Enhanced Formation of the Carbon Microcoils by the Stepwise Type Manipulation of CS2 Flow Injection

Abstract

Carbon coils were synthesized using C2H2 as source gas and CS2 as an incorporated additive gas under the thermal chemical vapor deposition system. The flow rate of CS2 varied according to the different reaction processes. Geometries of as-grown carbon nanomaterials were developed from vine-type into coil-type with increasing CS2 flow rate from 5 to 20sccm. Above 20sccm of CS2 flow rate, indeed, most of them were appeared as the tiny-sized wavelike nanocoil type geometries. To develop the double helix-type microcoils, namely the carbon microcoils, the injection of CS2 flow was manipulated as the stepwise type on/off-cycle manner. Under the specific condition of the on/off-cycle number, the density of the carbon microcoils was enhanced. The cause for the enhanced formation density of the carbon microcoils by the stepwise type manipulation of CS2 flow injection was suggested and discussed.