Growth of tubular carbon from vapor phase

The microstructure of tubular carbon varies radically such that variation in the diameter often leads to tubes with different physical properties. The control of diameter can therefore be a part of microstructure engineering. Such a control resides on the understanding of growth kinetics and mechanism. In this paper, the former was addressed. Investigation of the thickening behavior of chemical vapor deposited tubular carbons, with diameters ranging from ∼20 to 175 nm, is presented. The dependence of growth rate on the hydrocarbon concentration was found to be controlled not only by the temperature but also by the total gas flow rate. Also, previously reported beaded tubular carbon was found at lower temperatures than expected.