Effect of particle concentration on lubrication performance of cellulose nanocrystalline (CNC) water-based lubricants: mixed lubrication regime

Industrial lubricants enhance the performance of machinery by reducing the generated wear and friction among mechanical components. In many of these applications, lubrication under mixed regime is more preferred than boundary regime, to decrease the friction among solid bodies. Due to the ecological and health hazards of oil-based lubricants, developing eco-friendly lubricants is crucial to protect our environment. High thermal stability, non-toxicity and biodegradability of cellulose nanocrystals (CNCs) are favorable features to create green lubricants. In this study, using microstructural, tribological and rheological characterization methods, the effect of nanoparticles concentration on lubrication performance of CNC aqueous suspensions was investigated. It was found that under the mixed mode of lubrication, there exists an optimum CNC concentration regime (1–2 wt%), where the corresponding friction coefficient and wear reach their minimum values.