Electrophoretic deposition of “ PEDOT / GO ‐ CF ” nanostructures for improving mechanical properties and in‐situ damage detection of unidirectional carbon fiber fabric reinforced composites

Abstract Carbon fiber unidirectional fabric composites are used in a variety of applications due to their excellent mechanical properties. However, detecting internal damage before material failure remains a challenge. In this study, poly(3,4‐ethylenedioxythiophene) (PEDOT)/graphene oxide (GO)‐carbon fibers (CF) nanostructures have been constructed on the surface of CF using electrophoretic deposition (EPD) of poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) onto GO coated CF for real‐time damage detection of the unidirectional CF fabric composite. PEDOT/GO increased the chemical reactivity of CF and promoted mechanical interlocking between the fibers and resin. Compared with the untreated CF composites, the interlaminar shear (ILSS) of CF‐GP/EP increased by 21.46%, while the flexural strength and flexural modulus increased by 24.81% and 38.8%, respectively. Furthermore, PEDOT/GO‐CF nanostructures bring more interconnected conductive paths that could assist in distinguishing the microcracks in the unidirectional CF fabric‐enhanced composites by electrical signals, thereby reducing property damage before material failure. This study provides a promising potential for simultaneously enhancing the sensitivity of damage detection and the mechanical properties of carbon fiber composites. Highlights Nanostructures are formed on CFs through electrophoretic deposition of PEDOT. The damage detection abilities of different CF fabrics were compared. The prepared CF composites have excellent mechanical properties. The prepared CF composites can detect damage before they break.