초록 ▼

A method of preparing carbon filaments which comprises exposing a suitable thermostable substrate which is covered with reduced monocrystalline metal particles with a diameter of at least 5 nanometers to a carbon containing gas mixture at temperatures of about 250°up to about 700°C., for a period of

A method of preparing carbon filaments which comprises exposing a suitable thermostable substrate which is covered with reduced monocrystalline metal particles with a diameter of at least 5 nanometers to a carbon containing gas mixture at temperatures of about 250°up to about 700°C., for a period of time sufficient to form filaments of the desired length, and thereafter removing the substrate and/or the metal particles. The filaments are characterized by a crystalline graphitic structure and a morphology defined by a fishbone-like arrangement of the graphite layers along the axis of the filaments. A high carbide content is a prerequisite for the nucleation of the filamentous carbon with a fishbone like structure.

대표청구항 ▼

A method for the preparation of carbon filaments, comprising the steps of exposing a thermostable support having substantially completely reduced monocrystalline ferro-magnetic metal particles to a carbon containing gas at a temperature of from about 250°C. up to about 700°C. to 800°C. for a period

A method for the preparation of carbon filaments, comprising the steps of exposing a thermostable support having substantially completely reduced monocrystalline ferro-magnetic metal particles to a carbon containing gas at a temperature of from about 250°C. up to about 700°C. to 800°C. for a period of time sufficient to promote epitaxial growth of graphite layers at the interface of the metal particle and the support, substantially each of said metal particle having a particle size of at least about 5 nanometers, forming carbon filaments on the support, the upper temperature limit of from 700°C. to 800°C. being contingent upon the stability of a metal carbide which is formed preceding the nucleation of filamentous carbon, said filaments being characterized by a crystalline graphitic structure and a morphology defined by a fishbone-like arrangement of the graphite layers along an axis of the filaments, adjusting loading of the support surface with the metal particles prior to the step of exposing the support and metal particles to the carbon containing gas to control the desired number of the carbon filaments per unit area of support surface, and thereafter separating the carbon filaments from the support.