Effect of ionic liquid on graphene decorated with copper nanostructure dispersion towards silicon/graphene/copper composites with enhanced thermal, electrical and antimicrobial properties

Graphene decorated with cooper nanostructures were prepared with and without ionic liquid (IL) using different milling times. The obtained samples were characterized by Raman, X-ray diffraction (XRD) and transmission electron microscopy (TEM), to analyze the effect of the grinding time on the copper particles adhesion to the graphene sheets. Composites of silicon with two contents of G/Cu, at two weight ratios, nanostructures were prepared and the crosslinking characteristics were analyzed by a rubber process analyzer. The thermal conductivity, electrical resistivity and antimicrobial characteristics against E. coli and S. aureus for these silicon/G/Cu composites were determined. It was found that the use of IL enhances the G/Cu nanostructures dispersion into the silicon polymer matrix with a noticeable improvement in thermal conductivity of 1.12 W/mK for a 7 wt% of G/Cu, a volume electrical resistivity of 4.1 × 10 10 Ω cm with 7 wt% of G/Cu nanoparticles and antimicrobial response of 4.21 ± 0.11 to E. coli and 5.33 ± 0.11 to S. aureus with 7% of G/Cu nanoparticles. It was determined that π–π interactions between graphene and aromatic molecule of IL may be influencing the observed improvement in G/Cu dispersion and final composite performance. The novelty of this work is the use of IL to improve the G/Cu NPs dispersion into the silicon polymer matrix. This silicon/G/Cu composite could be an option to prepare medical devices for electrotherapy or face protection against COVID-19 or other silicon-based devices for medical applications. Graphic abstract