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A series of strongly microphase-separated polymerized ionic liquid (PIL) diblock copolymers, poly(styrene-b-1-((2-acryloyloxy)ethyl)-3-butylimidazolium bis(trifluoromethanesulfonyl)imide) (poly(S-b-AEBIm-TFSI)), were synthesized to explore relationships between morphology and ionic conductivity. Using small-angle X-ray scattering and transmission electron microscopy, a variety of self-assembled nanostructures including hexagonally packed cylinders, lamellae, and coexisting lamellae and network morphologies were observed by varying PIL composition (6.6–23.6 PIL mol %). At comparable PIL composition, this acrylate-based PIL block copolymer with strong microphase separation exhibited ∼1.5–2 orders of magnitude higher ionic conductivity than a methacrylate-based PIL block copolymer with weak microphase separation. Remarkably, we achieved high ionic conductivity (0.88 mS cm–1 at 150 °C) and a morphology factor (normalized ionic conductivity, f) of ∼1 through the morphological transition from lamellar to a coex...

A series of polymerized ionic liquid (PIL) block and random copolymers were synthesized from an ionic liquid monomer, 1-[(2-methacryloyloxy)ethyl]-3-butylimidazolium bis(trifluoromethanesulfonyl)imide (MEBIm-TFSI), and a nonionic monomer, methyl methacrylate (MMA), at various PIL compositions with the goal of understanding the influence of morphology on ion transport. For the diblock copolymers, the partial affinity between the PIL and PMMA blocks resulted in a weakly microphase-separated morphology with no evident long-range periodic structure across the PIL composition range studied, while the random copolymers revealed no microphase separation. These morphologies were identified with a combination of techniques, including differential scanning calorimetry, small-angle X-ray scattering, and transmission electron microscopy. Surprisingly, at similar PIL compositions, the ionic conductivity of the block copolymers were ca. 2 orders of magnitude higher than the random copolymers despite the weak microphase...

Imidazole-based ABA triblock copolymers prepared using nitroxide-mediated polymerization achieved a microphase-separated morphology with ion-conducting central blocks. Difunctional random poly(1-(4-vinylbenzyl)imidazole-co-n-butyl acrylate) (poly(VBIm-co-nBA)) central blocks provided low glass transition temperature (Tg) phases for ion conduction, and subsequent chain extension for polystyrene external blocks provided mechanical reinforcement. Selective incorporation of 1-ethyl-3-methylimidazolium ethylsulfate ([EMIm][EtSO4]) into the random poly(VBIm-co-nBA) central blocks reduced the Tg of both neutral and charged imidazole-containing central blocks. Mechanical properties for ABA triblock copolymers depended on quaternization, central block composition, and ionic liquid incorporation. Ionic conductivity increased over an order of magnitude due to quaternization of imidazole and additional ionic liquid. Tuning central block composition, charge content, and ionic liquid content provided an avenue to tailo...

Zwitterionomers containing less than 13 mol % zwitterion functionality were synthesized using free radical copolymerization of n-butyl acrylate (nBA) and sulfobetaine monomers. X-ray scattering res...

Ionic conductivity in new polymerized ionic liquids is of great interest as it applies to solid-state electrolytes for electrochemical and electromechanical applications. In this study, an ionic liquid monomer was synthesized and polymerized into random copolymers and their ionic conductivity and structure were investigated as a function of copolymer composition. Both nonionic−ionic and ionic−ionic copolymers were synthesized, where the nonionic and ionic monomers were hexyl methacrylate (HMA) and a methacrylate-based imidizolium neutralized with tetrafluoroborate (BF4) or bis(trifluoromethane sulfonyl)imide (TFSI). In the nonionic−ionic copolymer, the ionic conductivity increased by over an order of magnitude with increasing HMA composition, even though the overall charge content decreased, because the addition of HMA significantly lowered the glass transition temperature. The ionic conductivity also increased by more than an order of magnitude in the ionic−ionic copolymer with increasing TFSI content, e...