Original scientific paper

https://doi.org/10.5562/cca4193

Influence of Temperature and NaCl Impurities on Molecular Interactions in 1,4-Dioxane–Water Mixtures: A Grunberg–Nissan Model Analysis

Lilia Ajroudi ; University of Tunis, Preparatory Institute for Engineering studies of Tunis. Materials and Fluids Laboratory. Tunisia
Moez Guettari ; University of Tunis, Preparatory Institute for Engineering studies of Tunis. Materials and Fluids Laboratory. Tunisia
Ahmed El Aferni orcid.org/0000-0002-2509-0845 ; University of Tunis, Preparatory Institute for Engineering studies of Tunis. Materials and Fluids Laboratory. Tunisia *
Renato Tomaš ; University of Split, Faculty of Chemistry and Technology, Ruđera Boškovića 35, HR-21000 Split, Croatia
Tahar Tajouri ; University of Tunis, Preparatory Institute for Engineering studies of Tunis. Materials and Fluids Laboratory. Tunisia

* Corresponding author.

Abstract

The 1,4-dioxane-water system is of significant relevance in pharmaceutical development, Chemical Engineering and other industrial processes. In this study, we investigate the intermolecular interactions in 1,4-dioxane–water mixed solvent system under different temperatures and NaCl concentrations using the Grunberg–Nissan approach. As first step, the solubility parameters of the mixture is evaluated as a function of the water molar fraction (xw) at 25 °C based on Hansen solubility parameters. The analysis shows that dispersion forces dominate for xw < 0.7, whereas hydrogen-bonding interactions become predominant at xw  0.7. These findings are consistent with previous microscopic techniques. A new expression of the Gruenberg-Nissan constant, was established and calculated over the molar fraction of water at 25 °C, and thus the complexes formed from 1,4-dioxane and water are discussed. Furthermore, a theoretical expression for the temperature dependence of the Grunberg–Nissan constant was introduced to assess the influence of thermal effects on complex stability. The derivative, is introduced to assess the thermal stability of the complex. Finally, the impact of ionic impurities (Na+ and Cl–) on the interaction between water and dioxane molecules was evaluated through a pseudo-Grunberg–Nissan constant, providing insights into how salt addition modifies mixture stability.

Keywords

mixed liquids; complex; Grunberg-Nissan constant; stability; temperature; ion

Hrčak ID:

342924

URI

https://hrcak.srce.hr/342924

Publication date:

31.12.2025.

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