Solvothermal synthesis and electrical conductivity model for the zinc oxide-insulated oil nanofluid

A new kind of nanofluid, ZnO-insulated oil nanofluid was prepared from ZnO nanoparticles synthesized by solvothermal method. Electrical property measurement shows that the electrical conductivity increases by 973 times after adding 0.75% volumetric fraction of ZnO nanoparticles into the insulated oil. A linear dependence of the electrical conductivity on the volumetric fraction has been observed, while the temperature dependence of the electrical conductivity reveals a nonlinear relationship. An electrical conductivity model is established for the nanofluid by considering both the Brownian motion and electrophoresis of the ZnO nanoparticles.

► Stable ZnO-insulated oil nanofluid was successfully prepared.
► The electrical conductivity of the ZnO nanofluid is investigated.
► A new model is established to explain the electrical properties of the nanofluid.