PREPARATION OF VAPOR-GROWN CARBON-FIBERS BY FLOATING CATALYST METHOD IN LINZ-DONAWITZ CONVERTER GAS - INFLUENCE OF CATALYST SIZE

Vapor-grown carbon fibers (VGCFs) were prepared using floating catalysts in Linz-Donawitz converter gas (LDG) under several conditions for supplying a benzene solution containing catalyst precursors. The size of the catalyst particles remaining inside the resulting fibers was determined. The yield of VGCFs depended on the experimental conditions (i.e., the temperature history of the catalyst particles before precipiting carbon on the catalyst, which was supposed to be a liquid phase). On the other hand, the size distribution of the catalyst particles showed no dependence on experimental conditions. The average catalyst size determined was 20 nm, which was thought to be appropriate for preparing VGCFs in LDG. The average particle size for each experimental run was evaluated using the catalyst growth model based on Brownian collision-coalescence motion. The model was found to be useful for determining the conditions for supplying the catalyst precursors dissolved in a benzene solution to obtain the approprite catalyst size.