Self-assembly of magnetic poly(ionic liquid)s and ionic liquids in aqueous solution

Abstract

In this paper, an amphiphilic magnetic ionic liquid monomer (DHMTA[FeCl₄]) with a long dodecyl chain was prepared. Kinetics study showed that the FeCl₄ anion will poison the polymerization. However, controlled PDHMTA[FeCl₄] was prepared by living ring-opening metathesis polymerization of DHMTA[Cl] followed by complexing with FeCl₃. Both the magnetic monomer and polymer were self-assembled in aqueous solution. PDHMTA[FeCl₄] self-assembled into multi-layer structures with a stretched bipolymer as one layer, and the hydrophilic ion pairs were located at the periphery of the layers, whereas DHMTA[FeCl₄] was self-assembled into a shuttle shape with a hydrophobic core and hydrophilic shell. By introducing FeCl₄⁻ as a counter ion, the monomer and polymer were magnetically responsive, and the contrast for the TEM image of the self-assemblies was greatly enhanced.