Liquids in narrow spaces

How does spatial confinement affect the microscopic structure of liquids?

This is a question which is receiving increasing attention from condensed matter physicists. Liquids are characterized by a short-ranged, so-called local structure, and it has been predicted theoretically about 25 years ago that confinement induces anisotropy in the local structure, and hence many properties, of liquids. However, this prediction had not been experimentally verified previously. Here, we have combined x-ray scattering experiments from colloid-filled nanofluidic channel arrays, a technique developed at PSI, with a state-of-the-art inhomogeneous liquid-state theory, to provide the first experimental verification of the theoretically predicted anisotropic local structure of confined liquids. The simultaneous experimental and theoretical description of confined liquids at this level allows accurate studies of the interaction mechanisms in liquids under spatial confinement.