Exploring SiO2, TiO2, and ZnO nanoparticles in coconut oil and mineral oil under changing environmental conditions

In this study, three nanoparticle (NP) categories (SiO2, TiO2, ZnO) were used to prepare nanofluids with RBD coconut oil (CO) and mineral transformer oil (MO). The primary challenge lies in improving the electrical breakdown strength of vegetable oils, with a specific focus on coconut oil in this context. This enhancement is crucial to optimize the use of vegetable oils as liquid insulation. The selection of nano-additives plays a vital role in improving breakdown strength. Stability assessment led to investigating nanofluids with 0.1 wt% NPs of different types and 1.0 wt% SiO2 NP for endurance and electrical performance during four weeks of aging at 120 degrees C. It was found that SiO2 NP enhance AC breakdown voltage (AC BDV) in CO but fail to protect against aging, despite stable viscosity compared to MO. Fresh MO with SiO2 NPs shows no significant AC BDV improvement but preserves breakdown strength. ZnO NPs moderately impact both CO and MO, safeguarding only MO from aging. Unfortunately, TiO2 NPs offer no benefits for AC BDV or aging protection in either oil. Further, Weibull analysis showed aging decreased AC withstand voltage in CO, while most nanoparticles (excluding TiO2 NP) also reduced it. However, SiO2 NP at 0.1 wt% and 1.0 wt% in MO exhibited higher AC withstand voltage, particularly in aged samples. The same trend was observed with 0.1 wt% ZnO NP in MO.