New challenges and applications with our carbon nanotubes
Scientists are still finding new possibilities for this nanotechnology
It is hard to imagine nanotechnology and materials science without carbon nanotubes (CNTs) and their outstanding physical and chemical properties. 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.
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, optics and catalysis.
Strem Chemicals offers the following types of nanotubes:
- Arrays grown on 10x10x1mm quartz substrate using a single source CVD process that yields vertically aligned MWNTs (< 1% catalyst impurity). Arrays are 30µm (± 3µm) tall and are composed of MWNTs 100nm (± 10nm) in diameter .
- Produced by CVD. Typical metal content is <0.1%.
- Typical metal content is 4-5 wt %
- Contains 55-65 wt% nanotubes and 35-45wt% graphite nanoparticles. The tubes have a diameter distribution of 2-50 nm, and a typical length of >2 microns (straight tubes). The chemical composition is 100% carbon, with no metal impurities.
- Produced by cathode deposit, pieces
- Core material; pieces (20-40% nanotubes)
- -270 mesh powder (20-40% nanotubes)
- The tubes are 1-2nm in diameter with lengths of 5-30 microns. Ash is <1.5wt%.
- Science 2013, 339, 535
- Nature 1991, 354, 56
- Nature 1993, 363, 603
- Angew. Chem. Int. Ed. 2016, 55, 5136
- Chem. Rev. 2017, 117, 8041
- Adv. Drug Deliv. Rev. 2013, 65, 1933
- Chem. Soc. Rev., 2017, 46, 158
- Biosens. Bioelectron. 2017, 91, 15
- Sens. Actuators, B, 2015, 207, 690
- Acc. Chem. Res. 2017, 50, 435
- J. Energ. Chem. 2018, 27, 12
- Nanoscale, 2017, 9, 7342
- Science 2003, 300, 783
- Chem. Soc. Rev., 2015, 44, 3295
Mary Kedward Strem Chemicals UK Ltd
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