NASA’s Langley Research Center has developed a method for exfoliating commercially available hexagonal Boron Nitride (hBN) into nanosheets a few atomic layers thick. Currently, hBN has limited use because it is insoluble with limited dispersibility, despite hBN having excellent thermal conductivity and electrical insulation. Langley’s novel method provides for exfoliated hBN nanosheets that are soluble or suspendable in a variety of solvents, allowing for their bulk preparation and incorporation into composites, coatings, and films.
The invented method involves mechanical breakdown of large hBN particles followed by chemical functionalization to achieve exfoliation of the hBN sheets. The exfoliated hBN nanosheets are one or a few atomic layers thick, and dispersible (or suspendable, soluble) in common organic solvents and/or water, depending upon the nature of the functionalities. The functionalities can be subsequently removed by thermal treatment, with the hBN nanostructures remaining intact and exfoliated.
This is the first method to produce solution-processible exfoliated hBN nanostructures in bulk quantities. It is a simple, cost efficient, and scalable method using commercially available hBN. The exfoliated hBN is thermally conductive and electrically insulating.
This technology can be used in microelectronics, advanced composites, and biomedical applications.