PREPARATION OF COILED CARBON-FIBERS BY PYROLYSIS OF ACETYLENE USING A NI CATALYST AND SULFUR OR PHOSPHORUS COMPOUND IMPURITY

Coiled carbon fibers were prepared by pyrolysis of acetylene activated using a Ni catalyst and a small amount of impurities at 600-800-degrees-C. It was found that the addition of a small amount of sulfur or phosphorus compound impurities in acetylene was indispensable for the growth of coiled carbon fibers. Among the sulfur compounds used, thiophene was the most effective for growing coiled carbon fibers with uniform coil diameter and producing a high yield (about 50% coils). Similar results were obtained with phosphorus trichloride.