Some experiments on the Marangoni effect

An experimental study of the spreading and dissolving of thin liquid films under the action of surface forces is presented. The method consists of the continuous feeding of a liquid over the surface of another liquid into which it dissolves; the steady film thus obtained covers only a part of the supporting liquid surface, dependent on the flow rate of the liquid fed. The dependence of the radius of the film contour on flow rate and concentration driving force is obtained for various film forming liquids dissolving into water. By using a Schlieren technique the film contour and the flow pattern outside the film contour are studied, several structures being evidenced.