Evaluation of the impact of oleic acid-capped Al ₂ O ₃ nanoparticles on the tribological performance of conventional lube oil

Purpose This study aims to evaluate the influence of oleic acid (OA)-capped Al 2 O 3 nanoparticles on the tribological performance of conventional lube oil. The goal is to determine the optimal nanoparticle concentration that enhances lubricant efficiency by reducing friction and wear. Design/methodology/approach The research involved preparing nanolubricants with four different concentrations of Al 2 O 3 nanoparticles: 0.05, 0.1, 0.25 and 0.5 wt.%. Tribological performance was assessed using a four-ball tribotester, which measured the coefficient of friction (COF) and wear scar diameter (WSD) under standardized testing conditions. Findings The experimental results revealed that the nanolubricant containing 0.1 wt.% OA-Al 2 O 3 nanoparticles exhibited the most significant improvement in tribological performance. This formulation achieved a 38.84% reduction in COF and a 23.87% reduction in WSD compared to the base lubricant. These findings demonstrate the effectiveness of incorporating OA-capped Al 2 O 3 nanoparticles in reducing friction and wear, thereby enhancing the overall performance of conventional lubricants. Originality/value This study demonstrates the benefits of OA-capped Al 2 O 3 nanoparticles in lubricants, including a 38.84% reduction in COF and a 23.87% reduction in WSD. By systematically analyzing different nanoparticle concentrations, it identified that 0.1% by weight of nanoparticles is the most effective formulation for reducing friction and wear. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0236/