Thermophysical and Electrical Properties of MnO2 and TiO2 Nanotubes Dispersed Transformer Oil

Semiconducting metal oxide nanotubes were dispersed in transformer oil to synthesize highly thermal conducting and electrically insulating nano-oils. Metal oxide nanotubes viz. one-dimensional MnO2 nanotubes (MNTs) and TiO2 nanotubes (TNTs) were prepared by simple hydrothermal method. The phase purity of metal oxide nanotubes was characterized by X-ray diffractograms (XRD). Field emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) were performed to access the morphology of nanomaterials. Vibrational properties of MnO2 and TiO2 nanotubes were analyzed using Raman spectroscopy. The nanomaterials were rendered hydrophobic for proper dispersion in transformer oil. Thermal conductivity behavior of MNTs and TNTs dispersed transformer oil was studied with varied volume fractions and temperatures. Viscosity measurements with temperature were investigated to understand the dispersion phenomena. Further, dielectric strength and electrical conductivity measurements were carried out to discuss the electrical insulation properties of nano-oils.