Improved interfacial mechanical strength and synergy in properties of nano-carbon black reinforced rubber composites containing functionalized graphite nanoplatelets

Due to increasing industrialization, the demand for energy continues to increase. In the present work, piezoelectric energy generation by a composite device was performed and demonstrated. Composites were prepared by solution mixing at room temperature silicone rubber (RTV-SR) precursor with fillers such as nanocarbon black (CB), functionalized graphite nanoplatelets (f-GNPs), and hybrids of CB and f-GNPs. GNPs as a graphite source were functionalized by oxidation using a modified Hummers' method and subsequently reduced. Fourier transform infrared spectroscopy (FT-IR) studied the carbon and oxygen-containing functional groups, and their binding energies were determined by X-ray photoelectron spectroscopy (XPS). A noticeable and prolonged synergistic effect was noticed in hybrid composites in which the mechanical properties conferred by hybrid nanofillers were greater than those conferred by single nanofillers. This synergetic effect was due to improved interconnectivity between CB particles and f-GNP particles. Compressive and tensile mechanical properties showed the compressive moduli and tensile strengths of hybrid filler-based composites were markedly higher than those of composites containing CB and f-GNPs as only nanofillers. Moreover, energy generation was lower for the CB-based electrode than for CB-f-GNP hybrid-based electrode composites.