Preparation of silver-plated carbon nanotubes/carbon fiber hybrid fibers by combining freeze-drying deposition with a sizing process to enhance the mechanical properties of carbon fiber composites

A facile method to prepare silver-plated carbon nanotubes (CNTs)/carbon fiber (CF) hybrid fibers that shows significant mechanical properties enhancement functions was proposed. In this method, abundant CNTs were evenly deposited on the CF surface by freeze-drying deposition and tightly attached to the CF surface by the following sizing process. The Ag@CNTs network on the CF surface significantly enhanced the wettability of the hybrid fibers and increased the interfacial mechanical interlocking between the fiber and matrix, thus significantly enhancing the properties of the CFRP composites. Compared with the untreated CF/EP composites, the interlaminar shear strength (ILSS), flexural strength, impact strength, thermal conductivity, and the electrical conductivity in the thickness direction of the C-CF-Ag@CNTs/EP composites were increased by 54.7%, 62.7%, 107.2%, 37.5% and 385.8%, respectively. Such a simple and effective method of preparing silver-plated CNTs/CF hybrid fibers provides great potential in industrial applications.