Predicting Water-Induced Demixing of Ionic Liquid Mixtures with Associative Electrolyte PC-SAFT
5 affiliations
- 1Laboratoire de Chimie, ENS Lyon and CNRS, 46 allée d'Italie, Lyon, France, 69364
- 2Department of Chemistry
- 3Norwegian University of Science and Technology
- 4Instituto de Química
- 5Universidade de São Paulo
Abstract
Ionic liquids (ILs) can be mixed with other ILs to fine-tune their physicochemical properties. While ILs have been long considered inseparable, recent studies have demonstrated that the controlled addition of water enables the selective recovery of the constituent salts, opening new opportunities for sustainable IL recycling and separation. The rational design of these IL mixtures remains challenging due to the lack of predictive models capable of accurately capturing the interplay between competing short- and long-range interactions in IL-based systems, particularly in multi-IL systems, thereby limiting our ability to guide both the selection of optimal IL components and the development of efficient post-mixing recovery strategies. We propose in this work an associative electrolyte PC-SAFT (aePC-SAFT) model, that incorporates, in a physically balanced manner, the short-range dispersion and hydrogen bonding interactions, as well as the long-range Coulomb interactions. Ion-specific parameters are obtained from homologous series of [CnC1Im][NTf2] (1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide) and [C4C1Im][OAc] (1-butyl-3-methylimidazolium acetate), and subsequently transferred to functionalized ILs, including [C3OC1Im]+ (1-methoxyethyl-3-methylimidazolium), based on the liquid-liquid equilibria (LLE) and density of their mixtures with water and hydrocarbons. Without additional parameter adjustment, the model accurately predicts the LLE of binary and ternary IL-water systems, including the ether-functionalized ILs. This work establishes a robust, predictive, and physically grounded framework for modeling the thermodynamic behavior of ILs, enabling the rational design and optimization of separation processes in IL-based systems.
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BibTeX
@misc{yang2026predicting,
title = {{Predicting Water-Induced Demixing of Ionic Liquid Mixtures with Associative Electrolyte PC-SAFT}},
author = {Fufang Yang and Beatriz R. de Moraes and Rômulo A. Ando and Agílio A. H. Pádua and Margarida Costa Gomes},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010168/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010168/v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Predicting Water-Induced Demixing of Ionic Liquid Mixtures with Associative Electrolyte PC-SAFT
AU - Fufang Yang
AU - Beatriz R. de Moraes
AU - Rômulo A. Ando
AU - Agílio A. H. Pádua
AU - Margarida Costa Gomes
PY - 2026
DA - 2026/10/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010168/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010168/v1
AB - Ionic liquids (ILs) can be mixed with other ILs to fine-tune their physicochemical properties. While ILs have been long considered inseparable, recent studies have demonstrated that the controlled addition of water enables the selective recovery of the constituent salts, opening new opportunities for sustainable IL recycling and separation. The rational design of these IL mixtures remains challenging due to the lack of predictive models capable of accurately capturing the interplay between competing short- and long-range interactions in IL-based systems, particularly in multi-IL systems, thereby limiting our ability to guide both the selection of optimal IL components and the development of efficient post-mixing recovery strategies. We propose in this work an associative electrolyte PC-SAFT (aePC-SAFT) model, that incorporates, in a physically balanced manner, the short-range dispersion and hydrogen bonding interactions, as well as the long-range Coulomb interactions. Ion-specific parameters are obtained from homologous series of [CnC1Im][NTf2] (1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide) and [C4C1Im][OAc] (1-butyl-3-methylimidazolium acetate), and subsequently transferred to functionalized ILs, including [C3OC1Im]+ (1-methoxyethyl-3-methylimidazolium), based on the liquid-liquid equilibria (LLE) and density of their mixtures with water and hydrocarbons. Without additional parameter adjustment, the model accurately predicts the LLE of binary and ternary IL-water systems, including the ether-functionalized ILs. This work establishes a robust, predictive, and physically grounded framework for modeling the thermodynamic behavior of ILs, enabling the rational design and optimization of separation processes in IL-based systems.
ER -