Who: UC Riverside, Moldova State University, and Graphenea
What: Reducing graphene oxide to graphene via a high-temperature treatment increases thermal conductivity along the film direction, while decreasing it across the film. Graphene possesses an extremely high thermal conductivity along the sheet plane, making it a candidate for thermal management applications, for example as a filler in thermal interface materials, or as a flexible heat spreader for cooling today’s demanding electronics. One of the most researched forms of graphene for industrial applications is graphene oxide (GO), a material produced with scalable and rather inexpensive methods. Having demonstrated excellent mechanical properties, GO has trailed behind other forms of graphene in electrical performance and in thermal conductivity. Current research shows that thermal conductivity of GO can be increased nearly 30 times by bringing GO to a high temperature during a reduction process.
GO, when heated to 1000°C, turns to reduced GO (rGO) that has a high thermal conductivity along the sheet plane. In contrast, thermal conductivity perpendicular to the sheet shows an opposite trend, decreasing with thermal treatment. This seemingly confusing conclusion is elegantly explained with detailed characterization and theoretical support.
Image: Sketch of air pockets impeding heat transport perpendicular to the graphene sheets, and a SEM image of the same.
this new material holds much promise for thermal management applications where one would want to remove excess heat along one direction while shielding from heat along the perpendicular direction.
Where: Thermal management.
When: This new material holds much promise for thermal management applications where one would want to remove excess heat along one direction while shielding from heat along the perpendicular direction.
Reference “Strongly Anisotropic Thermal Conductivity of Free-Standing Reduced Graphene Oxide Films Annealed at High Temperature” Wiley Advanced Functional Materials.
