Liquid-liquid equilibrium data for the ionic liquid N-Ethyl-pyridinium bromide with several sodium salts and potassium salts

Abstract

The liquid-liquid equilibrium (LLE) data for systems containing N-ethyl-pyridinium bromide ([EPy]Br), salt (Na 2 HPO 4, K 2 HPO 4, K 2 SO 4, C 4 O 6 H 4 KNa), and water have been measured experimentally at T = 298.15 K and the formations of these four aqueous two-phase systems (ATPSs) have been discussed. Also, the effective excluded volume (EEV) values obtained from the binodal models for the four systems were determined and the salting-out abilities of different salts follow the order of K 2 SO 4 > K 2 HPO 4 > Na 2 HPO 4 > C 4 O 6 H 4 KNa. The solubility data were correlated by the Merchuk and other equations while the tie-line data by the Othmer-Tobias, Bancroft, two-parameter, and Setschenow-type equations. The correlation coefficients evidenced that experimental data fitted well to all these equations. These four salts were proved successfully to form ATPSs with N-ethyl-pyridinium bromide, making a significant contribution to the further study of this kind of ATPS. © 2013 Yuliang Li et al.