The area of nanotribology has advanced greatly in the past 17 years with the introduction of scanned probe microscopies for the characterization of surface properties. The ability to probe the details of structure, friction and adhesion on a local atomic/molecular scale affords a definitive approach for understanding the mechanisms of wear at the most fundamental levels. Muscovite mica, a layered alumino-silicate in the form of KAl2(Si3AlO10)(OH)2, has been a suitable standard for the investigation of the atomic scale relationship between friction, adhesion and wear by atomic force microscopy (AFM) due to the ability to readily generate large domains of atomically smooth surface. To date the majority of surface wear studies have focused on the evaluation of surface structure before and after wear. Here we describe studies that have focused on the nanoscale studies of wear in situ. We will first begin with a description of the structure and chemistry of the mica surface. We will then focus on the scanned probe methodologies employed in the investigation of nanotribological properties of mica surfaces, including a brief description of the operating principles of the atomic force microscope (AFM), lateral force (or friction) measurements by AFM, as well as adhesion measurements. Moreover, as one wishes often to quantify such details we will also describe methodologies employed to calibrate the signals retrieved from such experiments and then provide a brief description of a standardized approach for the measurement of wear at surfaces, whereby the details of the tip contact area will be explicitly taken into consideration when evaluating the number of scans needed to induce wear at an interface. After describing these approaches, we will then focus on the wear of the mica surface, including the impact of water, and functionalization of the mica surface with alkylsilanes.
Encyclopedia of Nanoscience and Nanotechnology
adhesion, AFM, force microscopy, friction, nanotribology
Charge Nucleation and Wear on Mica Surfaces, Encyclopedia of Nanoscience and Nanotechnology
(Accessed June 4, 2023)