Dielectric strength and stability of natural ester oil based TiO2 nanofluids

The synthesis of insulating nanofluids by integration of nanoparticles in insulating oils has been employed over the last two decades by many researchers in an effort to improve both the dielectric strength and the thermal conductivity of dielectric liquids. In this paper, nanofluids with different volume concentrations of the nanoparticles were prepared by integration of semi-conductive TiO2 nanoparticles into natural ester oil. Ultra-sonication and magnetic stirring were used for preparing homogeneous dispersions. AC, Lightning Impulse Breakdown Voltage and Partial Discharge Inception Voltage were measured and compared to the corresponding values of the base oil. Furthermore, the stability of the dispersions was studied ex situ by Transmission Electron Microscopy and in situ by Dynamic Light Scattering. Experimental results reveal the optimal TiO2 nanoparticles' concentration in terms of breakdown voltage maximization, and future extensions of the current research are provided.