Introduction
A nanotube is a nanometer-scale tube-like structure. It is a kind of nanoparticle, and may be large enough to serve as a pipe through which other nanoparticles can be channeled or depend on the material, which can be used as an electrical conductor or an electrical insulator. The first nanotubes to be discovered were carbon nanotubes. Metal nanotubes as a kind of inorganic nanotubes, are morphologically similar to carbon nanotubes, which often composed of single-atom metals or metal oxides.
Fig 1 Structure of nanotubes
Metal nanotubes are alternative materials to better-explored carbon nanotubes. They have needle-like morphology and good adhesion to a number of polymers and high impact-resistance, showing advantages such as easy synthetic access, high crystallinity, predefined electrical conductivity, good uniformity and dispersion. They are therefore promising candidates as fillers for polymer composites with enhanced thermal, mechanical, and electrical properties.
Applications
Fig 2 Gold nanotubes are applied to in cancer treatment
(Adv. Funct. Mater. 2015, DOI: 10.1002/adfm.201404358)
Gold nanotubes: Gold nanotubes have the potential to enhance the efficacy of these conventional treatments and were applied in medical treatment. When the gold nanotubes travel through the body, they can absorb the right frequency light shone on them, and convert this light energy to heat, which raises the temperature in the vicinity of the nanotubes to destroy cancer cells (Fig 2).
Titanium dioxide nanotubes: Titanium dioxide nanotubes have not only excellent photocatalytic property but also high capability for the molecule adsorption as a single phase material. They are regarded as an excellent candidate for the advanced high-performance environmental purification system.
Boron nitride nanotubes: Boron nitride nanotubes show promise for aerospace applications. Integrating nitride nanotubes boron and in particular the light isotope of boron (10B) into structural materials, can improves both their strength and radiation-shielding properties.
Copper-carbon nanotubes: Copper-carbon Nanotubes are promising materials with extra ordinary electrical, mechanical and thermal properties and are considered suitable for electronic packaging either in its pure form or as fillers for composites.
