An atomic force microscope (AFM) was used to investigate Si3N4 tip interact
ions with various materials in four different liquid media (water, ethanol,
ethylene glycol, and formamide). The adhesion forces calculated using surf
ace energies and the values measured experimentally were compared. For all
materials, the calculated adhesion force closely correlated with AFM measur
ements, except in water. In the case of water, the AFM experiments showed s
trong adhesion. whereas theoretically (van Oss-Chaudhury-Good model) repuls
ion is predicted. The difference observed is discussed in terms of the chem
ical interactions between Si3N4 and water.