Oriented SiO2-modified Al flake/SiC nanowire hybrid networks with interfacial regulation for highly thermally conductive silicone rubber composites

Ice-templated assembly can organize two-dimensional and one-dimensional fillers into oriented networks, providing an effective strategy for constructing thermally conductive pathways in polymer composites. However, conventional two-dimensional fillers, such as graphene and MXene, are prone to curling, restacking, and aggregation, which compromises network continuity and thermal transport efficiency. In contrast, Al flakes possess high thermal conductivity, a high aspect ratio, and resistance to curling, but their surface oxidation and poor water dispersibility limit their application in ice-templated assembly. Herein, surface modification with silicon dioxide (SiO 2 ) was first introduced onto Al flakes to improve their dispersibility in water and mitigate surface oxidation. The resulting flakes (Al@SiO 2 ) were then combined with silicon carbide nanowires (SiCNWs) to form oriented hybrid filler networks in silicone rubber (SR) through ice-templated assembly, followed by interfacial modification using a polysiloxane-based modifier. The best-performing composite achieved a through-plane thermal conductivity of 4.49 W·m −1 ·K −1 at an Al@SiO 2 /SiCNW loading of 6.54 wt% (2.60 vol%). Theoretical modeling evaluated the contribution of Al@SiO 2 flakes and SiCNWs to thermal transport, while finite-element simulations confirmed that the oriented hybrid networks promoted continuous heat transfer. The composites also exhibited excellent heat-dissipation capability and thermal stability. This work provides an effective strategy for constructing highly efficient thermally conductive networks in polymer composites. Download: Download high-res image (223KB) Download: Download full-size image