Polymer–metal composite materials have been extensively employed for thermal management in the electronic field. However, their application is hindered by limited thermal conductivity and inadequate electrical insulation. In this study, we present a novel strategy to prepare advanced polymer–metal films by incorporating cellulose nanofibers (CNFs) with orientated polydopamine (PDA) modified aluminum (Al) flakes, employing a straightforward process involving vacuum-assisted filtration and hot-pressing. The resulting Al@PDA/CNF films exhibited a superior in-plane thermal conductivity of 22.9 W/(m·K) and electrical resistivity of 1.6 × 10¹⁶ Ω·cm, outperforming the Al/CNF films. Molecular dynamics simulation results showed that the interfacial interaction between Al and CNF was greatly improved by the hydrogen-bonding interaction with coated PDA, which acts as a “bridge” to promote phonon vibration matching, resulting in excellent heat transfer and electrical insulation properties. Our study provides a promising approach for the preparation of high-performance polymer–metal thermal interface materials (TIMs) with insulation, demonstrating great potential in thermal management applications.

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通过界面改性提高导热性：聚合物-金属薄膜的实验和理论验证

聚合物金属复合材料已广泛应用于电子领域的热管理。然而，它们的应用受到有限的导热性和不足的电绝缘性的阻碍。在这项研究中，我们提出了一种新颖的策略，通过将纤维素纳米纤维（CNF）与定向聚多巴胺（PDA）改性铝（Al）片相结合，采用真空辅助过滤和热压的简单工艺来制备先进的聚合物金属薄膜。所得的Al@PDA/CNF薄膜表现出优异的面内热导率（22.9 W/(m·K)）和电阻率1.6×10 ¹⁶ Ω·cm，优于Al/CNF薄膜。分子动力学模拟结果表明，Al和CNF之间的界面相互作用通过与涂层PDA的氢键相互作用得到极大改善，充当“桥梁”促进声子振动匹配，从而产生优异的传热和电绝缘性能。我们的研究为制备具有绝缘功能的高性能聚合物-金属热界面材料（TIM）提供了一种有前途的方法，展示了在热管理应用中的巨大潜力。