Self-similarity and pattern selection in the roughening of binary liquid films

Films of spinodally decomposing binary liquid mixtures show transient wetti ng of both confining interfaces by one of the phases, and rupture, with cha racteristic wavelength lambda (c) and time T-rupture, leading to flat dropl ets of the nonwetting phase encapsulated by the wetting phase. Over the ent ire range of film thicknesses d approximate to 100-3500 nm, we find T-ruptu re proportional to d(1.01 +/-0.08), indicating film structures that scale s elf-similarly with d, and find also that lambda (c) approximate to 60d(0.97 +/-0.03), the large prefactor suggesting a rupture wavelength which minimi zes the interfacial tension of the roughened film.