Carbon nanomaterials enabled fiber sensors: A structure-oriented strategy for highly sensitive and versatile in situ monitoring of composite curing process

Abstract

Abstract Carbon nanomaterials (CNM) based technology has offered a variety of promising strategies for self-sensing and diagnosing functionalities in polymeric composites. In comparison with studies about detecting deformations and cracks, monitoring the manufacturing stage of composites using CNMs is rather limited. Based on continuous fabrication, we systematically investigated carbon nanotubes (CNTs) coated, graphene coated and carbon fiber sensors for monitoring complete molding process of composites through the real-time resistance change. Comparing to graphene-coated and carbon fibers with densely and continuously packed graphitic structures, the CNT fiber sensor with entangled and loosely packed porous network shows far superior performance for sensing different processing stages of composites, including resin infusion, gelation and curing. The resistance decay of the CNT sensor agrees well with curing kinetics measured by differential scanning calorimetry. Versatile capabilities of the CNT sensor were further explored for identifying various flowing defects such as dry spots and partially infiltrated areas.