Carbon nanotubes (CNTs) are allotropes of pure carbon. A single walled CNTs (SWCNTs) consist of one sheet of graphite rolled up into cylindrical tube, and multiwalled carbon nanotubes (MWCNTs) are constructed of many graphite layers rolled in on themselves to form long multicylinder. The interlayer distance in MWCNTs is estimated for 0.34 nm. Theoretically, we may distinguish different kinds of carbon nanotubes due to their structure (zigzag, armchair and chiral), synthesis (CVD, laser ablation, arc discharge), they can be capped or open, raw or purified, ideal or defected, empty or filled with other material, noncovalently or covalently modified.
In carbon nanotubes the length-to-diameter ratio exceeds sometimes 10 000. Such carbon nanotubes material exhibits very interesting novel properties, which can create a wide variety of new applications in material science, physics, chemistry, medicine and nanotechnology. Unique electrical and heat conductivity, mechanical strength make them novel material of the 21st century.
To find serious commercial applications for carbon nonmaterial CNTs are usually modified in a different way. We may use physical or chemical treatments to change CNTs properties entirely. Physical modification usually based on noncovalent interactions of doping material with carbon materials (by Wan der Waals forces). Organic or inorganic materials can be placed outside or inside the empty CNTs channel. However, chemical modifications can create covalent bonding of chemical groups (such as: -COOH, -OH, -NH2, =CO, -NO2, -SO3H, etc.) with the tube ends and CNTs wall. The chemical groups can enhance the wetting properties of CNTs in many polar solvents and can induce high dispersion of CNTs inside other matrix materials, such as polymers, metals, textiles, etc.
Author of this work will demonstrate physically and chemically modified CNTs based on own studies and results.