Electrophysical Properties of Nanooil Under Different Preparation Conditions

The breakdown voltage of transformer oil containing nanoadditives — carbon nanotubes or titanium dioxide — has been experimentally determined. The breakdown voltage of nanooil based on carbon nanotubes turned out to be significantly lower than that of pure oil. At low concentrations, the breakdown voltage values approximately correspond to those of pure liquid, but with increasing concentration, the it drops catastrophically. It has been shown that the technology of nanofluid preparation greatly affects its breakdown voltage. A different result was obtained for the case of TiO2 nanoparticles with additives of surfactants (oleic acid and sodium dodecyl sulfate). It has been confirmed that the breakdown voltage of nanooil increases by 20–30% with increasing nanoadditives, but with an increase in concentration above 0.4 g/L, it begins to drop to values below the strength of the base liquid. Measurements of the electrical conductivity of nanofluids show that the specific resistance of oil with nanotubes decreases with increasing concentration, while that of oil with titanium dioxide increases. This allows the use of nanooil in industry not only for heat-dissipating devices, but also for high-voltage devices.