Wetting properties of glycerol on silicon, native SiO2, and bulk SiO2 by scanning polarization force microscopy

Scanning polarization force microscopy, a relatively new non-contact scanning probe microscopy technique, was applied in order to investigate the properties of liquid surfaces (droplets), such as: topography, microscopic contact angle , surface potential energy P(e), spreading coefficient S, and disjoining pressure ?. Investigations were carried out on glycerol droplets deposited on surfaces of bare silicon, silicon covered with native oxide, and bulk silicon oxide. Contact angle values were determined from directly measured topography profiles of micro- and nanodroplets. Values of surface potential energy, spreading coefficient, and disjoining pressure were calculated based on a model of the dependence of contact angle on droplet height. The results of these experiments offer valuable insights into the mechanisms of wetting phenomena at the microscopic scale.