Liquid‐Liquid Equilibrium Data for the Ionic Liquid N‐Ethyl‐Pyridinium Bromide with Several Sodium Salts and Potassium Salts

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.