Smectic membranes in aqueous environment

We present a study of thermotropic smectic liquid crystal films in aqueous environment. Macroscopic freely suspended films in water with a size up to 7.4×15 mm2 were prepared with the help of a surfactant, which ensures a strong homeotropic anchoring at liquid crystal/water interfaces. The films were studied by optical microscopy and ellipsometry. Attention was paid to the stability and the thinning transitions which occurred at temperatures above the bulk smectic- A -isotropic transition temperature. In addition, we investigated the formation and rupture kinetics of thin smectic membranes separating water droplets in microfluidic devices. Besides possible applications in discrete microfluidics, smectic films in aqueous environment may expand the general range of possible studies of freely suspended smectic films.