Wood annual ring structured elastomer composites with high thermal conduction enhancement efficiency

The construction of heat conduction pathways in a polymer matrix is crucial for improving the thermal management performance of polymer composites. Three-dimensional thermally conducive scaffolds with highly aligned filler structures are attractive to construct rapid conduction pathways in polymer composites. A typical example is the xylem issue in tree trunks, although it is to transport water and nutrients upward. Herein, inspired by the annual ring structure of natural trees, a thermal conducive carbon nanotubes-based skeleton (T-SGM) with long-range ordered microstructures was developed through combining one-dimensional carbon nanotubes and two-dimensional graphene oxide sheets in alkaline conditions, assisted by a combined drying method. After the incorporation of T-SGM into polydimethylsiloxane resin, wood annual ring structured composites were prepared and they can exhibit a through-plane thermal conductivity enhancement of similar to 744% at a low skeleton content of 6.0 vol%. In addition, the excellent resilience of the composites is still maintained. The infrared thermal imaging results demonstrated that wood annual ring structured composites have high potential in thermal management applications.