Ultra-High Thermal Conductivity Polyethylene Nanofibers

Highly stretched polyethylene nanofibers are demonstrated to have thermal conductivities as high as ∼ 100 W/m.K along the fiber direction, which is comparable to many metals and is 3 orders of magnitude larger than the typical thermal conductivity of bulk polymers. The high thermal conductivity is attributed to the restructure of polymer chains in nanofibers by stretching, which improves the fiber quality toward the “ideal” single crystalline fibers. Our results suggest that high thermal conductivity polyethylene nanofibers may be able to serve as a cheaper alternative to conventional metal-based heat transfer materials in a wide range of applications.