Liquid-liquid equilibrium is used in aquese biphase systems to isolate and purify biological materials from complex mixtures. Until now, four types of aquese biphase systems have been used in cluding Polymer-polymer systems, polymer-salt systems, ionic liquids-based systems and surfactant-based systems. Recently, liquid-liquid biphase systems have been considered, including ionic liquids and a salt or polymer for extraction and purification of different materials such as biomolecules. In this research, liquid-liquid equilibrium of three-dimensional aqueous polymer solutions and aqueous solutions of ionic liquid using the method of determining the cloud points, from the thermodynamic point of view, in three parts and in each section, the effect of two factors of salt type and salt concentration was studied. In the first part, the cloudy temperature of polypropylene glycol 1000 in pure water and in water solutions including different molecules of salts (NaCl, Na3Cit, K3Cit, Na2SO4, Na2CO3,DTAB and SDS). The cloudy temperature of the polypropylene glycol 1000 was cloudy in aqueous solutions with a mole ratio of 0.05 ions of liquids measured (1-ethyl-3-methyl-imidazolium bromide,1-butyl-3-methyl-imidazoliumbromide,1-octyl-3-methyl imidazoliumbromide,1-octyl-3-methyl-imidazoliumchloride,1-butyl-3methyl imidazolium hexafluorophosphate and1-Butyl-3-methyl-imidazolium tetra- fluoroborate).The results show that the aqueous polypropylene glycol solution (PPG1000) - salts (NaCl, Na3Cit, K3Cit, Na2SO4 and Na2CO3) at a lower temperature than the critical temperature form a aquese biphase system demonstrate salting out effect. And aqueous solution of polypropylene glycol In the second part, the cloudy temperature of 1-butyl-3-methyl- imidazolium hexafluorophosphate (C4mimPF6) in pure water and in aqueous solutions with various molecules of salts (NaCl, Na3Cit, K3Cit, Na2SO4, Na2CO3 and SDS) was measured. The degree of hydrophilicity of salts as well as their abilities in salting
