Single-Walled Carbon Nanotubes

What Are Single-Walled Carbon Nanotubes (SWCNTs)?

Single-walled carbon nanotubes are seamless cylinders formed by rolling a one-atom-thick graphene sheet into a tube, typically 0.4 to 2 nm in diameter and up to many micrometers long. Their electronic behavior comes directly from graphene: depending on how the lattice is rolled, described by the chiral vector, an SWCNT can be metallic or semiconducting. This makes them one of the most studied nanomaterials for both applied and fundamental research. For a broader introduction, see our guide on single-walled carbon nanotubes explained, part of our overview of carbon nanotube fundamentals and industrial applications.

Electrical, Mechanical, and Thermal Properties

SWCNTs combine several extreme properties in one material. Individual tubes carry current densities on the order of 10⁹ A/cm², well above copper or gold, and semiconducting SWCNTs show electron mobility higher than silicon. Their conductivity can be metallic or semiconducting with a tunable band gap set by lattice orientation, which is why they attract interest for both interconnects and transistors. Mechanically, SWCNTs have tensile strength many times that of steel at roughly one-sixth the weight, combining stiffness with high strain tolerance. Thermally, conductivity along the tube axis can substantially exceed that of copper, making SWCNTs effective in thermal interface materials.

Properties at a Glance

• Diameter typically 0.4 to 2 nm with high aspect ratio
• Metallic or semiconducting behavior depending on chirality
• Current-carrying capacity on the order of 10⁹ A/cm²
• Electron mobility exceeding silicon in semiconducting species
• Tensile strength many times higher than steel at a fraction of the weight
• High axial thermal conductivity for heat management

SWCNT vs MWCNT

The main structural difference is wall count. SWCNTs have a single wall, giving them a well-defined band gap and superior electronic and optical behavior, which suits transparent conductors, sensors, and transistors. Multi-walled carbon nanotubes have several concentric walls, offering higher structural robustness and lower cost, which favors bulk composite reinforcement. Our comparison of SWCNT vs MWCNT explains how to choose between them, and the alternatives include double-walled and multi-walled grades.

Applications

Their combination of electronic and mechanical properties makes SWCNTs useful across many fields, including field-emission displays, transparent conductive films, nanocomposites, nanosensors, and logic elements. Semiconducting SWCNTs are studied for thin-film transistors and flexible electronics, while metallic tubes serve conductive networks and interconnects. For processing into coatings and inks, SWCNTs are also available as carbon nanotube dispersions. The material is produced by several routes, summarized in our overview of the main carbon nanotube synthesis methods.

Research and Documentation

Materials supplied by Nanografi are used in peer-reviewed research across electronics, energy, and composites. You can review the publications citing Nanografi materials to see how SWCNTs and related nanomaterials have been characterized and applied. Every grade ships with documentation covering diameter, purity, and functionalization.

Frequently Asked Questions

Where can I buy single-walled carbon nanotubes?

You can buy single-walled carbon nanotubes directly from Nanografi. We supply SWCNTs with defined diameter, purity, and functionalization, for both research and industrial use, with worldwide shipping.

What is the difference between SWCNT and MWCNT?

SWCNTs have a single wall and a defined band gap, giving superior electronic and optical properties for sensors, transistors, and transparent conductors. MWCNTs have multiple concentric walls, offering greater robustness and lower cost for composite reinforcement.

Are single-walled carbon nanotubes metallic or semiconducting?

Both. Whether an SWCNT is metallic or semiconducting depends on its chirality, that is, how the graphene lattice is rolled into the tube. As-produced material is usually a mixture of both types.

What are single-walled carbon nanotubes used for?

Common applications include field-emission displays, transparent conductive films, thin-film transistors, nanosensors, logic elements, and nanocomposite reinforcement.

Buy Single-Walled Carbon Nanotubes at Nanografi

Nanografi supplies single-walled carbon nanotubes with documented diameter, purity, and functionalization, so you can specify the grade your application requires. SWCNTs sit within our broader carbon nanotubes range and our full catalog of advanced materials, with worldwide shipping and technical support. Browse the listings above to find the right SWCNT grade for your work.