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Home 5 Frequently Asked Questions

Frequently Asked Questions


Our Products

What is the diameter and length of your nanotubes?

Individual tube lengths range from 0.5-3µm and have an average diameter of 1.4 nm. SWNT tend to occur as bundles with bundle lengths of 1-5µm and average bundle diameters of 2-10nm. 

Type of material Bundle Length Bundle Diameter
AP-SWNT 1-5µm 2-10nm
P2-SWNT 500nm-1.5µm (~1.0µm) 4-5nm
P3-SWNT 500nm-1.5µm (~1.0µm) 4-5nm
P5-SWNT 500nm-1µm 2-8nm
P7-SWNT 500-600nm 4-5nm
P8-SWNT 500-600nm 4-5nm
Are your nanotubes open-ended or close-ended?

Our AP-SWNT are close-ended, but all of our purified and functionalized SWNTs have open ends as a result of the processing of nanotubes.

What is the difference between P2-SWNT and P3-SWNT?

Both of these types of nanotubes are purified. The difference is in the way they are purified. P2- and P3-SWNTs are materials of the same quality, but with different characteristics: P2-processing produces high purity material with almost no functionalities, while P3-material has the same carbonaceous and metal content purity, but it is more compatible with further chemical processing. A specific feature of P3-SWNT is the presence of carboxylic acid groups, which makes this material dispersible in water and other solvents and more compatible with further chemical processing including composite applications. Typically, P3-SWNT have 3-6 % carboxylic acid groups. This material is p-doped, which can be observed in optical transitions. Annealing at 400oC in vacuum leads to de-doping of the material. We intentionally do not include annealing in P3-processing in order to conserve the high degree of carboxylic functionalities, important for specific applications. 

P2-SWNTs material is obtained by different purification root, which involves air oxidation and subsequent treatment in acid to remove the catalyst. As a result, the P2-processing produces high purity material with the most intrinsic behavior (the treatment does not dope the SWNTs). It does not have attached acidic functionalities and it is less dispersable in water and other solvents.

Where on the nanotubes are the functional groups found?

The functional groups are introduced both at the ends and along the side walls of the tubes.

What is the density of your AP-SWNT?

1.2 to 1.5 g/cm3

What types of nanotubes does CSI produce?

We synthesize our single-walled carbon nanotubes (SWNTs) using the electric arc discharge method and refer to this product as AP-SWNT (as-prepared). The ratio of semiconducting to metallic SWNTs produced through this method is 2 to 1. The nanotubes are produced using nickel/yttrium catalyst. We also have a wide variety of purified and functionalized SWNTs, which are offered for sale (for further information refer to the product description sheet and product specification sheets).

What are good solvents for Arc-Produced SWNTs?

DMF (Dimethyl formamide) is the most common solvent to disperse arc-produced SWNTs. Dispersing SWNTs requires sonication. SWNTs can also be dispersed in water using surfactants such as SDS (Sodium Dodecyl Sulfate), also using sonication. Other solvents such as ethanol can be used, however the dispersions are not very stable and tend to fall out of solution very quickly. The stability of the dispersion depends on the concentration (see the specification sheets for details).

My Orders

How can I place and order?

The easiest way to place an order is by filling out the Online Order Form. The customer must provide us with a purchase order # on the form. Purchase Orders can also be faxed to 1-951-682-5627.

Do you accept credit cards?

At this time we are not set up to accept credit card statements. We handle all of our ordering through purchase orders.


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