Enhancing interfacial adhesion in carbon fiber‐reinforced composites through polydopamine‐assisted nanomaterial coatings

Abstract This study explores the surface modification of carbon fiber (CF) with multi‐walled carbon nanotubes, graphene, and zinc oxide nanoparticles to improve interfacial adhesion in carbon fiber‐reinforced composites. A polydopamine (PDA) layer was used as a coupling agent to enhance the deposition and uniformity of the nanomaterial coatings on CF. The novelty lies in using PDA, which mimics mussel adhesive proteins, offering robust adhesion due to its amine and catechol functional groups. Elemental mapping through energy dispersive x‐ray spectroscopy, along with Fourier transform infrared (FTIR) and x‐ray diffraction analyses, confirmed the successful nanomaterial deposition while preserving the CF's graphitic structure. Nanoparticle structures at the nano‐level were examined under a transmission electron microscope. Contact angle measurements showed improved wettability, decreasing from 85.9° to 52.8°, and increasing surface energy from 5.10 to 44.1 J/m 2 , indicating better adhesion potential. The modified CF surface demonstrated improved interfacial bonding between the matrix and CF making them promising candidates for applications in hydrogen storage systems and energy storage devices, such as structural supercapacitors and batteries. Highlights Surface modification of carbon fibers to enhance interfacial properties. Nanomaterials were grown in a two‐step process on catalyst‐pretreated carbon fibers using dip coating. Uniform nanomaterial coating on carbon fibers confirmed by field emission scanning electron microscope analysis. Increased functionality of carbon fibers demonstrated by FTIR spectra. Improved wettability and adhesion confirmed by contact angle and surface energy measurements.