Comparison of vertically aligned carbon nanotube array intercalated production among vermiculites in fixed and fluidized bed reactors

Vertically aligned carbon nanotube (CNT) arrays with ordered nanostructure and extraordinary performance have become an important advanced material. CNTs were synchronously grown with high density to form aligned morphology, while the fine agglomerated structure was sensitive to the packing style of catalyst particles. Thus, synthesis of CNT arrays in a fixed bed or fluidized bed is an important issue. We reported that CNT arrays were grown from ethylene on a lamellar catalyst in a fixed bed reactor and a fluidized bed reactor, respectively. The reactor style affected the intercalated growth of CNT arrays greatly. The qualities of CNT array products in the fixed bed showed a distribution along the axis direction. The CNT arrays obtained at the top of the fixed bed were of good alignment and small diameter; while for the products obtained at the bottom of the reactor, CNT array blocks with higher densities, larger diameter, shorter length, and more defects, were formed. When CNT arrays were grown in a fluidized bed, they were of homogeneous structure, low densities, small uniform diameter, and had little defects, which can be attributed to available space, uniform temperature and reactant distribution in the fluidized bed reactor. These favored the mass production of CNT arrays with uniform properties in a fluidized bed reactor. (C) 2009 Elsevier B.V. All rights reserved.