FTIR spectroscopy and nanotribological comparative studies: influence of the adsorbed water layers on the tribological behaviour

Under ambient conditions, a water film is always present on a silica substr ate and generates additional capillary forces between the nanotip and the s tudied surface. In the present paper. we report AFM measurements of pull-of f and friction forces as a function of the temperature and a comparative FT IR spectroscopy study. The AFM results show a net decrease of the forces as the temperature increases, while the IR spectroscopy indicates that the li quid film is removed at high temperature. Consequently, we deduce that a li quid neck is created between the tip and the surface and that the forces me asured are mostly capillary forces. The present work shows that temperature studies with AFM can be a useful way to probe the influence of the capilla ry force in turn to characterize surface properties.