Co-growing design of super-repellent dual-layer coating for multiple heat dissipation improvement

Abstract Multi-mode heat dissipation is a promising approach for more efficient thermal management. Nevertheless, a simultaneous demonstration of multiple heat dissipation along with mechanochemical stability is challenging. Herein, a novel super-repellent dual-layer coating (SDC) has been fabricated via plasma-induced high temperature liquid-phase assisted oxidation and deposition technique. Based on the optimal adjustment of organic–inorganic multilayer structure, a thin polymer-like layer with hierarchical structures was constructed on the Al2O3 ceramic bottom skeleton, endowing the coating with multiple heat dissipation and mechanochemical robustness. The incorporation of organic nanoparticles not only gives the superhydrophobicity of coating by adjusting surface roughness, but also promotes the passive radiative heat dissipation. Accordingly, the dual-layer coating exhibits enhanced emissivity (>0.8) over the thermal wavelength range, due to the Al2O3 lattice absorption as well as vibration and rotation of the functional group of polymer-like layer assisted further by micro/nanostructure’s infrared trapping effect, thereby reducing the temperature to 9.5 °C for 5 W power LED. Simultaneously, the rapid liquid circulation in superhydrophobic microchannels is directly embedded inside the radiators, further boosting cooling efficiency. Moreover, after prolonged exposure to highly corrosive media (aqua regia, NaOH and NaCl), the super-repellent dual-layer coating shows excellent chemical stability. Meanwhile, the samples present enticing mechanical durability (>60 cycles), environmental stability (>120 days), thermal cycling stability (up to 400 °C) and self-cleaning function. Notably, the coating has superior electrical properties to meet the insulation shielding requirements of overall package structure. This work not only affords multi-mode heat dissipation for large power devices to achieve more sustainable cooling, but also paves a new way to design and fabricate multi-functional integrated electronic packaging materials.