Construction of cellulose nanofiber/carbon nanotube synergistic network on carbon fiber surface to enhance mechanical properties and thermal conductivity of composites

Drawing inspiration from the robustness and resilience of spider silk, this study harnessed a combination of polydopamine (PDA), cellulose nanofibers (CNFs), polyvinyl alcohol (PVA), and aminated carbon nanotubes (CNTs) to create a synergistic network through hydrogen and covalent bonding on the surface of carbon fibers (CFs). This strategy significantly bolstered the interfacial properties of the resulting composites. The enhancements in flexural strength, flexural modulus, interlaminar shear strength (ILSS), tensile strength, and interfacial shear strength (IFSS) were measured at 47.8 %, 75.2 %, 54.3 %, 55.6 %, and 51.8 %, respectively. These improvements are attributed to the formation of robust covalent and hydrogen bonds among PDA, CNF, PVA, and aminated CNTs. Furthermore, the thermal conductivity of the CF composites saw a 59.7 % increase, owing to the CNFs and CNTs. These nanofillers are instrumental in forming an efficient thermal conductivity pathway within the resin matrix, which contributes to the improved thermal conductivity. This study introduces a straightforward, eco-friendly, and innovative approach for the production of high-performance CF composites.