Ultralong single-wall carbon nanotubes

Abstract

Since the discovery of carbon nanotubes in 1991 by Iijima, there has been great interest in creating long, continuous nanotubes for applications where their properties coupled with extended lengths will enable new technology developments. For example, ultralong nanotubes can be spun into fibres that are more than an order of magnitude stronger than any current structural material, allowing revolutionary advances in lightweight, high-strength applications. Long metallic nanotubes will enable new types of micro-electromechanical systems such as micro-electric motors, and can also act as a nanoconducting cable for wiring micro-electronic devices. Here we report the synthesis of 4-cm-long individual single-wall carbon nanotubes (SWNTs) at a high growth rate of 11 microm s(-1) by catalytic chemical vapour deposition. Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.

Photophysics of Individual Single-Walled Carbon Nanotubes

“…The carbon source is typically a gas or volatile compound such as methane, 16,17 ethanol, 18,19 carbon monoxide, 20 or a combination of these. Methane is the most commonly used hydrocarbon due to its kinetic stability at high temperatures and limited production of amorphous carbon.…”

“…34 Two categories of VLS that are relevant to nanotube synthesis are tip growth and base growth (Figure 1-4). 31 Specifically, if the catalyst particle is weakly attached to the substrate, it will ride along the developing tip of the SWNT during synthesis (tip growth); 19,35,36 on the other hand, growth will proceed from the SWNT base if the catalyst is strongly associated with the substrate (base growth). 37,38 Atomic force microscopy (AFM) or TEM can elucidate whether the catalyst particle is situated at the tip or base of the SWNT during synthesis (Figure 1-4).…”

“…in 2002, 71 ultrasonic processing has been used to isolate SWNTs in an extensive library of dispersing agents including surfactants, 119,130 polymers, 120 single-stranded DNA, 19,132,133 peptides, 134 and cagelike molecules such as Sarkosyl. 135 Figure 3-1 contrasts the appearance of an aqueous suspension containing mostly bundles and an aqueous sample enriched in isolated SWNTs.…”

Nanobarrier-terminated growth of single-walled carbon nanotubes on quartz surfaces

“…Based on the VLS mechanism, many methods have been developed to grow SWNTs in a controlled manner. For example, the size distribution of catalyst nanoparticles can strongly influence the distribution of nanotube diameters [3,4]; special catalysts can grow SWNTs with narrow chirality distributions [5,6]; site-controlled catalyst nanoparticles determine the growth position of carbon nanotubes [7]; the carbon feeding rate during the growth can be used to control the diameter distribution of SWNTs [8]; the growth of SWNTs Nano Res (2009) 2: 768 773 Áoating in the gas phase [9,10] can afford ultra-long Á carbon nanotubes (up to centimeters in length); and on single-crystal substrates, such as sapphire [11,12] and quartz [13,14], SWNTs with extremely high alignment can be grown. However, for an individual carbon nanotube, it is difÀ cult to control its growth, À because the active growth time and growth rate depend on the activity of the catalyst, which is uncontrollable.…”

Resonance R aman Spectroscopy

“…For the horizontal direction growth, its success has been reported by many groups by using an electric field [43][44][45], a fast gas flow [46,47], and atomic steps of substrates [25,26,48,49,50,51] with other carbon sources. Furthermore, the ACCVD method has not been used for only random or VA-SWNTs, but also for horizontally-aligned SWNTs [52].…”