Mechanical performance of a CFRP composite reinforced via gelatin-CNTs: A study on fiber interfacial enhancement and matrix enhancement

Abstract This study investigates the effect of a bio-surfactant gelatin-modified carbon nanotubes (g-CNTs) on the fiber interfacial property and matrix performance of carbon fiber-reinforced polymer (CFRP) composite. Transverse fiber bundle test (TFBT) and in situ three-point bending test were conducted to analyze the fiber/matrix interfacial normal strength (IFNS) and bulk mechanical performance of the CNTs–CFRP composite. The results showed that g-CNTs have superb affinity and uniformity wrapping on the surface of carbon fiber via 2 min electrophoretic deposition (EPD) under a concentration of 0.1 mg/mL and a voltage strength of 10 V/cm, resulting in an increase of 40.3% of IFNS and 22.1%/25.3% of flexural strength/modulus of CFRP composites. Meanwhile, g-CNTs can also evenly distribute in the resin matrix with an improvement of 12.6% of IFNS and 20.3%/11.4% of flexural strength/modulus of CFRP composites under 0.1 wt% loading. This study provides a mechanism basis for the subsequent introduction of g-CNTs for the development of advanced CNT-reinforced CFRP composite.