The miniaturization, integration, and lightweight of modern electronics have posed serious challenges to the development of high-performance and multifunctional thermal management materials. Here, we reported SiO₂-coated nanofibrillated cellulose (NFC)/boron nitride nanosheets (BNNS) hybrid films with excellent thermal conductivity (TC) and hydrophobicity. These films were easily constructed via vacuum-assisted filtration and subsequent hydrophobic coating. The hybrid films exhibit a well-defined aligned structure with in-plane oriented BNNS. This finding was proven via wide-angle and small-angle X-ray scattering techniques, allowing for a high TC of up to 10.88 W m⁻¹ K⁻¹ at a low BNNS content of 7 wt%. Moreover, the hydrophobic hybrid films achieve high tensile strength (166.47 MPa) and electrical insulating property (volume resistivity = 1.2 × 10¹² Ω cm). Inspired by the lotus effect, the water contact angle of such hydrophobic hybrid films reaches 143°, showing great potential in real applications for preventing the adverse effects of water and moisture.

现代电子产品的小型化，集成化和轻量化对高性能和多功能热管理材料的开发提出了严峻挑战。在这里，我们报道了具有优异的导热性（TC）和疏水性的SiO ₂涂层纳米原纤化纤维素（NFC）/氮化硼纳米片（BNNS）杂化膜。这些膜很容易通过真空辅助过滤和随后的疏水涂层进行构建。杂化膜表现出具有面内定向的BNNS的明确定义的对准结构。通过广角和小角X射线散射技术证明了这一发现，可实现高达10.88 W m ^-1  K ^-1的高TCBNNS含量低至7 wt％。此外，疏水性杂化膜达到高的拉伸强度（兆帕166.47）和电绝缘性（体积电阻率= 1.2×10 ¹²  Ω厘米）。受荷叶效应的启发，这种疏水性杂化膜的水接触角达到143°，在防止水和湿气的不利影响的实际应用中显示出巨大的潜力。