Spatial mapping and scaling of the shear-induced transformation from bicontinuous microemulsions towards lamellar structures by coupling microfluidics and SANS

Coupling microfluidics and small-angle neutron scattering (SANS), we investigate the influence of shear flow on a model bicontinuous microemulsion of D 2 O/ n -octane/C 10 E 4 , examining the role of membrane volume fraction in the transformation towards a lamellar structure. We employ a contraction-expansion geometry with flow velocities in excess of 10 m s −1 and spatially map the microfluidic field using a small SANS beam, illuminating down to 10 nL sample volumes. The shear-induced, progressive, bicontinuous-to-lamellar transition is found to be promoted by additional extensional flow (>10 3 s −1 ), while fast relaxation kinetics (