Nonspecular neutron scattering from highly aligned phospholipid membranes

We report a neutron scattering study of multilamellar membranes supported o n solid substrates. In contrast to previous work, the high degree of orient ational alignment allows for a clear distinction between specular and nonsp ecular reflectivity contributions. In particular, we demonstrate that by us ing the specific advantages of neutron optics the nonspecular scattering ca n be mapped over a wide range of reciprocal space. Several orders of magnit ude in scattering signal and parallel momentum transfer can easily be recor ded in multilamellar stacks of lipid membranes. This opens up the possibili ty to study fluctuations, and more generally lateral structure parameters o f membrane on length scales between a few Angstrom, up to several mu m. The first results obtained for a system of partially hydrated 1,2-dimyristayl- snglycero-3-phosphatidylcholine (DMPC) indicate strong deviations from the predictions of the standard Caille model.