Preparation of Coiled Carbon Fibers by CVD

Abstract

Coiled carbon fibers were prepared by catalytic pyrolysis of acetylene at 500-800°C using Ni powder as a catalyst. It was found that the presence of small amounts of impurity gas, such as H2S, PCl3, was indispensable for the growth of coiled carbon fibers with good yield and reproducibility. Maximum yield (about 80%) of the coiled carbon fibers were obtained using PCl3 as an impurity. Optimum flow rate of PCl3 was 0.05-0.1 ml/min, and coiled carbon fibers were not obtained at a flow rate of zero or above 0.15 ml/min. Morphology and growth mechanism of the coiled carbon fibers were discussed. The mechanical property of the coiled carbon fibers were examined.