Change of Self-Organized 2-Dimensional Structure and Frictional Property of Alkyl-Substituted Phthalocyanines Depending on Alkyl Chain Length

Abstract

The alkyl-substituted phtlialocyanmes physisorbed on each substrate with their molecular planes parallel to the substrate surfaces. Therefore, we considered that these molecules used as one of the ideal models for monolayer lubricants. In this study, we attempt to clarify the relationship between the surface adsorbed structure and frictional properties. We focus on phthalocyanine derivatives as an example of lubricant molecules. Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) were used for the characterization of the adsorbed structure of molecules, and the friction force measurement, respectively. Considering the interaction between molecules and substrate, and the intermolecular interaction of phthalocyanine derivatives, we could explain the frictional properties depending on the alkyl-chain length of phthalocyanine derivatives.