Title :

Effect of the alkyl chain and composition on the thermodynamics of mixing of small alcohols and water

Author(s) :

Idrissi, Nacer [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Jedlovszky, P. [Auteur]

Journal title :

Journal of Molecular Liquids

Abbreviated title :

J. Mol. Liq.

Volume number :

338

Pages :

-

Publication date :

2021-09-09

ISSN :

0167-7322

English keyword(s) :

Thermodynamic integration
Computer simulation
Thermodynamics of mixing
Alcohol-water mixtures

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

The thermodynamic changes occurring upon mixing small monovalent alcohols and water are systematically analyzed as a function of both the size and shape of the apolar group of the alcohols and of the mixture composition. ...
Show more >The thermodynamic changes occurring upon mixing small monovalent alcohols and water are systematically analyzed as a function of both the size and shape of the apolar group of the alcohols and of the mixture composition. For this purpose, the Helmholtz free energy, energy and entropy of mixing of the eight smallest alcohols, i.e., methanol, ethanol, propanol, isopropanol, butanol, isobutanol, s-butanol, and t-butanol with water are calculated in the entire composition range by means of Monte Carlo simulations and thermodynamic integration with three different model combinations. The obtained results are in a satisfactory agreement with existing experimental data. In particular, they are able to well reproduce the qualitative trends, being in the focus of this study. Our results indicate that the thermodynamics of mixing of these systems is primarily governed by the entropic term. In particular, the addition of alcohol to water-rich systems induces an ordering of the water molecules through hydrophobic hydration, while the addition of water to alcohol-rich mixtures induces ordering of the alcohol molecules by providing them additional H-bonds. According to the obtained free energy of mixing data, the former of these two effects clearly becomes more pronounced with increasing size and decreasing branching (i.e., increasing surface area) of the apolar groups, while the latter one is much less sensitive to the apolar tail. As a consequence, the increase of the apolar tail (and the decrease of its branching) leads to partial miscibility of the alcohols with water, with a miscibility gap occurring in water-rich compositions.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Submission date :

2024-02-28T23:34:15Z
2024-03-15T10:31:38Z