Surface Potential Images of Microstructured Organosilane Self-Assembled Monolayers Acquired by Kelvin Probe Force Microscopy

Abstract
Kelvin probe force microscopy (KFM) has been applied to acquiring surface potential images of a coplanar microstructure composed of two self-assembled monolayers (SAMs) prepared from octadecyltrimethoxysilane (ODS) and fluoroalkylsilane (FAS), that is, heptadecafluoro-1,1,2,2-tetrahydro-decyl-1-trimethoxysilane. The regions terminated with ODS and FAS could be clearly distinguished by KFM with a surface potential difference between the ODS and FAS-terminated surfaces. The surface potential of the FAS-terminated region was 190 mV lower than the potential of the ODS-terminated surface due to a larger dipole moment of the FAS molecules induced by the electron negativity of F atoms.