Multi-centimeter length vapor grown carbon fibers for industrial applications

Vapor grown carbon fiber (VGCF) has been grown since long using the method of chemical vapor deposition. VGCF of tens of centimeter length were produced here using a thermal chemical vapor deposition system. A 6″ electric furnace and a 40 cm long ceramic substrate were used for the purpose. VGCFs were found to grow over 30 cm along the length of the substrate. The ceramic substrate was seeded with iron catalyst and kept almost at the center of the horizontal furnace during the VGCF growth. Before starting the furnace, evacuation of the tube was done with the help of a rotary pump and Ar was used to displace air from the tube. For the growth of VGCFs, mixtures of methane and hydrogen gases were used for a period of 1 to 2 h at 1100 °C. Effect of pre-heating was carried out to study the growth enhancement of VGCFs. Three pre-set temperatures were used for this purpose and preliminary results indicate that 300 °C and 400 °C of pre-heating increased the average diameter of fibers as well as the weight per unit area.