Multiscale Structure Construction by Layer-by-Layer Self-Assembly to Modify the Carbon Fiber Surface

Graphene oxide/silica (GO/SiO2) multilayers could be successfully deposited onto a carbon fiber (CF) surface via a convenient and efficient layer-by-layer (LbL) self-assembly approach. It is possible to assemble GO with negative charge and SiO2 with positive charge on the CF surface by virtue of electrostatic interactions, as well as to systematically characterize CF surface microstructures. Scanning electron microscopy (SEM) detects the compact and uniform adherence of GO/SiO2 multilayers to the surfaces of CFs. The coverage contributes to an obvious improvement on the surface energy and roughness of fibers; thus, the wettability exhibited by the CF surface is enhanced. In addition, following GO/SiO2 LbL assembly, the tensile strength exhibited by single fibers increases in the range 2.99–3.21 GPa. As discovered by our work, this kind of approach serves as a promising surface modification approach to optimize the wettability as well as the mechanical property owned by CFs.