Aligning carbon nanotubes, synthesized using the arc discharge technique, during and after synthesis

Alignment of multi-walled carbon nanotubes (MWCNTs) is demonstrated using physical forces both during synthesis, as well as post-synthesis through the arc discharge technique. The arc discharge process results in relatively straight and defect free MWCNTs compared to other techniques such as chemical vapor deposition. A scraper enables alignment of these straight MWCNTs during synthesis. Additional tailoring of the direction of alignment is seen to be possible even at room temperature, using physical forces in the form of scratch marks on the soot. Using a hand operated roller, on the surface of the soot, also results in the alignment of MWCNTs along the rolling direction. Alignment of MWCNTs is confirmed using scanning electron microscopy and it results in distinct changes in X-ray diffraction and energy dispersive spectroscopy data. These results are significant from the perspective of obtaining aligned MWCNTs, in large quantities, in a relatively inexpensive manner. (C) 2012 Elsevier Ltd. All rights reserved.