Publication 546

Laboratoire d'Electrochimie Moléculaire, UMR 7591, Université Paris 7- Denis Diderot - CNRS, 75251 Paris, Cedex 05, France, Laboratoire de Technologie Enzymatique, UMR 6022, Université de Technologie de Compiègne, BP 20529, 60205 Compiègne, France, and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France

Small-angle neutron scattering (SANS) is used to characterize a phospholipid/alkoxysilane hybrid bilayer membrane (HBM), a model of biological membrane, supported in anisotropic porous alumina (Al₂O₃). The bilayer is obtained by fusion of phospholipid vesicles with a hydrophobic alkoxysilane monolayer chemically bound to the microporous alumina support. We first characterized the bare alumina material, then the alkoxysilane (OTS) layer bound to alumina, and finally the hybrid bilayer. By orienting the anisotropic support, we show that the intensity can be considerably increased, enabling the scattering to be measured in a wide q range (6 × 10^-4 - 0.5 Å^-1) corresponding to 9-10 decades in intensity and down to 10^-4 cm^-1. This enables us to cover the structure factor of the oxide at large scale, the wide Porod regime, and the membrane form factor. Analysis of the scattering curves indicates that both the OTS layer and the HBM produce very smooth, uniform, and continuous layers at the alumina/solvent interface. This new approach in the characterization by SANS of a supported membrane in a porous material provides information on the homogeneity, the specific area, the roughness, and the thickness of the bilayer.