Chen Jin, Wei Han, Bao Hua, Jiang Pingkai, Huang Xingyi
Department of Polymer Science and Engineering, Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing , Shanghai Jiao Tong University , Shanghai 200240 , China.
University of Michigan-Shanghai Jiao Tong University Joint Institute , Shanghai Jiao Tong University , Shanghai 200240 , China.
ACS Appl Mater Interfaces. 2019 Aug 28;11(34):31402-31410. doi: 10.1021/acsami.9b10810. Epub 2019 Aug 16.
Increasing power density makes modern electronic devices and power equipment generate excess heat, which greatly restricts the applications of polymeric materials because of their poor thermal conductivity. In the present work, inspired by the structure and production process of millefeuille cakes, we show that electrostatic spraying of boron nitride nanosheets (BNNSs) onto electrospun poly(vinyl alcohol) (PVA) nanofibers can produce highly thermally conductive, electrically insulating, flexible, and lightweight nanocomposites via a scalable method of building a multilayer PVA/BNNS nanonetwork structure. The PVA/BNNS nanocomposites exhibit an ultrahigh in-plane thermal conductivity of 21.4 W/(m·K) at 22.2 vol % BNNS addition, realized by an orientated BNNS network structure with overlapping interconnections. The BNNS networks exhibit low thermal resistance and interfacial heat scattering between BNNSs. Moreover, for heat dissipation applications, the nanocomposites with an overlapping BNNS network show higher efficiency in dissipating hot spots than randomly dispersed BNNS or directly hot-pressed BNNS composites. These PVA/BNNS nanocomposites can be used as high-performance lateral heat spreaders in next-generation thermal management systems.
功率密度的不断提高使得现代电子设备和电力设备产生过多热量，这极大地限制了聚合物材料的应用，因为它们的热导率很差。在本工作中，受千层饼的结构和生产工艺启发，我们表明，通过一种可扩展的构建多层PVA/BNNS纳米网络结构的方法，将氮化硼纳米片（BNNSs）静电喷涂到电纺聚（乙烯醇）（PVA）纳米纤维上，可以制备出具有高导热性、电绝缘性、柔韧性和轻质的纳米复合材料。在添加22.2体积%的BNNS时，PVA/BNNS纳米复合材料表现出21.4W/（m·K）的超高面内热导率，这是通过具有重叠互连的取向BNNS网络结构实现的。BNNS网络在BNNS之间表现出低热阻和界面热散射。此外，对于散热应用，具有重叠BNNS网络的纳米复合材料在消散热点方面比随机分散的BNNS或直接热压的BNNS复合材料具有更高的效率。这些PVA/BNNS纳米复合材料可作为下一代热管理系统中的高性能横向散热器。
