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 anisotrop ic, presumably lamellar, interface structure. This static effect, and the c orresponding induced birefringence measurements, are described in the frame work of a theoretical phase diagram involving the sponge and lamellar phase s, and taking into account a surface field and the existence of a transitio n between two, direct and inverted, sponge regions.