Thermodynamics and Phase Partitioning Dynamics in [Bmim]BF ₄ /Magnesium Sulfate Aqueous Two-Phase Systems

High Resolution Image Download MS PowerPoint Slide Research on aqueous two-phase systems (ATPSs) with ionic liquids drives innovation in separation technologies, offering groundbreaking insights that fuel advancements in biotechnology, environmental science, and chemical engineering. This study aimed to obtain and characterize ATPSs formed by the mixture of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF 4 ), magnesium sulfate (MgSO 4 ), and water at temperatures of 278.15, 288.15, 298.15, 308.15, and 318.15 K. The effects of mixture composition, temperature, and cation type on phase behavior were evaluated. The experimental results indicated that lower temperatures favored phase separation, characterizing an exothermic process. Additionally, decreasing the temperature led to phase inversion under certain mixture conditions. Quantitative analysis of the species involved in the liquid–liquid equilibrium revealed no significant exchanges between the original ion pairs. The phase-forming ability of MgSO 4 was compared with that of related [Bmim]BF 4 -based ATPSs formed with other sulfate salts, keeping S O 4 2 − as the common counterion and highlighting the salting-out effect within this sulfate-salt series. These findings provide a solid foundation for understanding the equilibrium mechanisms in IL-based ATPSs, contributing to the development of new industrial applications in separation processes.