A versatile multilayer interwoven order-structured carbon-based building block for efficient heat dissipation

The design and construction of microstructures and nanostructures are crucial for regulating and enhancing phonon transport. Optimizing the heat dissipation and reducing the phonon scattering of hierarchical carbon-based anisotropic building blocks in the in-plane and/or through-plane directions is challenging. In this study, two types of multilayer interwoven order-structured carbon-based building blocks (DD/SDS) were fabricated using the ordered assembly of single/double-layer vertically arranged carbon nanotube arrays and flexible graphite paper (GP). The results show that the design and construction of multilayer order-structured are crucial for regulating in-plane and through-plane heat conduction. The different interlayer interwoven structures of DD and SDS generated two dominant modes of through-plane and in-plane heat conduction, respectively; these modes can be regulated within the 16.6 to 35.1 W/mK and 164.4 to 300.0 W/mK ranges. SDS exhibited tensile (5.4 MPa) and bending (30.0 MPa) strengths that were higher than those of DD (tensile strength of 3.8 MPa and bending strength of 28.0 MPa) because of the combined effect of the high strength of its three-layer GP and its interwoven nanotubes. These carbon-based building blocks as versatile heat dissipation boards the efficient heat dissipation requirements of point heat sources across varying power densities owing to their diverse and controllable heat conduction modes. They can also be applied in the cooling field of high-power light-emitting diode chips and alumina ceramic heating elements. Results showed that the cooling efficiency of SDS and DD is 33% and 72% higher than that of Si₃N₄, respectively.