It is hard to imagine nanotechnology and materials science without carbon nanotubes (CNTs) and their outstanding physical and chemical properties.[1] The first fundamental studies on CNTs were reported by Iijima in the early nineties.[2, 3] CNTs are small tubular structures of two-dimensional graphene sheets, rolled into a cylindrical form. Similar to fullerenes, they have a honeycombed, net-like structure with six-membered sp²-hybridized carbon rings. There are three different forms of single-walled carbon nanotubes (SWCNTs) such as armchair, chiral, and zigzag.[4-5] The forms are dependent upon how the cylinders are wrapped.
CNTs may have many structures of different length, thickness, and number of layers, forming single-walled nanotubes (SWNTs) and multi-walled (MWNTs).(Fig. 1) SWNTs may have a diameter of about one nanometer. The diameter of the MWNTs may range from 50-100 nm with tube lengths from <100 nm to several centimeters. These variances in length, diameter, number of walls, opened or closed tube ends, all have a direct influence on the nanotubes’ mechanical, electrical, optical and thermal properties.
Figure 1: Schematic structure and TEM images of SWCNT and MWCNT
(reprint from Nanoscale Res. Lett. 2014, 9, 39)
Some CNT types can have extremely high surface areas and large aspect ratios. The tensile strength of CNTs is 100 times greater than that of steel; however, bulk nanotube materials may never achieve the same tensile strength of individual tubes. The electrical and thermal conductivities of CNTs are close to those of copper.
Current applications of nanotubes have been essentially limited rather unorganized fragments of nanotubes in bulk and thin films, having limited properties. Nevertheless, the unique properties of CNTs affords a great potential use in a wide variety of applications. These include biomedicine,[6-7] biosensors for cancer detection,[8-9] advanced energy conversion and storage,[10-11] nano- and microelectronics,[12] optics[13] and catalysis.[14]
Strem Chemicals offers the following types of nanotubes:
06-0504: Carbon nanotubes, multi-walled, as produced cathode deposit [308068-56-6]
06-0505: Carbon nanotubes, multi-walled, core material [308068-56-6]
06-0506: Carbon nanotubes, multi-walled, ground core material [308068-56-6]
06-0508: Carbon nanotubes, single-walled/double-walled, 90% [308068-56-6]
References:
Additional Resources:
Carbon-based Nanomaterials & Elemental Forms Booklet
Carbon Nanotubes Product Family