As a kind of new material, ionic liquids (ILs) are considered a new type of lubricant for micro/nanoelectromechanical system?(M/NEMS) due to their excellent thermal and electrical conductivity. However, so far, only a few reports have investigated the?friction and wear of thin films of these materials at the micro scale. Evaluating the nanoscale tribological performance of ILs?when applied as films of a few nanometers thickness on a substrate is a critical step for their application inM/NEMS devices. To?achieve this purpose, IL thin filmswith four kinds of anions were synthesized and prepared on single-crystal silicon wafers by the?dip-coatingmethod. Film thicknesswas determined by the ellipsometric method. Their surfacemorphologieswere observed by?meansof atomic forcemicroscopy (AFM).Thenanoandmicro tribologicalpropertiesof the ILfilmswereinvestigatedbya friction?forcemicroscope (FFM)with a spherical probe and a UMT-2MT tribotester, respectively. The corresponding morphologies of the?wear tracks of the IL films were examined using a three-dimensional non-contact interferometric microscope. The impact of?temperature on the adhesion behavior was studied, aswell as the effect of sliding frequency and load on the friction coefficient,?load bearing capacity and anti-wear durability. It was found that friction, adhesion and durability of IL films were strongly?dependent on their anionicmolecular structures, wettability and ambient environment.?
Yufei Mo,Fuchuan Huang,Fei Zhao.
Surface and Interface Analysis