Remarkably anisotropic conductive MWCNTs/polypropylene nanocomposites with alternating microlayers

Multilayered objects are some of the most common composites in nature with outstanding performance that cannot be achieved by a single component. To expand the application of multilayered composites with excellent anisotropic properties, facile and environmental friendly fabrication methods and low-cost raw materials are unambiguously required. The Chinese traditional food called "thousand-layer pie" is an example of such composites with multilayered structure, showing visual attractiveness and having delicious taste. Borrowing the idea from the method of preparing this food, anisotropic conducive polymer composites (ACPCs) with alternating microlayers of pure polypropylene (PP) and PP filled multi-walled carbon nanotubes (PPCNTs) were prepared by a combined polymer melt processing technique. The multilayered structure endowed the ACPCs with inner layer conduction but interlayer insulation. The electrical conductivity in X direction reached up to 1 S/m and exhibited a value almost 16 orders of magnitude higher than the value in Z direction, which was by far the most remarkable conducive anisotropy compared with the reported counterparts. The anisotropic functionality of the ACPCs enabled them to be used in electrical and thermal management applications, such as subminiature integrated circuits, highly reliable electrical interconnects and anisotropic thermal conduction. Considering the low-cost raw materials used and the facile preparation process, this approach can be scaled up for industrial production, promoting such ACPCs with high performance and functionality to be implemented in a variety of applications.