Anomalously enhanced light-emitting diode cooling via nucleate boiling using graphene-nanoplatelets coatings

Abstract

The efficacy of light-emitting diode cooling is anomalously augmented by deploying nucleate boiling on graphene-nanoplatelets coated surface at sub-atmospheric pressures. The thermal curing process makes the intrinsically hydrophobic graphene-nanoplatelets superhydrophilic. Nucleate boiling is significantly enhanced due to the ultrafast water permeation property of the cured superhydrophilic graphene-nanoplatelets. The ultrafast transport of water molecules through the nanostructures of graphene-nanoplatelets forms an ultrathin film of water that prompt effective absorption of latent heat of vaporization. Concurrent with the nanoporous structure of graphene-nanoplatelets, the nucleate boiling performance is significantly augmented due to the pronounced enhancement in the nucleation, growth, and departure rates of vapor bubbles. By benchmarking with the uncoated surface, the superhydrophilic graphene-nanoplatelets coated surface achieves a maximum enhancement in boiling heat transfer coefficient of 1178%, with a drastic temperature drop of 15.5 °C on the light-emitting diode surface. This translates into a substantially prolonged lifespan of the light-emitting diode. This study provides insightful information on the application of graphene coatings for a highly efficient and passive microelectronics cooling device.