Abstract: The introduction of carbon nanomaterials, such as graphene, in the resin matrix can significantly improve the mechanical properties, thermal conductivity and versatility of the composites, consequently introducing innovation into the traditional composites. The orientation of nanomaterial in composites will directly affect the properties of the composites. According to the data in literatures, compared to randomly oriented nanocomposites, the strength of graphene/polymer composites reinforced with aligned graphene is 50% higher, and the thermal conductivity of those is approximately 100% higher. What is more, the aligned graphene reinforced polymer composites can see an increase in toughness by approximately 1.2 times compared to randomly aligned graphene reinforced polymer composites. In this regard, this paper summarizes the preparation methods of aligned-graphene/polymer composites, including layer-by-layer self-assembly method, flow-shear induced orientation method, vacuum-assisted self-assembly method, external field induced orientation method, etc., and briefly describes the advantages and disadvantages of each preparation method. The enhancement in the mechanical property, thermal conductivity and electrical conductivity of the composites caused by aligned graphene is analyzed. On this basis, the development and prospects of the development of aligned-graphene/polymer nanocomposites are discussed.

Key words: alignment, graphene, polymer composites