Breakdown Voltage of Natural Ester-Based Nanofluid: A comparison between anatase-TiO2 and rutile-TiO2 nanoparticles

Nanoparticles have been found to improve the dielectric properties of insulation fluids. Existing literature has shown that the improvement given by these nanoparticles is dependent on the different properties of the nanoparticles, including the type and the amount of nanoparticles used. This work presents a study on the effects of TiO2 nanoparticles on the breakdown strength of natural ester oil. A uniform field AC breakdown voltage test was used to compare anatase and rutile TiO2 polymorphs' effects on a natural ester liquid. The nanofluid containing anatase-TiO2 was found to provide the highest breakdown voltage for different concentrations. A maximum improvement of 85% was obtained with a sample containing 0.05 vol% of anatase-TiO2. Rutile-TiO2 had a 61% improvement at the same volume concentration. The improvement is attributed to the electron-trapping ability of the nanoparticles. The possible related electron transfer mechanisms are discussed.