Enhanced thermal transport at covalently functionalized carbon nanotube array interfaces

It has been more than a decade since the experimental demonstration that the thermal conductivity of carbon nanotubes can exceed that of diamond, which has the highest thermal conductivity among naturally occurring materials. In spite of tremendous promise as a thermal material, results have been disappointing for practical thermal systems and applications based on nanotubes. The main culprit for the dramatic shortfall in the performance of nanotubes in practical systems is high thermal interface resistance between them and other components because of weak adhesion at the interface. Here we report a sixfold reduction in the thermal interface resistance between metal surfaces and vertically aligned multiwall carbon nanotube arrays by bridging the interface with short, covalently bonded organic molecules. These results are also significant for single and multilayer graphene applications, since graphene faces similar limitations in practical systems.