursor ethanol. The influence of the temperature (1373 and 1423 K) and pressure (1−7 Pa) on the microstructure and the deposition rate of pyrolytic carbon are experimentally studied. Higher partial pressures of ethanol are demonstrated to favor the growth of highly ordered graphene-like pyrocarbon, whereas lower partial pressures help to suppress the carbon texture transition. The gas-phase composition and reaction kinetics are numerically analyzed on the basis of a reacting flow model with a detailed reaction mechanism. Methane and C2 species are shown to be the dominant intermediate species of ethanol pyrolysis. According to the simulation, a large amount of CH3 radicals is produced, which explains the fact that the pyrolytic carbon from ethanol exhibits a texture similar to the one produced with CH4 as precursor.