Structure, properties, and antibacterial behavior of nickel oxide reinforced natural rubber nanocomposites for flexible electronic applications

In this work, different contents of nickel oxide (NiO) nanoparticles were inserted into natural rubber (NR) using an industrial compounding technique to improve its process ability, mechanical, thermal stability, conductivity, dielectric constant, antibacterial and optical properties. The Fourier transform infrared spectra of composites showed the characteristic band of NiO at 495 cm(-1) indicating the presence of nanoparticles in NR. The insertion of NiO into rubber showed a decrease in bandgap energy than pure NR. The crystalline peaks of nanoparticles in the rubber matrix were confirmed through X-ray diffraction pattern. The nano size distribution and surface morphology from HR-TEM and FE-SEM showed that the nanoparticles were uniformly dispersed throughout the elastomer matrix. The glass transition temperature and thermal stability of the nanocomposites were significantly enhanced by the reinforcement of NiO into the NR matrix. The vulcanization time was greatly reduced with the use of filler, lowering the cost of manufacturing rubber products for the market. The AC conductivity, dielectric properties, tensile strength, tear, heat build-up, hardness, oil resistance, and antibacterial activities against Escherichia coli of nanocomposites were greatly increased, whereas the elongation-at-break, abrasion loss and resilience were decreased with the addition of nanoparticles to the natural rubber.