Wetting-induced anisotropic structure at the interface of a glass and a sponge phase

Wetting a glass surface with a sponge phase is shown to induce an anisotropic, presumably lamellar, interface structure. This static effect, and the corresponding induced birefringence measurements, are described in the framework of a theoretical phase diagram involving the sponge and lamellar phases, and taking into account a surface field and the existence of a transition between two, direct and inverted, sponge regions.