Investigation on the electrical properties of palm oil and coconut oil based TiO₂ nanofluids

Abstract

This paper presents an examination on the electrical properties of Palm Oil (PO) and Coconut Oil (CO) under the presence of semi-conductive nanoparticle, Titanium (IV) Oxide (TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). The type of PO used in this study was Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein. TiO2 was dispersed into RBDPO and CO at volume concentrations ranging from 0.001% to 0.05%. The effect of surfactant, Cetrimonium Bromide (CTAB) was also examined and the morphology of RBDPO and CO based TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanofluid was observed through Transmission Electron Microscope (TEM). A number of measurements were carried out including the AC/lightning breakdown voltages, dielectric dissipation factor, relative permittivity and resistivity. Statistical analysis was carried out through Weibull distribution to determine the AC and lightning withstand voltages at 1% probability for RBDPO and CO. It is found that without CTAB, there are only slight improvements on the AC breakdown voltages of the RBDPO and CO with introduction of TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> but could decrease with presence of CTAB. The same pattern is found for lightning breakdown voltages of RBDPO and CO under non-uniform field where the highest percentages of increments decrease with introduction of CTAB while the effect is not apparent under quasi-uniform field. Significant effect of CTAB is found on the dielectric dissipation factors and resistivity of RBDPO and CO based TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanofluid while the relative permittivity are not affected. The statistical analyses reveal that RBDPO and CO experience apparent increments of the AC breakdown voltages at 1% probability after the introduction of TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> regardless with or without CTAB. The improvements done by TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> on the lightning breakdown voltages at 1% probability for all samples with CTAB under quasi-uniform field are more apparent than non-uniform field.