Enhanced Dielectric and Mechanical Properties of Natural Rubber Composites Filled with Gold Nanoparticles

In this work, we present the novel robust material, modified natural rubber (NR) composites filled with gold nanoparticles (AuNPs). To investigate its outstanding properties, dielectric, electrical and mechanical properties of NR and modified NR composites filled with gold nanoparticles (AuNPs) were studied. The NR and all composite films were prepared by using solution casting method. The size of the synthetic AuNPs was analyzed by Transmission Electron Microscope (TEM) technique. The dispersion of AuNPs fillers within the NR matrix was investigated by scanning electron microscopy (SEM). Dielectric and electrical properties of NR composites were analyzed as function of filler concentration and frequency in a range of 100-105 Hz, observed with the LCR analyzer. Elastic modulus of all samples was evaluated by a strain gauge set up. It was found that the dielectric constant is inversely related to the frequency. Moreover, the dielectric constant and the electrical conductivity strongly increase in proportional to the AuNPs filler content. In comparison at AuNPs concentration of 0.0010% by weight, it was observed that the dielectric constant of NR composites is eight times larger than the pure NR, while the mechanical properties of the NR composites slightly increase in proportional to the AuNPs. As consequence, the interfacial surface area significantly affects the electrical and mechanical properties of those NR composites.