RAFT polymerization-induced self-assembly of poly(ionic liquids) in ethanol

Abstract

Poly(ionic liquids) (PILs) exhibit better durability, processability, and mechanical stability than ionic liquids. PIL self-assembly in green solvents is a well-established strategy for preparing polyelectrolytes. Reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly (PISA) has proven to be the most controllable method for synthesizing polyelectrolytes. However, there have been few reports on preparing high-order morphology PILs by RAFT-PISA. A new type of ionic monomer, 1-butyl-3-(4-vinylbenzyl)imidazolium hexafluorophosphate ([BVBIm][PF6]), was prepared from substitution reaction and ion exchange reaction of 1-butylimidazole and 4-vinylbenzyl chloride. Herein, various morphologies, including spheres, worms, and vesicles, were easily obtained via RAFT ethanolic dispersion polymerization using poly(N,N-dimethylacrylamide) (PDMA43) as the macromolecular chain transfer agent and [BVBIm][PF6] as the monomer. Dispersion polymerization kinetic experiments, dynamic light scattering, transmission electron microscopy, and differential scanning calorimetry were used to investigate the PDMA43-b-P([BVBIm][PF6]) x block nanoparticles. This efficient RAFT-PISA method for preparing functionalized PIL nano-objects with controlled morphologies represents significant progress in this field.

Solution and Film Self-Assembly Behavior of a Block Copolymer Composed of a Poly(ionic Liquid) and a Stimuli-Responsive Weak Polyelectrolyte

“…Poly­(ionic liquids) (PILs) are a special type of strong polyelectrolytes that combine the diverse functionality and unique properties of ionic liquids (ILs) with the mechanical stability, long-range ordering, and processability of polymers. − In recent years, PILs have emerged as innovative functional polyelectrolytes with applications in a variety of fields, including battery electrolytes, separations, nanomaterials, and more. − In the past decade, PILs have been combined with highly incompatible neutral polymers to form block copolymers (BCPs) either in solution or as films. These systems have been used in forming polymer films and membranes with unique nanostructures such as lamellae, cylinders, spheroids, and bicontinuous structures. ,− In solution, they can form various structures (e.g., micellar spheres, vesicles, cubosomes) that are modulated by salt environment and PIL design − in addition to traditional BCP assembly behaviors (e.g., solvent, polymer block length, concentration) . Depending on the structure, these morphologies and supramolecular interactions can enhance the properties of PILs materials, such as ion conductivity in battery electrolytes ,,, or interfacial behavior in emulsions …”