Learning from Natural Nacre: Constructing Layered Polymer Composites with High Thermal Conductivity

Inspired by the microstructures of naturally layered and highly oriented materials, such as natural nacre, we report a thermally conductive polymer composite that consists of epoxy resin and Al₂O₃ platelets deposited with silver nanoparticles (AgNPs). Owing to their unique two-dimensional structure, Al₂O₃ platelets are stacked together via a hot-pressing technique, resulting in a brick-and-mortar structure, which is similar to the one of natural nacre. Moreover, the AgNPs deposited on the surfaces of the Al₂O₃ platelets act as bridges that link the adjacent Al₂O₃ platelets due to the reduced melting point of the AgNPs. As a result, the polymer composite with 50 wt % filler achieves a maximum thermal conductivity of 6.71 W m^-1 K^-1. In addition, the small addition of AgNPs (0.6 wt %) minimally affects the electrical insulation of the composites. Our bioinspired approach will find uses in the design and fabrication of thermally conductive materials for thermal management in modern electronics.