Self-healing study of impact damage in carbon fiber composites based on electrostatically spun polyacrylonitrile core-shell nanofibers

Carbon fiber composites containing core-shell nanofibers (PAN@CFRP) were prepared by incorporating electrospun polyacrylonitrile core-shell nanofibers between the layers of carbon fiber reinforced polymer composites and the damage healing ability was assessed after being subjected to low-velocity impact. Three impact energies (25.2, 33.5, and 41.9 J) were selected for the study. The incorporation of core-shell nanofibers improved the impact resistance of the composites compared with pure carbon fiber composites (CFRP); the PAN@CFRP specimens were found to have a smaller damage area and a lower damage level by visual observation and optical microscopy. The healing efficiency was 66.3%, 43.5%, and 8.83% for the residual compressive strength and was normalized to the residual compressive strength when the impact energy was less than 37.5 J. The healed materials were found to recover more than 80% of their undamaged residual compressive strength when the impact energy was less than 37.5 J. Therefore, the core-shell nanofiber healing system can, to a certain extent, solve the problems caused by the incorporation of other healing systems, and can largely recover the impact damage encountered in practical applications.