Micro and nanoparticles blended sesame oil bio-lubricant: study of its tribological and rheological properties

Non-renewability, depleting resources and damage caused to the environment by mineral oil-based lubricants are the greatest concerns of this century. Recently, these issues have triggered a global trend to use vegetable oil-based lubricants in industries. Sesame oil (SESO) extracted from widely cultivated tropical crop - sesame (Sesamum indicum') possesses distinctive characteristics such as low pour point and reasonable oxidation stability. However, the poor tribological properties of SESO limit its application as an industrial grade lubricant. Further improvement of these properties can aid its use as potential bio-lubricant in industries. This work encompasses the blending of micro and nanoparticles in SESO with the aim of enhancing its tribological properties to suit many industrial purposes. The tribological properties of SESO with nanoparticles having morphology variation spherical-shaped titanium dioxide (TiO2) and rod-shaped zinc oxide (ZnO) are used. The significance of adding microparticles is also dealt with by using molybdenum disulphide (MoS2). Tribological properties and stability of the above-formulated lubricants with and without the addition of surfactant to particles are studied. The rheological properties of the oil blends are examined using a rheometer. Studies indicate that rod-shaped ZnO blended SESO reduces the coefficient of friction and wear scar diameter by 24.04 and 13.74%, respectively.