Investigation of Rheological and Wettability Behavior of Hex-BN Nanofluids

摘要

Conservation of energy has become a need of the hour, as a substantial amount of energy is wasted in maintaining machines. The rheological and wettability behavior of lubricants plays an instrumental role in enhancing machine life. Nano additives have shown encouraging results in this regard, though there are so many challenges that need to be addressed. The flow behavior of lubricants largely depends on the rheological and wetting behavior of lubricants. The rheological properties include shear stress, shear rate, viscosity, and viscoelastic behavior of oils. Similarly, the wettability properties include the contact angle of the oils. Both of these properties influence the tribological performance in the end. In the present study, the rheological and wettability behavior of hexagonal boron nitride (Hex-BN) nanofluids is presented. The study has been carried out on two commercially available blended synthetic engine oils of the same grades. The oils are blended with 0.1% and 0.2% weight by weight of well-dispersed Hex-BN nanoparticles. The study reveals that tested Hex-BN nanofluids behaved as non-Newtonian lubricants with shear thinning behavior at all tested temperatures and exhibited viscoelastic behavior at lower shear rates. On blending oils with 0.2% Hex-BN, contact angle has shown increment across the board for all surfaces. It indicates that Hex-BN binds better with the lubricants' molecules, hence increasing the force of cohesion. Furthermore, it is a sign of better dispersion of Hex-BN nanoparticles in the given lubricants.