Preparation and characterization of highly conductive polyurethane composites containing graphene and gold nanoparticles

Two series of gold nanoparticles/graphene/polyurethane composite films were prepared using a solution mixing method. The first series was of constant loading of graphene/polyurethane with varying levels of gold nanoparticles (AuNPs), while the second was of varying graphene content with constant loading of AuNPs. The electrical conductivity of the AuNPs/graphene/polyurethane composites was determined using the two-point probe method. For the first series, a maximum conductivity of 0.424 S cm−1 was achieved with a 5% AuNPs/5% graphene/polyurethane composite, and for the second, a maximum conductivity of 1.388 S cm−1 was achieved with a 5% AuNPs/15% graphene/polyurethane composite. The composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and tensile testing methods. Tensile strengths and thermogravimetric analyses showed, respectively, acceptable mechanical properties and thermal stability of the parent polyurethanes. Furthermore, cytotoxicity assay tests evidenced that AuNPs/graphene/polyurethane composites were not cytotoxic to living cells in vitro and, consequently, potentially useful in biomedical applications.