Spreading and instabilities induced by a solutal Marangoni effect

We study the spreading of liquid films driven by surface tension gradients induced by evaporation from a two-component mixture. The films climb from a macroscopic reservoir on a plane tilted surface and their length L is found to depend linearly on the square root of time t: L(t) = (Dt)(0.5). We develop a semiquantitative analysis that shows which parameters control the value of D for ideal mixtures and for nonidealones. We report also experimental results about the time evolution and the spatiotemporal behavior of the interfacial instability that develops at the meniscus between the reservoir and the film. Results agree well with previous experimental and theoretical studies.