Surface charges and adhesion measured by atomic force microscope influence on friction force

A good correlation has been found between friction force measured using a ball-on-disc tribometer (normal load 200 mN) and adhesion hysteresis measured by atomic force microscopy. Both adhesion and friction forces were investigated in liquid media (water, ethanol, formamide, ethylene glycol) and involved interactions between silicon nitride and several materials (Si(1 0 0), Si(1 1 1), silica glass, DLC and TiN coatings). Despite the difference between the two scales of measurement, comparison between the measured friction force and the dissipated energy during the adhesion process has shown that the two quantities follow the same trend. Additional experiments were conducted in NaCl 10−3 M at various pH values in order to investigate surface charge effect on adhesion and friction.