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 catalys ts in Linz-Donawitz converter gas (LDG) under several conditions for s upplying a benzene solution containing catalyst precursors. The size o f the catalyst particles remaining inside the resulting fibers was det ermined. The yield of VGCFs depended on the experimental conditions (i .e., the temperature history of the catalyst particles before precipit ing carbon on the catalyst, which was supposed to be a liquid phase). On the other hand, the size distribution of the catalyst particles sho wed no dependence on experimental conditions. The average catalyst siz e determined was 20 nm, which was thought to be appropriate for prepar ing VGCFs in LDG. The average particle size for each experimental run was evaluated using the catalyst growth model based on Brownian collis ion-coalescence motion. The model was found to be useful for determini ng the conditions for supplying the catalyst precursors dissolved in a benzene solution to obtain the approprite catalyst size.