Boron nitride nanotubes (BNNTs) have a similar tubular structure

Boron nitride nanotubes (BNNTs) have a similar tubular structure as carbon nanotubes in which carbon atoms are replaced entirely by boron and nitrogen atoms, arranged in a hexagonal lattice. Not surprisingly, because of this similarity, both BNNTs and CNT share some identical intrinsic characteristics, such as excellent mechanical properties, high thermal conductivity. Their Young's modulus was experimentally measured at a TPa level. Although having smaller Young's modulus and yield strength than those for CNTs, BNNTs were predicted to be thermo-mechanically stable at high temperatures. Also, compared to CNTs, BNNTs have similar thermal conductivity and oxidation resistance (up to 900 °C). On the contrary, while CNTs are semimetallic and semiconducting materials, BNNTs are excellent insulators with a wide bandgap (5–6 eV). The bandgap of BNNT is not dependent on nanotubes' diameter and chirality-geometrical information but is particularly vulnerable to doping and functionalization. The contradiction in electronic property is knowingly attributed to the B–N bond polarity caused by the difference in electronegativity of boron (2.04) and nitrogen (3.04). Extraordinary and yet distinct characteristics of BNNT have triggered great interest in fundamental studies on the properties and applications of this new exotic material. However, unlike research in CNTs which has been well-established for over a decade, the study on BNNT is still immature and far less developed than the carbon counterpart. The reason for this situation lies in the synthesis of BNNT, which remains a significant challenge since BNNT was first discovered in 1995. Whereas high-quality CNT can be easily produced in a laboratory with simple equipment, BNNT synthesis requires specially designed apparatus in extreme conditions. The lack of an efficient synthesis route combining with the high price of readily commercial products could seriously hinder the study of BNNT in the long term. Many remarkable successes in BNNT synthesis have been recently achieved utilizing newly developed and novel techniques. Large quantities and high quality of BNNT are now becoming accessible, and in turn, this will gradually foster the BNNT research field. This review will present BNNT synthesis methods currently widely used and applications of BNNTs in various areas. If you are looking for high quality, high purity, and cost-effective Boron Nitride, or if you require the latest price of Boron Nitride, please feel free to email contact mis-asia.