Quantitative Characterization of Nanoadhesion by Dynamic Force Spectroscopy

We present a method for the characterization of adhesive bonds formed in nanocontacts. Using a modified atomic force microscope, the nanoadhesion between a silicon nitride tip and a self-assembled monolayer of 1-nonanethiol on gold(111) was measured at different loading rates. Adhesion force-versus-loading rate curves could be fitted with two logarithmic terms, indicating a two step (two energy barrier) process. The application of the Bell−Evans model and classical contact mechanics allows the extraction of quantitative information about the effective adhesion potential and characterization of the different components contributing to nanoadhesion.