Enhancing dielectric performance and sustainability: TiO ₂‐infused Eruca sativa oil as a high‐efficiency insulating fluid for power transformers

Abstract This study explores the impact of titanium dioxide (TiO₂) nanotubes on the physical and dielectric properties of Eruca Sativa (ES) oil for potential use in power transformers. With growing demand for sustainable alternatives to mineral oils, vegetable oils offer benefits such as biodegradability, high flash points, and strong dielectric performance. ES oil, extracted from Arugula seeds and widely available in Asia, remains underexplored for such applications. In this work, ES oil‐based nanofluids (NFs) were developed by dispersing TiO₂ nanotubes at 0.01 and 0.1 g/L concentrations using ultrasonication. Physical properties including viscosity, moisture content, specific gravity, acidity, flash point, and pour point were measured following IEC/ISO standards. Dielectric strength was assessed via AC breakdown voltage tests using mushroom electrodes, considering the effects of temperature and humidity. The NF with 0.01 g/L TiO₂ showed the most favorable results, enhancing AC breakdown voltage by 33% compared to pure ES oil. It also demonstrated a 5.14% increase in viscosity and a significant drop in pour point, indicating better low‐temperature performance. A cost–benefit analysis revealed a positive ratio of +0.08, suggesting economic viability. ES oil‐based nanofluids, especially at lower TiO₂ concentrations, provide a sustainable and efficient alternative to conventional mineral oil for transformer insulation.