THz Calorimetry of Electrolyte Solutions Links Water’s H-Bond Network to Macroscopic Properties
4 affiliations
- 1Unit of Length, Physikalisch-Technische Bundesanstalt, Bundesallee 100, Braunschweig, Germany, 38116
- 2Ecole Normale Superieure
- 3CNRS
- 4Physical Chemistry II, Ruhr University Bochum, Universitaetsstrasse 150, Bochum, Germany, 44780
Abstract
Understanding the macroscopic properties of aqueous electrolyte solutions over their full solubility range requires a detailed microscopic picture of water-ion interactions. We combine THz calorimetry and dimensionality-reduction techniques to demonstrate that two to four spectroscopic markers are sufficient to describe ion-specific variations in mixing entropies and enthalpies, viscosity, and limiting conductivity across 19 electrolytes. Those markers allow us to classify electrolytes as ’strong’ or ’weak’ and report on changes in the water’s H-bond network. As concentration increases, spectroscopic nonlinearities due to ion aggregation appear that, based on a multipole expansion model for activities, are correlated with density changes. For CsI and LiCl, as prototypes of weak and strong electrolytes, respectively, the multipole expansion model accurately describes their conductivities, viscosities, and surface tensions. THz spectroscopy in combination with an activity coefficient model directly correlates macroscopic solution properties with changes in the H-bond network, paving the way towards efficient machine-learning approaches.
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BibTeX
@misc{ma2026calorimetry,
title = {{THz Calorimetry of Electrolyte Solutions Links Water’s H-Bond Network to Macroscopic Properties}},
author = {Chun Yu Ma and Simone Pezzotti and Martina Havenith and Gerhard Schwaab},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010693/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010693/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - THz Calorimetry of Electrolyte Solutions Links Water’s H-Bond Network to Macroscopic Properties
AU - Chun Yu Ma
AU - Simone Pezzotti
AU - Martina Havenith
AU - Gerhard Schwaab
PY - 2026
DA - 2026/10/20
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010693/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010693/v1
AB - Understanding the macroscopic properties of aqueous electrolyte solutions over their full solubility range requires a detailed microscopic picture of water-ion interactions. We combine THz calorimetry and dimensionality-reduction techniques to demonstrate that two to four spectroscopic markers are sufficient to describe ion-specific variations in mixing entropies and enthalpies, viscosity, and limiting conductivity across 19 electrolytes. Those markers allow us to classify electrolytes as ’strong’ or ’weak’ and report on changes in the water’s H-bond network. As concentration increases, spectroscopic nonlinearities due to ion aggregation appear that, based on a multipole expansion model for activities, are correlated with density changes. For CsI and LiCl, as prototypes of weak and strong electrolytes, respectively, the multipole expansion model accurately describes their conductivities, viscosities, and surface tensions. THz spectroscopy in combination with an activity coefficient model directly correlates macroscopic solution properties with changes in the H-bond network, paving the way towards efficient machine-learning approaches.
ER -