CURVATURE CAPILLARITY OF LAMELLAR PHASES

We study the free surface shape of thick lamellar films whose layer curvature and surface energies can compare. A new capillarity appears with a mesoscopic or even macroscopic screening length mu. Under external constraints, instabilities with period mu are expected to develop. These results would extend to ''loose'' lamellar drops laid on non-faceting substrates. Typical experiments could check these predictions. Tubular cylinders of size mu could exist.