Boron Nitride Nanotube Films Grown From Boron Ink Painting

TL;DR

This paper introduces a simple boron ink painting technique for growing high-density boron nitride nanotube films on various complex surfaces, enabling diverse applications in nanodevices and materials.

Contribution

The method allows for patterning BNNT films on arbitrary surfaces using ink painting and annealing, expanding BNNT applications to non-flat and complex geometries.

Findings

BNNT films can be grown on complex surfaces like steel meshes and screws.

The method enables patterning BNNTs with desired designs.

BNNT coatings improve microfluidic transport and reduce wear.

Abstract

The growth of nanotube films on various substrates and surfaces is vital for applications in nanoscale functional devices. We report a simple and versatile boron (B) ink painting method that enables high-density boron nitride nanotube (BNNT) films with any desired pattern to be grown on, and firmly attached to, different surfaces. In the method, special B ink is first painted, sprayed or inkjet printed at desired location with required pattern, and then the ink layer is annealed in a nitrogen-containing atmosphere to form BNNT film. The B ink is a liquid mixture of ball-milled B particles, metal nitrate and ethanol. This is the first method capable of growing BNNTs on complex non-flat surfaces, which greatly broadens the potential application of BNNTs. For example, it is demonstrated that a BNNT coated steel mesh can separate water and oil on a microliter scale; a needle given an internal BNNT coating could greatly enhance microfluidic transport; and a coated screw could be used to minimize wear at the interface.