Equilíbrio líquido-líquido em misturas de sais inorgânicos com polímeros ou líquidos iônicos em meio aquoso

Abstract

The study aimed to collect data from the experimental liquid-liquid equilibrium for aqueous two-phase systems (ATPS) formed by PEG (1500 or 4000 g mol-1) + sodium sulfite + water, or ionic liquid (IL) [Bmim]BF4 + manganese sulphate + water at several temperatures. In the diagrams obtained for the ATPS formed by PEGs was show to increase the biphasic region with increasing temperature, showing process endothermic phase segregation. Different behavior was examined for the system formed by ionic liquid where the process of phase separation occurred with a biphasic reduction of area by raising the temperature, featuring an exothermic process, and still observed a peculiar characteristic of phase inversion generated by changes in composition and temperature. After obtaining the experimental diagrams for different ATPS results were treated with thermodynamic models to obtain a better understanding and control of physicochemical behavior of these systems. In this sense, the ATPS formed by PEG had binodal curves relating to the delimitation of the regions monophasic/biphasic and data correlated liquid-liquid equilibrium equations of Othmer-Tobias and Bancroft, and NRTL and UNIQUAC models respectively. In the mixtures formed by IL, the salting out effect in the phase separation process was quantitatively assessed by Setschenow equation and the Marchuk and NRTL models were also used for theoretical correlation of the data.