SWBNNTs

SWBNNTs, or single-walled boron nitride nanotubes, are cylindrical nanostructures formed by rolling a single sheet of hexagonal boron nitride into a seamless tube. They are isostructural with single-walled carbon nanotubes, but their lattice consists of alternating boron and nitrogen atoms, yielding a different electronic landscape.

Although similar in shape to carbon nanotubes, SWBNNTs are wide-band-gap insulators, with a band gap around 5 to 6 eV that is largely independent of tube chirality or diameter. They possess high thermal conductivity along the tube axis and notable chemical and thermal stability, making them resistant to oxidation at elevated temperatures. They also combine good mechanical strength with a low density, contributing to favorable performance in composite materials.

Common synthesis methods include chemical vapor deposition, laser ablation, and arc-discharge techniques, using boron- and nitrogen-containing precursors such as borazine or ammonia borane. Transition-metal catalysts are typically employed, and achieving uniform diameters, chirality, and high yields remains challenging.

Potential applications span dielectric components in nanoelectronics, reinforcing agents in polymer and ceramic composites, high-temperature insulators, and neutron- or radiation-shielding materials due to the boron content. Their insulating character and thermal properties make them attractive for integrated nanostructures where electrical isolation is required.

Compared with SWCNTs, SWBNNTs offer predictable insulating behavior rather than metallic or semiconducting conductance. Research continues to address synthesis scale, purity, chirality control, and cost, as well as integration into devices and composites.