The effect of polymer molar mass on the aqueous two-phase system containing Poly ethylene glycol dimethyl ether and ammonium sulphate and its application of this system in partitioning of iodine

The partitioning of iodide was studied in an aqueous two phase system (ATPS) comprised of ammonium sulphate, poly ethylene glycol dimethyl ether (PEGDME), and water at 298.15 K. To investigate the effect of molar mass of the polymer on the tie-line, similar measurements were also made at T=298.15 K on this two phase system consisting of the PEGDME with molar masses of 250, 500 and 2000 g.mol-1. Finally the effect of molar mass of polymer on the binodal of {PEGDME + ammonium sulphate +water} was studied by measuring liquid-liquid equilibrium at T= 298.15 K for three different molar masses. The experimental binodal data were described using two empirical nonlinear three parameter expressions developed by Merchuk and Zafarani Moattar et al. The increase in the polymer molar mass provides ATPS with larger biphasic region. The tie-line compositions were estimated and correlated using the Othmer–Tobias and Bancroft and Setschenow type equations. In addition the partitioning behavior of the iodine molecule on the investigated aqueous two-phase system was studied.