Perturbation of water-ethanol solvent structural relaxation by a bis-urea supramolecular gel and paracetamol

Morbidini, Riccardo and Edkins, Robert M. and Nemkovskiy, Kirill and Nilsen, Gøran and Seydel, Tilo and Edkins, Katharina (2025) Perturbation of water-ethanol solvent structural relaxation by a bis-urea supramolecular gel and paracetamol. Journal of Chemical Physics. ISSN 0021-9606 (In Press)

[thumbnail of Morbidini-etal-JCP-2025-Perturbation-of-water-ethanol-solvent-structural-relaxation] Text. Filename: Morbidini-etal-JCP-2025-Perturbation-of-water-ethanol-solvent-structural-relaxation.pdf
Accepted Author Manuscript
Restricted to Repository staff only until 1 January 2099.

Download (2MB) | Request a copy

Abstract

Understanding structural dynamics on the picosecond/nanometer scale in complex fluids is crucial for advancing various fields, from material chemistry to drug delivery. We employ polarized quasi-elastic neutron spectroscopy to investigate the perturbation to the hydrogen-bond network of water-ethanol mixtures induced by a supramolecular gel network and by paracetamol (PCM) molecules. Interestingly, while the supramolecular gelator significantly alters the macroscopic behavior of the solvent at concentrations of 0.3 and 0.5 wt.%, it does not affect the hydrogen bond network at the microscopic level. In contrast, the addition of PCM at 5 wt.%, which does not change the macroscopic properties, modifies the structural dynamics of water-ethanol mixtures at length scales commensurate with and below the PCM-PCM correlation length in the mixture. This study reveals the intricate interplay between solute, solvent, and gel interactions, demonstrating a lack of direct correlation between macroscopic and microscopic properties in such complex systems.

ORCID iDs

Morbidini, Riccardo, Edkins, Robert M. ORCID logoORCID: https://orcid.org/0000-0001-6117-5275, Nemkovskiy, Kirill, Nilsen, Gøran, Seydel, Tilo and Edkins, Katharina ORCID logoORCID: https://orcid.org/0000-0002-6885-5457;