Mussel-like carbon fiber/MnO2 nanosheet heterostructures for mechanically strong carbon fiber/polyamide composites with excellent electromagnetic interference shielding

Abstract

In order to construct carbon fiber (CF) reinforced polyamide 6 (PA6) composites with both excellent mechanical properties and electromagnetic interference (EMI) shielding properties, in this paper, a multiscale coating of PDA-MnO2 is constructed on the CF surface based on the in-situ growth process of polydopamine (PDA) and δ-phase manganese dioxide (δ-MnO2) nanosheets. Interestingly, the introduction of PDA not only improves the yield and the crystal regularity of MnO2 nanosheets, but also enables the strength of CF to be maintained. The interlayer shear strength and interfacial shear strength of the modified CF/PA6 composites are increased by 19.45% and 37.45%, respectively, compared with those of the desized CF/PA6 composites. Meanwhile, the introduction of MnO2 nanosheets also improves the EMI shielding performance of the composites to commercial standards. The interfacial enhancement and EMI shielding mechanisms of the composites are elaborated, which enriches the theoretical system of CF composites for multifunctional applications.