Chemical Engineering Journal, Vol.328, 609-618, 2017
Endowing the high efficiency thermally conductive and electrically insulating composites with excellent antistatic property through selectively multilayered distribution of diverse functional fillers
To fabricate thermally conductive while electrically insulating composites with excellent antistatic property is a huge challenge in the region of packaging materials of electronic devices due to the contradiction between the electrical insulation and the antistatic property. In the present work, the peculiar multilayer structures with alternating high efficiency thermally, electrically conductive layers and thermally conductive, electrically insulating layers were constructed successfully through a simple, one-step melt extrusion method. Such thermally conductive and electrically insulating composites possessed significant anisotropic electrical resistivity; for example, the in-plane electrical resistivities (parallel to the layer direction) were below 117 Omega x cm, while the through-plane electrical resistivities were over 5 x 10(13) Omega x cm. Meanwhile, with increasing the layer number, thermal conductivity of the composite with the same filler loading was improved monotonously, and reached as high as 1.45 W/(m x K) in the composite with 32 layers. In addition, tensile strength and elongation at break of the composites were also enhanced due to the different deformation mechanisms of separate layers. Furthermore, to give a deep insight into the enhancement mechanism of thermally conductive property, finite element analysis was applied and the results indicated that high efficiency thermally, electrically conductive layers possessed magnified effects on the heat dissipation. Therefore, the multilayer structure with alternating high efficiency thermally, electrically conductive layers and thermally conductive, electrically insulating layers can endow the composite with excellent comprehensive properties effectively, and it also sheds light on the design and fabrication of high performance materials for the applications of thermal management or other energy harvesting fields. (C) 2017 Elsevier B.V. All rights reserved.