Structure and interactions in black films

Abstract

Very recent experiments carried out on black films, combining the determination of film structure by the use of X-ray reflectivity with the determination of forces by measurement of the applied pressure on the film, are presented. The main interest of our specific experimental approach compared with the usual optical methods, is the very high accuracy (ca. 1 Å) that can be achieved in the determination of the real thicknesses of black films. We present disjoining pressure isotherms of ionic and non-ionic surfactants which display [molecular steps], revealing the action of microscopic forces.