Carbon Nanotubes: Vertically Aligned Single-Walled Carbon Nanotubes by Chemical Assembly - Methodology, Properties, and Applications (Adv. Mater. 13/2010)

Diameter modulation of vertically aligned single-walled carbon nanotubes.

We demonstrate wide-range diameter modulation of vertically aligned single-walled carbon nanotubes (SWNTs) using a wet chemistry prepared catalyst. In order to ensure compatibility to electronic applications, the current minimum mean diameter of 2 nm for vertically aligned SWNTs is challenged. The mean diameter is decreased to about 1.4 nm by reducing Co catalyst concentrations to 1/100 or by i...

A Growth Mechanism for Vertically Aligned Single-Walled Carbon Nanotubes

One of the difficulties in developing practical nanotube-based devices is the large-scale production of aligned carbon nanotubes (CNTs). Due to their novel electronic and thermal properties, single-walled nanotubes (SWNTs) show great potential for use a variety of applications . The alignment of SWNTs has been reported, but only parallel to the substrate in the presence of strong electric or ma...

Polarized Raman spectroscopy on vertically aligned single-walled carbon nanotubes

Vertically aligned single-walled carbon nanotube (VA-SWNT) films with high purity have been prepared up to 30 μm thick by the alcohol catalytic chemical vapor deposition (CVD) method[1][2]. In a previous polarized Raman spectroscopy study, we found anomalous anisotropic peaks such as at 180 cm for the excitation by 488 nm laser and explained them as perpendicularly polarized excitation [3]. How...

Growth Process of Vertically Aligned Single-walled Carbon Nanotubes

The growth process of vertically aligned single-walled carbon nanotube (SWNT) films was investigated by means of in situ optical analysis and scanning electron microscopy. The measurements reveal that the growth of the SWNT film decreases after longer reaction times. This decrease is attributed to a combination of a diminishing growth rate and burning of the SWNTs due to oxygen in the growth ch...

Carbon Nanotubes from Unconventional Resources: Part A: Entangled Multi-Walled Carbon Nanotubes and Part B: Vertically-Aligned Carbon Nanotubes