Boron nitride nanotube precursor formation during high-temperature synthesis: kinetic and thermodynamic modelling.

We performed integrated modelling of the chemical pathways of formation for boron nitride nanotube (BNNT) precursors during high-temperature synthesis in a B/Nmixture. Integrated modelling includes quantum chemistry, Quantum-classical molecular dynamics, thermodynamic modelling, and kinetic approaches. We demonstrate that BN compounds are formed via the interaction of molecular nitrogen with small boron clusters, rather than through interactions with less reactive liquid boron.

Convenient analytical formula for cluster mean diameter and diameter dispersion after nucleation burst.

We propose an alternative method of estimating the mean diameter and dispersion of clusters of particles, formed in a cooling gas, right after the nucleation stage. Using a moment model developed by Friedlander [S. K.

Determining the gas composition for the growth of BNNTs using a thermodynamic approach.

High-yield production of high-quality boron-nitride nanotubes (BNNTs) has been reported recently in several publications. A boron-rich material is evaporated using a laser or plasma in a nitrogen-rich atmosphere to supply precursor gaseous species for nucleation and growth of BNNTs. Either hydrogen was added or pressure was increased in the system to achieve high yield and high purity of the synthesized nanotubes.