Determination and Thermodynamic Modeling of the Ternary ([BMIm]Br + LiBr + H2O) System at T=298.2 and 308.2K

During recent years, ionic liquids due to their unique physical and chemical properties haveattracted great interest [1-2]. Ionic liquids have been widely used in various fields of application.The presence of ionic liquids in a process needs a deeper knowledge about the thermodynamicbehaviour of the mixtures. One method of the study of the thermodynamic properties of thesemixtures is the potentiometric method [3]. In this work, thermodynamic study of the aqueouselectrolyte system containing 1-buthyle-3-methyl imidazolium bromide ([BMIm]) and lithiumbromide (LiBr) was carried out on the galvanic cell of the type:[ BMIm] -ISE │ [BMIm] Br(m1), LiBr (m2), H2O │Br-ISE on total ionic strengths from 0.01 to 2.80 mol.kg-1. Variousseries of the salt molal ratios (r= mLiBr / m[BMIm]Br = 10, 7.5, 5) were used at T= 298.2 and308.2 K and P = 0.1 MPa. The experimental mean activity coefficients of [BMIm]Br in theaqueous solution were determined by using the emf measurements in according to Nernstequation. The Pitzer ion-interaction model was used to analyze the studied system. The Pitzermixing interaction parameters were evaluated for the mixed electrolyte system. The obtainedparameters were used to calculate the mean activity coefficients of the solute species, theosmotic coefficients and excess Gibbs free energies for the whole series of the mixed electrolytesystems.

کلیدواژه ها:

Activity Coefficient ، Potentiometric Method ، Pitzer Ion-Interaction Mode ، 1-buthyle-3- methyl Imidazolium Bromide ، Lithium Bromide