Conference Presentation (Invited)

FZJ-2025-02946

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Criticality of Quasi-Binary Complex Fluids with and without Confinement

Frielinghaus, H.FZJ*

2025

Abstract: The Ising criticality of quasi-binary fluids is investigated using SANS. For confinement, either an antagonistic salt or a surfactant is added. The charge density waves that are locally planar encapsulate the binary fluid between the wavefronts and thus make the criticality 2-dimensional. Using DLS and NSE, the dynamic criticality besides the structural criticality in terms of the forward scattering and the correlation length are observed. A master curve of the diffusion constant as a function of length scales was obtained. When looking at the high-Q end of the SANS data, the critical correlation function exponent eta was obtained that can also be compared via a scaling relation to the structural criticality. The 2-dimensionally confined system lets us assume a directional exponent eta. Finally, in latest SANS measurements on ZOOM with a magnetic field, the domains were aligned and a directional exponent eta was obtained. The scaling relation rationalizes the exponent eta for the 2-dimensional confinement.

Keyword(s): Polymers, Soft Nano Particles and Proteins (1st) ; Energy (1st) ; Soft Condensed Matter (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Heinz Maier-Leibnitz Zentrum (MLZ)
3. JCNS-4 (JCNS-4)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. KWS-X: SAXS-WAXS laboratory beamline
2. No specific instrument

Appears in the scientific report 2025

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