Carbon nanotubes (CNTs) are rolled-up sheets of graphene with diameters of around a nanometre to tens of nanometres and lengths up to many micrometres. They are sold in several types, and the choice between single-walled and multi-walled nanotubes affects cost, performance and how easy the material is to process. This guide summarises the differences to help you order the right grade.
The main types of carbon nanotubes
Single-walled carbon nanotubes (SWCNTs)
An SWCNT is a single graphene layer rolled into a seamless cylinder, typically about 0.8–2 nm in diameter. Depending on how the sheet is rolled (its chirality), an individual SWCNT can be metallic or semiconducting. SWCNTs have very high surface area and excellent electrical and optical properties, which makes them the choice for transparent conductive films, field-effect transistors, sensors and many research applications.
Double-walled carbon nanotubes (DWCNTs)
DWCNTs have two concentric walls. They keep much of the conductivity of SWCNTs while the outer wall can be functionalised without disturbing the inner one, which is useful for composites and conductive coatings.
Multi-walled carbon nanotubes (MWCNTs)
MWCNTs consist of several to dozens of nested tubes, with outer diameters typically from about 5 to 50 nm or more. They are produced at much larger scale and cost far less per gram, which is why they dominate industrial uses such as conductive additives in lithium-ion battery electrodes, antistatic plastics, conductive rubbers and reinforced composites.
SWCNT vs MWCNT at a glance
| Property | SWCNT | MWCNT |
|---|---|---|
| Structure | One graphene wall | Several nested walls |
| Typical diameter | ~0.8–2 nm | ~5–50 nm and above |
| Electrical behaviour | Metallic or semiconducting, depending on chirality | Generally metallic-like conduction |
| Specific surface area | Very high | Lower |
| Relative cost | Higher | Lower, available in bulk |
| Typical uses | Transparent films, electronics, sensors, research | Battery additives, composites, coatings, antistatic plastics |
Specifications to check before you order
- Purity (carbon content) – residual catalyst metals and amorphous carbon affect conductivity and can interfere with electrochemical or biological work.
- Outer diameter and length – longer tubes help percolation in composites; shorter tubes disperse more easily.
- Functionalisation – –COOH, –OH or –NH2 functionalised CNTs disperse better in water and polar polymers and bond better to matrices.
- Form – dry powder, aqueous or solvent dispersion, paste or film. Dispersions save you the effort of sonication and surfactant selection.
- Characterisation – Raman (G/D ratio), TEM and TGA data on the certificate of analysis help confirm quality.
Which one should you choose?
- Choose SWCNTs for transparent conductive films, nanoelectronics, sensors, optical studies and research where single-tube properties matter.
- Choose MWCNTs for battery electrode additives, conductive plastics and coatings, mechanical reinforcement and any application needing kilogram quantities at a reasonable cost.
- Choose functionalised CNTs or a ready dispersion if you struggle to disperse the dry powder.
Handling and safety
CNT powders are very light and easily become airborne. Handle them in a fume hood or ventilated enclosure, wear gloves, safety glasses and a suitable respirator, and avoid creating dust. Store containers tightly closed in a dry place. Refer to the safety data sheet supplied with the product.
Buying carbon nanotubes in India
Aritech Chemazone supplies single-walled, double-walled, multi-walled and functionalised carbon nanotubes manufactured by Nanochemazone Canada, as powders and dispersions. Browse the carbon nanotubes range, including multi-walled carbon nanotube powder and carboxyl-functionalised MWCNTs, or the wider Carbon & 2D Materials category, and use Get Quotation on any product page for an INR price with GST and delivery anywhere in India.
Frequently asked questions
Are single-walled carbon nanotubes better than multi-walled?
Neither is better in general. SWCNTs offer higher surface area and tunable electronic properties; MWCNTs are cheaper, available in bulk and ideal for conductive additives and composites.
Why are SWCNTs more expensive?
They are harder to grow selectively and to purify, and they are produced in smaller volumes than MWCNTs.
Can I get carbon nanotubes as a dispersion?
Yes. Aqueous and solvent dispersions of CNTs are available, and custom concentrations can be arranged on request.
Which CNTs are used in lithium-ion batteries?
Multi-walled carbon nanotubes, often supplied as a conductive paste or dispersion, are widely used as conductive additives in battery electrodes.
Do you provide a certificate of analysis?
Yes, every order comes with a certificate of analysis from the manufacturer.