Dielectric strength and stability of natural ester oil based TiO2 nanofluids

• Published in: Journal of molecular liquids 2020-10, Vol.316, p.113901, Article 113901
• Main Authors: Koutras, Konstantinos N., Naxakis, Ioannis A., Antonelou, Aspasia E., Charalampakos, Vasilios P., Pyrgioti, Eleftheria C., Yannopoulos, Spyros N.
• Format: Article
• Language: English
• Subjects: AC breakdown voltage; Lightning impulse; Stability; TiO2 nanoparticles; Transformer oil
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.113901

The synthesis of insulating nanofluids by integration of nanoparticles in insulating oils has been employed over the last two decades by many researchers in an effort to improve both the dielectric strength and the thermal conductivity of dielectric liquids. In this paper, nanofluids with different volume concentrations of the nanoparticles were prepared by integration of semi-conductive TiO2 nanoparticles into natural ester oil. Ultra-sonication and magnetic stirring were used for preparing homogeneous dispersions. AC, Lightning Impulse Breakdown Voltage and Partial Discharge Inception Voltage were measured and compared to the corresponding values of the base oil. Furthermore, the stability of the dispersions was studied ex situ by Transmission Electron Microscopy and in situ by Dynamic Light Scattering. Experimental results reveal the optimal TiO2 nanoparticles' concentration in terms of breakdown voltage maximization, and future extensions of the current research are provided. •AC BDV of nanofluids is enhanced with highest maximization by 22.4%.•NF2 and NF3 present enhanced LI BDV with the highest maximization being 12.9%.•Paper impregnated to NF3 shows the greatest resistance to appearance of PD by 40%.•DLS shows agglomerates present an abrupt increase against time.