Exceptional Thermal Conductance across Hydrogen‐Bonded Graphene/Polymer Interfaces

Ineffective heat transfer between dissimilar materials of drastically different properties is a challenge for many areas including nanoelectronics and nanocomposites. Here, using atomistic simulations, it is demonstrated that the thermal conductance across the interfaces between graphene and poly(methyl methacrylate) (PMMA) can be improved by 273% by introducing hydrogen‐bond‐capable hydroxyl groups to the interfaces. Stronger than van der Waals interactions, the hydrogen bonds are found to improve the interfacial association, thereby enhancing the coupling of low‐frequency vibrational modes. Using the integrated autocorrelation of interfacial heat power, it is shown directly that the hydrogen bond donors, i.e., oxygen atoms in the hydroxyl groups, build the most effective thermal transport pathways at the graphene/PMMA interfaces. The enhanced interfacial thermal conductance is tunable in a wide range by varying the degree of functionalization, with an upper limit imposed by the saturation of hydrogen bonding. All these results suggest the design of “hydrogen‐bonded material interfaces” for drastically improving interfacial thermal transport toward a wide range of applications.