Graphene–Ionic Liquid Based Hybrid Nanomaterials as Novel Lubricant for Low Friction and Wear

Abstract

Hybrid nanomaterials offer potential scope for an increasing number of novel applications when engineered to deliver usefully functional properties. Recent advancements in the design of new material products that result from interactions among different compositions at the nanoscale and microscale has led to innovative ways to fabricate and process hybrids with altered structural physicochemical properties. An example is the development of novel "lubricants" that make use of ionic liquids (ILs) and their ability to induce exploitable molecular assemblies at the IL-graphene interface. In the present study, we report the potential of graphene-IL hybrid nanomaterials for engineering applications with a focus on "lubricant" properties to reduce frictional forces to enhance tribological performance. The present contribution outlines the wear and tribological properties (friction and lubrication) of a highly viscous IL [BMIM][I] and its comparison with its nanohybrid material counterpart. Detailed structural-microstructural investigations of the nanohybrid materials were performed using X-ray diffraction and microscopic techniques employing scanning electron (SEM), transmission electron (TEM), and high resolution transmission electron (HRTEM) microscopies. A comparative study of the morphology of friction track and wear behavior was assessed by SEM and TEM. These characteristic properties within and outside the friction track were further correlated with physical and chemical interactions obtained by contact angle measurements and Raman spectroscopy and energy dispersive analysis by X-ray (EDAX).