Urchin-inspired carbon-based 3D thermally conductive fillers for synergistic improvement of thermal conductivity and corrosion protection in composite coatings

The design of coatings that simultaneously exhibit high thermal conductivity and superior corrosion protection performance in extreme corrosive environments has garnered considerable interest in the academic community. However, constructing a continuous phonon conduction pathway within the coatings is extremely challenging. Inspired by the urchin structure, we developed a carbon-based three-dimensional thermally conductive network filler with the urchin-like morphology through a combination of in situ liquid-phase compounding, high-temperature pyrolysis, and self-assembly. This unique three-dimensional interconnected architecture enables continuous phonon conduction pathways that facilitate efficient thermal conduction while simultaneously reinforcing the “labyrinth” effect to suppress corrosive media permeation, thereby overcoming the intrinsic trade-off between thermal conductivity and corrosion protection. The as-prepared composite coating with a filler loading of 10 wt% delivers a 286% enhancement in thermal conductivity compared to the blank novolac epoxy (EPN) coating, while maintaining outstanding corrosion protection performance under harsh corrosive conditions. This research presents a unique method for designing and preparing composite coatings with high thermal conductivity and corrosion protection performance, thereby exhibiting significant potential for waste heat and water vapor recovery.