Layer-by-layer assembly of biomimetic fish scale structure on carbon fiber surfaces to improve thermal conductivity and mechanical properties of composites

Prompted by the excellent properties of biomimetic fish scale hierarchy, the layer-by-layer (LbL) assembly methodology was adopted in this paper to generate the graphene oxide (GO), polyetheramine (PEA), and carbon nanotubes (CNTs) on the surface of carbon fibers (CFs), which leads to a new interface phase through the combination of alternately-arranged soft and hard inorganic nanoparticles and organic matrix. After two cycles of GO/PEA/CNT assembly conducted on the fiber surface, the thermal conductivity of the composite was improved by 51.5%. Besides, the interlayer shear strength, flexural strength, and flexural modulus increased by 52.2%, 33.3%, and 60.1%, respectively, which is attributed to the π-π interaction and π-π stacking between GO and CNTs, as well as to the synergistic interaction of hydrogen bonding and covalent bonding between GO/PEA/CNT. This study contributes a promising route to the production of biomimetic composites with high strength and excellent thermal conductivity.