liquid–liquid equilibria of aqueous two phase system containing of pegdme 2000 and (nh4)2 so4 at different temperatures and its application in partitioning of lactic acid

in this work, the liquid-liquid equilibria (lle) of (pegdme₂₀₀₀ +ammonium sulphate + water) was studied at t= (298.15, 308.15 and 318.15) k. furthermore for this system the free energies, enthalpies and entropies of cloud points were calculated at the mentioned temperatures in order to investigate the driving force for the mentioned two-phase system. for representing the experimental binodal data the merchuk equation in the original form and with the temperature dependency and an empirical equation were used. othmer-tobias and bancraft, a temperature dependent setschenow and osmotic virial equations were used to fit the tie-line data. moreover, the effect of temperature on the binodal curves and the tie-lines for the investigated aqueous two-phase system have been studied. in addition the partitioning behaviour of the lactic acid molecule on the investigated aqueous two-phase system was studied.