Frequently Asked Questions (FAQs)

  1. What are the contents of your aqueous solutions?
  2. What are the contents of your powders?
  3. What is the concentration of nanotubes in your aqueous solutions?
  4. What is the shelf life of your solutions? What is a BIUB Code?
  5. Can you offer your solutions in different concentrations?
  6. How do I remove the surfactants from your tubes?
  7. Do you sell functionalized CNTs?
  8. What is the length distribution of your nanotube products?
  9. Can you make your nanotubes shorter?
  10. Can you make your nanotubes longer?
  11. What is the diameter range of your nanotubes?
  12. Can you produce nanotubes with a narrower range (1.2 – 1.3 nm, for example)?
  13. What chiralities are present in your nanotubes?
  14. Can you sort nanotubes by chirality?
  15. Do you acid treat your nanotubes to purify them?
  16. Do your products contain residual catalyst impurities?
  17. Do your products contain a lot of carbonaceous junk?
  18. How do you quantify the metallic and semiconducting purity of your products?

What are the contents of your aqueous solutions?

Our PureTube and IsoNanotube solutions contain dionized water, nanotubes, and a proprietary combination of ionic surfactants. Our IsoNanotube solutions also contain some iodixanol, a water-soluble, non-ionic iodine derivative which we use as a density gradient medium.

What are the contents of your powders?

Our powders are comprised of nearly 100% nanotubes. We do not use any binders or fillers.

What is the concentration of nanotubes in your aqueous solutions?

PureTubes: 0.25 mg/mL
IsoNanotubes: 0.01 mg/mL

What is the shelf-life of your solutions? What is a BIUB Code?

There are four different types of solutions for our nanomaterials, which can be placed into two general groups: Aqueous and Aromatic. For both groups of solutions, the shelf-lives are ideally six months when stored at room temperature, without direct exposure to sunlight. For the aromatic solutions, it is ideal to store in a dry environment, such as a desiccator. Nevertheless, for best results with our aqueous solutions, we recommended utilizing the solutions within 3 months of purchase. Thereafter, the nanotubes and surfactant will begin to irreversibly aggregate to darkened spots and white strands, respectively.

Upon each purchased solution is a BIUB Code which aids in understanding the age of your solution. BIUB stands for “Best-If-Used-By” and is a date which represents the time 6 months after the production of a given material. Hence, if a material was produced on January 28, 2021 there will be a BIUB Code which states 210728. We recommend utilizing all purchased solutions no later than the BIUB date.

Can you offer your solutions in different concentrations?

Yes. However, we will add an additional fee for the increased processing time. Contact our sales manager to discuss: sales@nanointegris.com.

How do I remove the surfactants from your tubes?

Please review our standard surfactant removal instructions.

Do you sell functionalized CNTs?

We do not currently sell functionalized CNTs. However, several methods for functionalizing nanotubes have been reported in the literature which are compatible with our products. We suggest starting with the following review article for more information: Banerjee, S., et al., Advanced Materials (2005), 17, 17-29.

What is the length distribution of your nanotube products?

Our tubes range from approximately 300 nm to 5 microns in length. Detailed characterization information can be found in our technical data sheet.

Can you make your nanotubes shorter?

Yes. We can easily shorten our tubes via vigorous ultrasonication. If you are interested in shorter tubes, please contact our sales manager at sales@nanointegris.com.

Can you make your nanotubes longer?

This is an area of interest for many of our customers, particularly those developing applications that require a high degree of tube-tube contact (e.g., thin-films, transparent conductors, etc.). In brief, the answer is: no, we can’t currently do much to make our tubes longer. However, we’re working on it! If you would like to discuss this further, please contact us at info@nanointegris.com.

What is the diameter range of your nanotubes?

Our tubes range in diameter from 1.2 to 1.7 nm, with a mean diameter of approximately 1.4 nm. Detailed characterization information can be found in our technical data sheet.

Can you produce nanotubes with a narrower range (1.2 – 1.3 nm, for example)?

Yes, we are capable of diameter sorting. If this is of interest to you, please contact our sales manager to discuss: sales@nanointegris.com.

What chiralities are present in your nanotubes?

This is a difficult question to answer precisely, as the emission wavelengths of our tubes (approximately 1,500 to 2,300 nm) lie outside the range of most fluorescence detectors. It is reasonable, however, to assume that our products contain a relatively even distribution of all possible (metallic or semiconducting) chiralities that exist over their diameter range.

Can you sort nanotubes by chirality?

Yes, we are capable of chirality sorting. If this is of interest to you, please contact our sales manager to discuss: sales@nanointegris.com.

Do you acid treat your nanotubes to purify them?

No. Our IsoNanotubes and PureTubes are purified exclusively via non-chemical means.

Do your products contain residual catalyst impurities?

Our IsoNanotubes and PureTubes contain less than 1% catalyst by mass. Detailed characterization information can be found in our technical data sheet.

Do your products contain a lot of carbonaceous junk?

The amorphous carbon (i.e., non-nanotube) content of our IsoNanotubes and PureTubes is less than 5% by mass. Detailed characterization information can be found in our technical data sheet.

How do you quantify the metallic and semiconducting purity of your products?

We do this primarily via optical absorbance spectroscopy. Again, detailed characterization information can be found in our technical data sheet.