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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 4: Crystallization, Nucleation and Self-Assembly I
CPP 4.3: Vortrag
Montag, 17. März 2025, 12:00–12:15, H34
How Aqueous Solutions of Low-end Mono-alcohols Crystallize? — •Vasileios Moschos1 and George Floudas1,2 — 1Department of Physics, University of Ioannina, 45110 Ioannina, Greece — 2Max Planck Institute for Polymer Research, 55128 Mainz, Germany
Aqueous solutions of low-end aliphatic mono-alcohols, such as ethanol and 1-propanol, display several peculiar features originating from hydrogen bonding, and in particular, antagonistic hydrophilic/hydrophobic interactions of the head/tail that give rise to local nano-heterogeneity. By combining structural (XRD), thermodynamic (Differential Scanning Calorimetry, DSC) and dynamical (Dielectric Spectroscopy, DS) probes, the pertinent phase diagrams of the two binary mixtures are established, comprising of liquid 1-propanol/ethanol, liquid water, hexagonal ice and different hydrates. The two phase diagrams are discussed in terms of up to five different Regimes (Regime I-V), all sharing a droplet arrangement of the minority component, with the exception of Regime I in ethanol/water binary system, where molecular mixing of the two components occurs. By probing the dynamics of the mixtures over an extended frequency and temperature range, different relaxation processes are identified, either associated with with the dynamics of pure alcohol (Debye-like and α-process) or alcohol/water mixtures.
Keywords: Hydrogen Bonding; Hydrophobic Hydration; Alcohols; Phase Diagram; Dynamics