Thermophysical and corrosion inhibitor evaluation of graphene, aluminum nitride and barium titanate nanolubricants

A newly developed kind of fluid known as nanolubricant is produced by dispersing nanometer-sized materials in base oil. The main issue with nanolubricant is particle stability, which occurs when nanoparticles aggregate due to van der Waals forces. The aim of the study is to evaluate the performance of graphene (GR), aluminium nitride (AlN), and barium titanate (BTO) nanolubricants at 0.05 and 0.1 vol % concentrations. The stability was identified by using sedimentation photograph capturing method and zeta potential analysis, while KD2 Pro Analyzer was used to measure the thermal conductivity, and the effect of corrosion inhibitor evaluation was measured according to ASTM D130-19. The nanolubricants are prepared by two-step method and undergo ultrasonication process to ensure the nanoparticles are well dispersed in base oil. The results showed that nanolubricants containing 0.05 vol % nanoparticles are more stable than 0.1 vol % nanolubricants. Nanolubricants with 0.1 vol % showed signs of instability based on low zeta potential values. This is due to the fact that the higher the concentration of nanoparticles, the closer the nanoparticles are to one another. This increased van der Waals attraction and potentially causing nanoparticle agglomeration. Improvement in thermal conductivity was obtained with high volume concentration of GR, AlN and BTO nanoparticles. All nanolubricants achieved an ASTM Standard D130 classification of 1a based on the Copper Strip Corrosion Test Standard (slight tarnish, slight colour change). As a result, it was discovered that all prepared samples are effective anticorrosion lubricating oil additives.