Fabrication of Graphene-Reinforced Nanocomposites with Improved Fracture Toughness in Net Shape for Complex 3D Structures via Digital Light Processing

Abstract

A solvent-free method to fabricate graphene-reinforced nanocomposites in net shape via digital light processing (DLP) 3D printing has been developed in this work. The effect of graphene nanofillers on resin viscosity and wettability for various printing parameters has been examined, with a systematic characterization of the mechanical and thermomechanical properties. With the addition of 0.5 wt.% graphene nanoplatelets in the resin, the flexural modulus and fracture toughness have been improved by 14% and 28% from neat resin, respectively. Thermomechanical properties of graphene-reinforced nanocomposites were also enhanced compared with the neat resin, without scarification in their printability. The feasibility of utilizing the DLP method to fabricate a fracture toughness specimen (KIC test) without complex skill-dependent notch preparation steps was explored, with different notch tip angles printed for net-shaped specimens. This provided a simple and versatile way to perform a quick examination of reinforcing efficiency from nanofillers at very low cost with high resolution and reproducibility. To demonstrate the suitability of current resins for complexly shaped structures, a gyroid scaffold for tissue engineering applications based on current graphene nanocomposite resins has been successfully fabricated via DLP, showing the great potential of current photocurable resins for applications in various fields such as tissue engineering or personalized medical devices without the cost barriers of traditional methods.