Scalable manufacturing of boron nitride nanotubes and their assemblies: a review

Abstract

Boron nitride nanotubes (BNNTs) are wide bandgap semiconducting materials with a quasiparticle energy gap larger than 6.0 eV. Since their first synthesis in 1995, there have been considerable attempts to develop novel BNNT-based applications in semiconductor science and technology. Inspired by carbon nanotube synthesis methods, many BNNT synthesis methods have been developed so far; however, it has been very challenging to produce BNNTs at a large scale with the structural quality high enough for exploring practical applications. Very recently there has been significant progress in the scalable manufacturing of high-quality BNNTs. In this article, we will review those particular breakthroughs and discuss their impact on semiconductor industries. Freestanding BNNT assemblies such as transparent thin films, yarns or buckypapers are highly advantageous in the development of novel BNNT-based semiconductor devices. The latest achievements in their manufacturing processes will be also presented along with their potential applications.

Single- and double-walled boron nitride nanotubes: Controlled synthesis and application for water purification

“…BNNTs and h-BN consist of boron and nitrogen covalently bonded in a honeycomb lattice and are structurally very similar to CNTs and graphene [10][11][12][13][14][15] . While carbon-based materials have high electrical conductivities due to the overlap of π orbitals 16,17 , BNNTs and h-BN composed of boron and nitrogen atoms are nearly insulators with ~5.8 eV bandgaps due to electron separation arising from the high electronegativity of the nitrogen atom 11,13,15,19,20,18,10 . In particular, BNNT has not only the unique 1D structure stable up to a temperature of 850 °C but also their superior mechanical properties and chemical resistance 7,9,10,19,[21][22][23] .…”

“…While carbon-based materials have high electrical conductivities due to the overlap of π orbitals 16,17 , BNNTs and h-BN composed of boron and nitrogen atoms are nearly insulators with ~5.8 eV bandgaps due to electron separation arising from the high electronegativity of the nitrogen atom 11,13,15,19,20,18,10 . In particular, BNNT has not only the unique 1D structure stable up to a temperature of 850 °C but also their superior mechanical properties and chemical resistance 7,9,10,19,[21][22][23] . Therefore, BNNTs among BN materials have been applied to various applications, such as BNNT-polymer composites, BNNT-metal composites, and biological applications 7,9,10,12,15,21,[24][25][26][27][28][29][30][31][32][33] .…”

Thermal Plasma Synthesis of Ceramic Nanomaterials

“…-High energy density in a small volume of plasma -High rate of chemical reaction for high productivity -The stationary heating of gas to the mean temperature up to 20,000 K -The heating of almost all gases: for reduction, oxidation, inert gases, and mixtures -No limitation of precursors: solid, liquid, or gas precursors -Solvent-free dry processing In addition, the characteristics of manufactured nanomaterials such as morphology, crystallinity, crystal phase and size can be controlled through the generation conditions of the plasma or processing variables [16 19]. Recently, there have been many efforts to implement mass production of nanomaterials using the thermal plasma process [20,21].…”

Boron Nitride Nanotube Cyclotron Targets for Recoil Escape Production of Carbon-11

“…Boron nitride nanotube (BNNT) nanomaterials [1][2][3][4][5] can be used in a recoil escape target to produce 11 C for incident proton energy at or below 11 MeV. This would enable 11 C production for economical low-energy cyclotrons [6][7][8][9], and it could be used to increase production from conventional 11 C gas targets on MiniTrace and RDS-111 cyclotrons.…”