Topological relaxation of a shear-induced lamellar phase to sponge equilibrium and the energetics of membrane fusion

We report time-resolved small angle neutron scattering (t-SANS) measurements of the topological relaxation of Couette shear-induced stacked L-alpha lamellar states to their multiconnected isotropic L-3 sponge equilibrium phases in a surfactant bilayer membrane system. Comparison of this structural relaxation time to the interval between diffusive membrane contacts, as determined from dynamic light scattering or estimated from the shear rates required for L-alpha saturation, allows us to determine the activation energy barrier to the membrane fusion process reestablishing the solution channel handles that characterize the sponge phase.