2D mica as a new additive for nanolubricants with high tribological performance

This article presents 2D mica nanoplatelets as a novel additive to produce a stable engine lubricant. The planar structure and excellent mechanical properties of 2D mica contribute significantly to the improvements in tribological performance when evaluated under pure sliding and rolling/sliding contact configurations. The wear rate is reduced by 72 %, and the coefficient of friction (COF) decreases by 28 % when 2D mica is added to engine oil under pure sliding conditions. No tribological improvement was observed under rolling/sliding conditions. Our results also showed that nanosheet loading plays a significant role in nanolubricant performance, where 0.2 wt% is the optimum. These findings demonstrate superior performance to other 2D material nanoadditives and indicate the potential for commercial applications of 2D mica-based nanolubricants

Nanoscale insights into the structure of solution-processed graphene by x-ray scattering

Chemical exfoliation is an attractive approach for the synthesis of graphene due to its low cost and simplicity. However, challenges still remain in the characterization of solution-processed graphene, in particular with atomic resolution. Through this work we demonstrate the x-ray pair distribution function as a novel approach to study solution-processed graphene or other 2D materials with atomic resolution, directly in solution, produced by liquid-phase and electrochemical exfoliations. The results show the disappearance of long-range atomic correlations, in both cases, confirming the production of single and few-layer graphene. In addition, a considerable ring distortion has been observed as compared to graphite, irrespective of the solvent used: the normal surface angle to the sheet of the powder sample should be less than 6°, compatible with ripples formation observed in suspended graphene. We attribute this effect to the interaction of solvent molecules with the graphene nanosheets