How do closed-compact multi-lamellar droplets form under shear flow? A possible mechanism

The formation of closed-compact multi-lamellar droplets obtained upon shearing both a lamellar phase (L-alpha) and a two-phase separated lamellar-sponge (L-alpha-L-3) mixture is investigated as a function of the shear rate (gamma)over dot, using small-angle light scattering (SALS) and cross-polarized optical microscopy. In both systems the formation of droplets occurs homogeneously in the cell at a well-defined wave vector q(e) proportional to (gamma)over dot(1/3) via a strain-controlled process. These results suggest that the formation of droplets may be monitored in both systems by a buckling instability of the lamellae as predicted from a recent theory.