School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalizaion for Inorganic Materials, Shaanxi University of Science & Technology, Xi' an, Shaanxi 710021, P. R. China.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China.
ACS Appl Mater Interfaces. 2023 Jun 7;15(22):27223-27233. doi: 10.1021/acsami.3c04799. Epub 2023 May 23.
With the rapid development of miniaturization and high-power portable electronics, the accumulation of undesired heat can degrade the performance of electronic devices and even cause fires. Therefore, multifunctional thermal interface materials that combine high thermal conductivity and flame retardancy remain a challenge. Herein, an ILC (ionic liquids crystal)-armored boron nitride nanosheet (BNNS) with flame retardant functional groups was first developed. The high in-plane orientation structure aerogel film made of such an ILC-armored BNNS and aramid nanofiber and polyvinyl alcohol matrix through directional freeze-drying and mechanical pressing exhibits strong anisotropy thermal conductivity (λ of 17.7 W m K and λ of 0.98 W m K). In addition, the highly oriented IBAP aerogel films have excellent flame retardancy (peak heat release rate = 44.5 kW/m and heat release rate = 0.8 MJ/m) due to the physical barrier effect and catalytic carbonization effect of ILC-armored BNNS. Meanwhile, IBAP aerogel films exhibit good flexibility and mechanical properties, even in harsh environments such as acids and bases. Further, IBAP aerogel films can also be used as a substrate for paraffin phase change composites. The ILC-armored BNNS provides a practical way to produce flame-resistant polymer composites with high thermal conductivity for TIMs in modern electronic devices.
随着小型化和高功率便携式电子产品的快速发展，不期望的热量积累会降低电子设备的性能，甚至引发火灾。因此，将高热导率和阻燃性结合在一起的多功能热界面材料仍然是一个挑战。在此，首次开发了一种带有阻燃官能团的 ILC（离子液体晶体）包覆氮化硼纳米片（BNNS）。通过定向冷冻干燥和机械压制，由这种 ILC 包覆 BNNS 和芳纶纳米纤维以及聚乙烯醇基体组成的高面内取向结构气凝胶薄膜表现出强各向异性热导率（λ为 17.7 W m K，λ为 0.98 W m K）。此外，由于 ILC 包覆 BNNS 的物理阻挡效应和催化碳化效应，高度取向的 IBAP 气凝胶薄膜具有优异的阻燃性（峰值放热率 = 44.5 kW/m 和放热率 = 0.8 MJ/m）。同时，IBAP 气凝胶薄膜具有良好的柔韧性和机械性能，即使在酸和碱等恶劣环境下也是如此。此外，IBAP 气凝胶薄膜还可用作石蜡相变复合材料的基板。ILC 包覆 BNNS 为制备用于现代电子设备中 TIMs 的具有高热导率和阻燃性的聚合物复合材料提供了一种实用方法。
