Regensburg 2013 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: Poster: Colloids and Complex Liquids

CPP 20.14: Poster

Dienstag, 12. März 2013, 18:15–20:15, Poster C

Structure of confined microemulsions in AAO nanopores — •Frederik Lipfert and Henrich Frielinghaus — Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, 85747 Garching

Microemulsions are used in a variety of different applications such as detergence or oil recovery where they are exposed to a variety of surfaces and confinements. We analyzed the structure of symmetrical microemulsions with different surfactant concentrations in two-dimensional confinement using cylindrical nano pores arranged hexagonally on anodized aluminum oxide (AAO) membranes. The microemulsions we used have a water-oil domain sizes in the range of 200Å while the pores we used have diameters of 180nm and 400nm. We found the microemulsion exhibiting a lamellar, shell-like structure at the interface even tough their equilibrium state is bicontinuous. We used small angle neutron scattering for the analysis because of the neutron wavelength being comparable to the examined structures and the possibility of contrast matching the microemulsion to the AAO membranes by partly replacing the H2O with D2O. This matching suppresses the scattering from the membrane which would overshadow the scattering from the microemulsion and makes the microemulsion scattering accessible. The scattering from the interface near lamellar structure is Bragg like while the scattering from the bicontinuous microemulsion in the pore center is isotropic. Both structures have the same domain size so in order to distinguish between both structures we set up the sample perpendicular to the incoming neutron beam then turned it 15° making the scattering from the lamellar structure visible.