Direct Ink Writing of Graphene Oxide Reinforced PDMS Matrix Composites for Improved Mechanical Properties

Recently, PDMS has been widely used because of its outstanding properties, such as its biocompatibility, moldability, and Mechanical Flexibility. However, the low mechanical strength hinders its ability for further applications. The Addition of graphene oxide (GO) into Polydimethylsiloxane (PDMS) matrices as a reinforcement is a reasonably simple way to improve its mechanical properties. Direct ink writing (DIW) is an ideal method for printing viscous materials which provides useful advantages for fabrication, such as higher design freedom, as well as having no requirement for a castable mold, compared to conventional PDMS processing methods. Herein, we demonstrate the DIW 3D printing of GO reinforced PDMS matrix composites. PDMS SE 1700 and Sylgard 184 were mixed in 4:1 and 7:3 ratios as matrix materials with controlled rheological properties. GO, synthesized by modified Hummer’s method, was loaded into PDMS at various weight ratios (0.5%, 1%, 2%, 3% and 4%) to fabricate GO/PDMS composites. The GO dispersed uniformly throughout the PDMS matrix with no visible aggregation during the mixing and printing processes. Tensile tests were performed using 3D printed dog-bone shape GO/PDMS bars to evaluate the enhancement of the GO reinforcement. The results showed that the Young’s modulus of PDMS increased by 58.7% with 1% GO reinforcement.