A method for reliable measurement of relative frictional properties of different self-assembled monolayers using frictional force microscopy

A practical method of preparing silica surfaces coated with spatially segre gated silane amphiphiles for the purpose of accurately comparing their fric tional properties is discussed. The method uses a UV/ozone photochemical pr ocess that utilizes spatially selective decomposition and deposition of amp hiphiles. By using a scanning electron microscope (SEM) grid, selected area s of a self-assembled monolayer (SAM) are either exposed to or protected fr om the degradation process. The process shows no detrimental effect to the silica surface, nor does it affect the properties of the masked monolayer r emaining after degradation. Contact angle goniometry and friction force mea surements of several organosilane SAMs demonstrate the effectiveness of the method. (C) 2001 Elsevier Science B.V. All rights reserved.