Towards the development of self-healing carbon/epoxy composites with improved potential provided by efficient encapsulation of healing agents in core-shell nanofibers

Abstract

A self-healing carbon/epoxy composite was fabricated with the incorporation of healing agent loaded core-shell nanofibers between carbon fiber fabric layers. The healing agents, consisting of two components, a low viscosity epoxy resin and its amine-based curing agent, were encapsulated in Styrene acrylonitrile (SAN) nanofibers via a coaxial electrospinning method. Transmission electron microscope (TEM), Fourier Transform Infrared (FTIR), and thermogravimetric analysis (TGA) results confirmed the successful encapsulation of both epoxy and curing agent in SAN nanofiber shells. TGA and the extraction method confirmed a high encapsulation yield (90% for the epoxy resin and 97% for the curing agent). Mechanical studies of the hybrid composite showed that embedding the fabricated core-shell nanofibers did not lead to a reduction in the mechanical properties of host composite, which was corroborated with statistical analysis. Mechanical evaluations and curing behavior studies both showed that incorporation of the aforementioned nanofibers between carbon layers can imbue the conventional carbon/epoxy composite with a self-healing ability, allowing it to repair itself to restore its mechanical properties for up to three cycles at room temperature in absent of any external driving force.