Effect of chain length of self-assembled monolayers on adhesion force measurement by AFM

Abstract

It has been confirmed experimentally that the adhesion force measured between an atomic force microscope (AFM) tip and the self-assembled monolayers (SAMs) has a direct correlation with the chain length of SAMs, and that the adhesion force decreases with the increase of the chain length. In this paper, a theoretical model is put forward to calculate the adhesion force between the AFM tip and the SAMs by integrating the Lennard–Jones potential. The theoretical results are in good agreement with the existing experimental results.

Keywords:

• QUASI-CONTINUUM MODEL
• ADHESION
• SAMS
• CHAIN LENGTH
• LENNARD-JONES POTENTIAL
• VAN DER WAALS FORCE
• PULL-OFF POINT