Ultrathin liquid films. Ellipsometric study and AFM preliminary investigations

Films of molecular thickness exhibit a large variability, both in their structural properties and in their spreading dynamics. The thickness profiles of nonvolatile liquid microdroplets spreading spontaneously on smooth solid surfaces provide information on short range liquid-liquid and liquid-solid interactions. These profiles can in principle be recorded by various techniques, including spatially resolved ellipsometry and atomic force microscopy (AFM). The main part of the paper deals with results obtained using ellipsometry. In particular, the influence of water adsorbed on the substrate on the spreading dynamics of various liquids is reported. Unexpected absorbed on the substrate on the spreading dynamics of various liquids is reported. Unexpected problems met with the AFM technique are discussed, further work is under way