Résumé
The influence of different salts on the lower critical solution temperature (LCST) of mixtures of propylene glycol propyl ether and of dipropylene glycol propyl ether with water was determined experimentally. It was observed that the temperature shifts follow precisely the same Hofmeister series for anions that was originally found for salting-in and salting-out effects for protein solutions. The results are similar to the observations found for mixtures of water with non-ionic surfactants. In the case of dipropylene glycol propyl ether mixtures with water, temperature dependent phase diagrams in the presence of one salting-in (NaSCN) and one salting-out (Na 2 SO 4 ) salt were measured at a fixed salt concentration in water of 0.041 M. The results can be qualitatively understood by assuming a different hydrophobicity for both types of salts. They further hint at a strong degree of solute determined cooperative water structure.