Potential for desalination using lower critical solution temperature polymers: Concentration of salt solutions by pluronic PE6200

A commercially available lower critical solution temperature (LCST) polymer was demonstrated to preferentially adsorb water containing a reduced ion concentration, from CrCl₃ salt solutions and release some of this scavenged water at higher temperatures. The scavenging ability of the polymer was demonstrated to be dependent on the bulk salt concentration. The volume of water scavenged and the concentration of the remaining CrCl₃ solution increased linearly with the amount of LCST polymer (Pluronic PE 6200) used. Both the volume of water removed and the amount by which the remaining CrCl₃ solution was concentrated decreased with increasing CrCl₃ concentration. Implications for research into a novel method for sea water desalination are addressed. We also show water extraction from dilute sodium chloride and sea water, and that these results are consistent with the CrCl₃ model system.