An ultrahigh-thermal-conductivity, durable and multifunctional superhydrophobic coatings via molecular interface engineering of AlN on aluminum substrate for thermal management

The grafting mechanism of CTMS molecules on the AlN surface is systematically investigated. • H-AlN-C exhibits ultrahigh thermal conductivity (78.77  W/m·K). • H-AlN-C exhibits superhydrophobicity, along with excellent durability, self-cleaning, and anticorrosion properties. Developing multifunctional superhydrophobic coatings with high thermal conductivity remains a significant challenge due to the trade-off between surface wettability and efficient heat transfer. Bioinspired by the hydrolysis-prone nature of the aluminum nitride (AlN) surface, hexadecyltrimethoxysilane (CTMS) is covalently grafted onto AlN nanoparticles to construct a robust, multifunctional superhydrophobic coating (H-AlN-C) with high thermal conductivity. At high surface-modified AlN nanoparticles (H-AlN) loadings (90.9 wt%), H-AlN-C achieves an ultrahigh thermal conductivity of 78.77 W/m·K, while its abrasion resistance is relatively limited. In contrast, H-AlN-C with moderate H-AlN content exhibits a balanced performance, maintaining durable superhydrophobicity after 500 abrasion cycles together with a thermal conductivity of 7.1 W/m·K. Both coatings display high water contact angles (up to 171.9°), self-cleaning capability, and effective corrosion protection. Real-time thermocouple monitoring under cyclic heating–cooling conditions further verifies efficient and stable heat dissipation. MD simulations reveal that the reduced interfacial energy and lower diffusion coefficient of water clusters provide theoretical validation for superhydrophobic behavior of the H-AlN-C surface. These outstanding properties are enabled by the homogeneous dispersion and dense packing of H-AlN within the fluorocarbon resin matrix. Such interpenetrating architecture imparts both high surface roughness and low surface energy, enabling durable superhydrophobicity while supporting efficient heat dissipation. Download: Download high-res image (165KB) Download: Download full-size image