Extensive examination of sonication duration impact on stability of Al2O3-Polyol ester nanolubricant

Abstract The sonication technique is one of the effective methods to stabilize nanolubricants. This paper aims to elaborate on the sonication duration's impact on the stability of Al2O3-Polyol ester nanolubricants. A two-step method has been performed to prepare nanolubricants. Each sample consisted of a nanoparticle mixed with POE using a magnetic stirrer without surfactant for 30 min. All samples had the same volume concentration, namely 0.02 vol% but received different interlude sonication duration treatments for 0, 40, 60, 80, 100, and 120 min. FESEM with Energy Dispersive X-Ray was used to characterize the Al2O3 nanoparticle sample's morphology and element analysis. UV Visible and absolute zeta potential were used to determine Al2O3-POE nanolubricants stability. The findings show that the most optimal sonication impact in this study is 80-min sonication. It proofed by the highest absorbance ratio among other samples, which is 0.411, the lowest drop absorbance value, which is 58.9%, and and with a zeta potential value of 45 mV. The rheological behavior analysis shows that Al2O3-POE nanolubricants show Newtonian behavior.