Shape, not just size, can matter when it comes to thermal conductivity at the nanoscale.
A new study shows that nanoribbons made of boron have unusually strong heat-transfer properties compared to other wire/tube-like nanomaterials. The finding contrasts today’s ‘common wisdom’ that bundles of non-metallic nanostructures are less effective in conducting heat than single nanostructures.
The study found "the thermal conductivity of a bundle of boron nanoribbons can be significantly higher than that of a single free-standing nanoribbon." The research implies “achieving a tight van der Waals interface between the ribbons is important in thermal conductivity, something their geometry encourages," said team member Terry Xu of the University of North Carolina at Charlotte. "It is possible that this result may have implications for other materials with ribbon-based nanostructures," Xu added. The team also found the boron nanoribbon bundles heat transfer properties could be modified, allowing thermal conductivity to be switched on and off.
The work is published in the online journal Nature Nanotechnology. Aside from a team from UNC Charlotte, the team included researchers from Vanderbilt University, Lockheed Martin Space Systems, the U.S. Department of Defense Advanced Research Projects Agency and Southwest University (Nanjing, China).