Wetting Properties at Nanometer Scale

The proposed chapter reviews a series of experimental techniques which enable the accurate quantitative study of wetting properties. The introductive part presents some of the many phenomena and processes influenced by wetting, underlining the importance of understanding the fundamental science involved. A few historical considerations about the quantitative study of wetting and related phenomena are given. Next, some of the “classical” techniques employed for studies at the macro‐ scopic scale are presented. The importance of studies of such phenomena at microand nanometer level is underlined, as a consequence of the enormous influence that microand nanodevices play in our day to day activities, and examples of quantita‐ tive studies, involving various measurement techniques, are given from literature. A description of the basic phenomena related to polarization forces in Scanning Po‐ larization Force Microscopy (SPFM) technique is given, followed by experimental details concerning the actual implementation of the technique. Examples of applica‐ tions of SPFM are given from literature (from the spreading of liquid crystals on sol‐ id substrates to studies of corrosion at nanometer level). Particularly, it is emphasized how this versatile technique was successfully used for direct measure‐ ments of contact angles for liquid microand nano-droplets, enabling the calcula‐ tion of the dependence of surface potential energy between the surfaces, the spreading coefficient and the disjoining pressure for microand nano-droplets.