Sliding Friction Measurements of Molecularly Thin Ethanol and Pentanol Films: How Friction and Spreading Impact Lubricity

摘要

We describe herein how a quartz crystal microbalance (QCM) can be used to measure wetting behavior and sliding friction levels of adsorbed films and a brief summary of the status of the fundamental energy dissipative mechanisms that give rise to friction in these systems. The relation between sliding friction values, diffusion coefficients, and film lubricity is next described. Finally, as a specific case example, QCM measurements of the uptake and sliding friction levels of adsorbed ethanol, trifluoroethanol (TFE) and pentanol films on silicon, aluminum and perfluorodecyl-trichlorosilane (PFTS) treated substrates are reported and analyzed. These systems are of interest to the silicon microelectromechanical systems (MEMS) community, whose progress has been limited by tribological issues. Keywords Friction - Diffusion - SAM - QCM - Alcohol - MEMS