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RESEARCH PRODUCT
Salt-induced microheterogeneities in binary liquid mixtures
Markus BierMarkus BierHailong LiMarkus MezgerMarkus MezgerJulian MarsJulian Marssubject
Chemical Physics (physics.chem-ph)Phase transitionSpinodalMaterials scienceCharacteristic lengthCondensed Matter - Mesoscale and Nanoscale PhysicsSmall-angle X-ray scatteringScatteringThermodynamicsFOS: Physical sciences02 engineering and technologyCondensed Matter - Soft Condensed Matter010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesSolventCondensed Matter::Soft Condensed MatterIonic strengthPhysics - Chemical PhysicsMesoscale and Nanoscale Physics (cond-mat.mes-hall)Soft Condensed Matter (cond-mat.soft)0210 nano-technologyPhase diagramdescription
The salt-induced microheterogeneity (MH) formation in binary liquid mixtures is studied by small-angle x-ray scattering (SAXS) and liquid state theory. Previous experiments have shown that this phenomenon occurs for antagonistic salts, whose cations and anions prefer different components of the solvent mixture. However, so far the precise mechanism leading to the characteristic length scale of MHs has remained unclear. Here, it is shown that MHs can be generated by the competition of short-ranged interactions and long-ranged monopole-dipole interactions. The experimental SAXS patterns can be reproduced quantitatively by fitting to the derived correlation functions without assuming any specific model. The dependency of the MH structure with respect to ionic strength and temperature is analyzed. Close to the demixing phase transition, critical-like behavior occurs with respect to the spinodal line in the phase diagram.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-04-19 |