US EPA

8332625 

Journal Article 

Grow carbon fibers in the vapor phase 

Endo, M 

1988 

Yes 

CHEMTECH
ISSN: 0009-2703 

AMER CHEMICAL SOC 

WASHINGTON 

18 

9 

568-576 

English 

WOS:A1988Q177200013 

The history of carbon fibers is briefly sketched along with the historic models proposed for growth: spiral growth and the impurity model. The forming of vapor-phase-grown carbon fiber is described as comprising two steps: the fiber first forms over fine catalyst particles of iron or other relevant metals dispersed over the substrate; it then grows in the radial direction, resulting in fibers several decimeters long and about 10 μm in diameter. Temperature and timing are controlled throughout the process. The VGCF production process consists of three steps: (1) seeding, in which ultrafine metallic catalyst particles serving as nuclei for the fiber growth are dispersed over the substrate surface; (2) growth of fine precursor fiber; and (3) deposition of the thermally decomposed hydrocarbons over the precursor fiber to increase its radial size. The dispersion of the fine catalyst particles, such as those of iron, is the key process for the mass production of VGCF. The seeding step largely determines the density of the growing fiber, i.e., the number of fibers per unit area of the substrate, and hence the productivity. A brief discussion covers the growth model and mechanism.