Micellar shuttle of a polymeric ionic liquid (P(EHO)-CI-P(EtOx)) in a water/ethyl acetate two-phase system: Micellar load capacity and selective transfer of molecular anions

Abstract

Selective ionic load behaviour of a polymeric ionic liquid (PIL) (poly(3-ethyl-3-hydroxymethyloxetane)-cationic-imidazolium-poly(2-ethyl-2-oxazoline) and molecular transfer in a biphasic system (water/ethyl acetate) are investigated using dissipative particle dynamics (DPD) simulations and coarse-grained models. The mesoscopic simulations show that the PIL generates stable spherical micelles in an aqueous environment at room temperature and has the selective characteristic (via a cationic-imidazolium mesh in the micellar core) to separate anionic molecules of a mixture of organic dyes (methyl orange and methyl violet). At high temperatures (≥low critical solution temperature (≈333 K)), the PIL micelles lose their thermodynamic stability via a cloud point, and the gradual insolubility of the PIL micelles in the aqueous environment promotes micellar shuttles towards the organic phase where the polymeric micellar corona is regenerated. All the transitory stages involving the selective ionic load process and maximum load capacity during micellar shuttle formation in the biphasic system are analysed in detail. Our theoretical results are in good agreement with the experimental ones. The study is expected to contribute to the understanding of the relationship between selective ionic transfer and micellar shuttle in biphasic systems under the effect of temperature.