Single Walled Carbon Nanotubes are hollow, cylindrically shaped allotropes of carbon that have a high aspect ratio (length to diameter ratio). Their name is derived from their structure and the walls are formed by multiple one-atom-thick sheets of carbon. SWNTs consist of a single rolled layer of carbon atoms held together in a tube structure by Van der Waals forces. Depending on the chiral angle of how the tube is formed, they are considered semiconducting or metallic in nature. They’re inert and can be used to increase mechanical and conductive properties in other materials.
We supply a wide variety of high quality single walled-double walled carbon nanotubes (SW/DWNTs) with a variety of purities and functionalities.
Prices are per gram for powder form and dispersions are available, please contact us for details.
Quotes are available online thru our cart. Simply add the products and quantities you need into the cart and then you can print or download a quote.
To learn the price for a specific product and quantity, please click thru to the individual product page and enter the quantity you need. Our website will display the price for that specific quantity.
We provide aqueous, solvent, & polymer dispersions-emulsions with traditional surfactants or our patented surfactant free method.
Please Note- SWNTs can’t be produced homogeneously by CCVD, they always contain significant DWNTs content. For this reason we call all of our former SWNT products a SW-DWNT mix.
Single Walled Double Walled Carbon Nanotube Definition
The Single Walled Carbon Nanotubes (SWCNTs) definition is a carbon nanotube consisting of a single tube of carbon atoms arranged in a hexagonal pattern with isolated 5 and 6 member rings. There are different types of single walled carbon nanotubes because the graphitic sheets can be grown with different chiral angles during synthesis.
SWCNTs are an important variety of carbon nanotube because most of their properties change significantly with differing (n,m) values. In particular, their band gap can vary from zero to about 2 eV and their electrical conductivity can show metallic or semiconducting behavior.
True single walled carbon nanotubes are 0.7-1.2nm outer diameter and can be anywhere from 0.5-30um long. Longer SWCNTs are available in array form, up to 500um.
How to recognize the atomic structure of Single Walled Carbon Nanotubes
The three types of Carbon Nanotubes (CNTs) structure are Zigzag, Armchair, and Chiral. It’s possible to recognize zigzag, armchair, and chiral Carbon Nanotubes (CNTs) just by following the pattern across the diameter of the tubes, and analyzing their cross-sectional structure.
Single Walled Carbon Nanotubes Properties
Desirable single walled carbon nanotubes properties include high strength as well as high electrical and thermal conductivity.
They are very resilient. When CNTs are bent, they buckle but do not break. In fact, they can easily be straightened out without any damage to the physical structure. Their Young’s modulus ranges from 1.28 – 1.8 TPa (tera pascals). One tera pascal is a pressure of about seven orders of magnitude greater than atmospheric pressure. The Young’s modulus of steel is 0.21 TPa, which means the Young’s moduli of CNTs are typically ten times greater than that of steel.
The electrical conductivity of Single Walled Carbon Nanotubes is determined by their chiral structure, diameter, and length. A diameter in the nanometer range gives rise to quantum effects and they can either be conducting or semiconducting, depending on their chirality. SWCNTs are
metallic if the integers of equation (1) are: n=m (the armchair structure) and n-m=3i (where i is an
integer). All other structures are semiconducting. Their geometry determines the band structures and the energy band gap.
Single walled carbon nanotubes thermal conductivity is about 3400 W/m K near 300 K
What’s the difference between single walled and multi walled carbon nanotubes?
A single walled carbon nanotube has just one wall. True SWCNTs are typically made by HIPCO or Arc methods. A multi walled carbon nanotubes are tubes inside of other tubes as shown in the image below. MWCNTs can have different chiral structures within the same CNT.
Single Walled Carbon Nanotube Applications
Single walled carbon nanotubes applications include advanced electrodes, conductive films and coatings (including transparent conductive coatings), solar, and sensor applications.
Single-walled nanotubes have been applied as the most basic building block of these systems is the electric wire, and SWNTs with diameters of an order of a nanometer can be excellent conductors. A useful application of SWNTs is in the development of the first intermolecular field-effect transistors (FET). The first intermolecular logic gate using SWCNT FETs was made in 2001. A logic gate requires both a p-FET and an n-FET. Because SWNTs are p-FETs when exposed to oxygen and n-FETs otherwise, it is possible to expose half of an SWNT to oxygen and protect the other half from it. The resulting SWNT acts as a not logic gate with both p and n-type FETs in the same molecule.
Publications using Single Walled Carbon Nanotubes from Cheap Tubes Inc