VRFBs based on benzotriazole grafted polybenzimidazole / polymeric ionic liquid with high ion selectivity

Antimicrobial resistance has become a serious threat to global health. New antimicrobials are thus urgently needed. Ionic liquids (ILs), salts consisting of organic cations and anions with melting points less than 100°C, have been recently found to be promising in antimicrobial field as they may disrupt the bacterial wall and membrane and consequently lead to cell leakage and death. Different types of antimicrobial ILs are introduced in the review, including cationic, polymeric, and anionic ILs. Being the main type of the antimicrobial ILs, the review focuses on the structure and the antimicrobial mechanisms of cationic ILs. The quantitative structure-activity relationship (QSAR) models of the cationic ILs are also included. Increase in alkyl chain length and lipophilicity is beneficial to increase the antimicrobial effects of cationic ILs. Polymeric ILs are homopolymers of monomer ILs or copolymers of ILs and other monomers. They have great potential in the field of antibiotics as they provide stronger antimicrobial effects than the sum of the monomer ILs. Anionic ILs are composed of existing anionic antibiotics and organic cations, being capable to enhance the solubility and bioavailability of the original form. Nonetheless, the medical application of antimicrobial ILs is limited by the toxicity. The structural optimization aided by QSAR model and combination with existing antibiotics may provide a solution to this problem and expand the application range of ILs in antimicrobial field.

Quaternized adamantane-containing poly(aryl ether ketone) anion exchange membranes for vanadium redox flow battery applications

Owing to their robust and tunable properties compared to molecular compounds, ionic liquids and their high molecular weight counterparts, polymeric ionic liquids, have provided suitable compounds for the development of smart materials with high physical and chemical stability and strongly stimulus-responsive characteristics. By functionalizing ionic liquids themselves or incorporating ionic liquids into traditional materials, many new kinds of stimuli-responsive materials have been developed. In this chapter, we specifically focus on the recent advances in electro-responsive electrorheological smart fluids with ionic liquids and polymeric ionic liquids as either active components or additives. The goal is to highlight the potential of incorporating ionic liquids into traditional electrorheological materials and using polymeric ionic liquids as new electrorheological active materials to overcome the problems of present electrorheological fluids for real applications.

Energy storage systems have aroused public interest because of the blooming development of intermittent renewable energy sources. Vanadium redox flow batteries (VRFBs) are the typical candidates owing to their flexible operation and good cycle durability. However, due to the usage of perfluorinated separator membranes, VRFBs suffer from both high cost and serious vanadium ions cross penetration. Herein, we fabricate a series of low-budget and high-performance blend membranes from polyvinylpyrrolidone (PVP) and cardo-poly(etherketone) (PEKC) for VFRB. A PEKC network gives the membrane excellent mechanical rigidity, while PVP endows the blend membranes with superior sulfonic acid uptake owing to the present N-heterocycle and carbonyl group in PVP, resulting in low area resistance. Meanwhile, blend membranes also display low vanadium ion permeability resulting from the electrostatic repulsion effect of protonated PVP polymer chains towards vanadium ions. Consequently, the 50%PVP-PEKC membrane has a high ionic selectivity of 1.03 × 106 S min cm−3, while that of Nafion 115 is nearly 17 times lower (6.03 × 104 S min cm−3). The VRFB equipped with 50%PVP-PEKC membrane has high coulombic efficiencies (99.3–99.7%), voltage efficiencies (84.6–67.0%) and energy efficiencies (83.9–66.8%) at current densities of 80–180 mA cm−2, and possesses excellent cycle constancy, indicating that low-cost x%PVP-PEKC blend membranes have a great application potentiality for VRFBs.

The aim of this study was to develop ionic liquid (IL) polymer materials incorporating enzymes that can be used as active, stable and reusable biocatalysts. To this goal, Candida rugosa lipase has been microencapsulated in surfactant aggregates formed in an IL monomer or the solution of an IL monomer/IL and then incorporated into polymer frameworks through the free radical polymerization of an IL (1-vinyl-3-ethylimidazolium bis(trifluoromethyl-sulfonyl) amide) ([veim][Tf(2)N]). The activity, stability and reusability of such IL polymer materials containing lipase were evaluated using lipase-catalyzed hydrolysis of p-nitrophenyl butyrate (p-PNB) as a model reaction. Lipase encapsulated within ionic liquid polymer materials remained active and exhibited excellent stability in aqueous solutions. More importantly, these biopolymer materials retained most of their activity after five reaction cycles, in which biopolymers were recovered from the reaction mixture simply by centrifugation. This study promulgates a direction toward the design of IL - an interesting class of tunable and designable solvents - based polymer materials containing biomolecules via a combination of polymer and supramolecular chemistry for diverse applications.

Novel sulfonated poly(ether ether ketone)/oxidized g-C3N4 composite membrane for vanadium redox flow battery applications

We performed long-time all-atom molecular dynamics simulations of cationic polymerized ionic liquids with eight mobile counterions, systematically varying size and shape to probe their influence on the decoupling of conductivity from polymer segmental dynamics. We demonstrated rigorous identification of the dilatometric glass-transition temperature (Tg) for polymerized ionic liquids using an all-atom force field. Polymer segmental relaxation rates are presumed to be consistent for different materials at the same glass-transition-normalized temperature (Tg/T), allowing us to extract a relative order of decoupling by examining conductivity at the same Tg/T. Size, or ionic volume, cannot fully explain decoupling trends, but within certain geometric and chemical-specific classes, small ions generally show a higher degree of decoupling. This size effect is not universal and appears to be overcome when structural results reveal substantial coordination delocalization. We also reveal a universal inverse correlation between ion-association structural relaxation time and absolute conductivity for these polymerized ionic liquids, supporting the ion-hopping interpretation of ion mobility in polymerized ionic liquids.

Enhanced electrorheological effectiveness and temperature effect of suspensions based on poly(ionic liquid)s neutralized with mixed counterions

Analysis of beer volatiles by polymeric imidazolium-solid phase microextraction coatings: Synthesis and characterization of polymeric imidazolium ionic liquids

Synthesis and properties of polymerized ionic liquids

Polymerized ionic liquids (PolyILs) are a novel class of functional polymers that combine the unique physicochemical properties of molecular ionic liquids with the outstanding mechanical characteristics of polymers [1,2]. This special mix of features might help to circumvent the key limitations of low molecular weight ionic liquids, namely, leakage and poor mechanical properties while utilizing their outstanding characteristics such as low vapor pressures, wide liquidus ranges, high thermal stability, high ionic conductivity, and wide electrochemical windows. PolyILs have shown remarkable advantages when employed in electrochemical devices such as dye-sensitized solar cells, lithium batteries, actuators, field-effect transistors, light emitting electrochemical cells, and electrochromic devices, among others. Despite their promising prospects as ideal polymer electrolytes, the role of molecular structure, morphology, and polymer dynamics on charge transport in PolyILs remains poorly understood. According to classical theories, the self-diffusion and ion transport in electrolytes are controlled by structural relaxation. These approaches predict similar temperature dependence for the dc conductivity and structural dynamics. Although this prediction has been shown to hold reasonably well for low molecular weight aprotic ionic liquids, it fails for PolyILs [2,3]. In addition, the impact of morphology charge transport is not considered within the framework of these theories. The first part of this talk will focus on new insights obtained from experimental studies employing broadband dielectric spectroscopy, temperature-modulated differential scanning calorimetry, rheology, and scattering techniques to elucidate charge transport and structural dynamics in a systematic series of bulk polymerized ammonium- and imidazolium- based ionic liquids. Detailed analyses reveal strong decoupling of these processes in the PolyILs, implying the limitation of the classical theories in describing charge transport and molecular dynamics in these materials, in contrast to low molecular weight systems (4,5). In addition, the strong correlation observed between ionic conductivity from dielectric experiments and morphologies from scattering studies will be reviewed. In the second part of this talk, our recent results from a new approach to dielectric experiments yielding details about ion dynamics in ultrathin films of polymerized ionic liquids down to sub-5nm film thicknesses will be discussed. While the characteristic charge transport rates remain bulk-like down to about 5 nm film thicknesses, ionic-liquid/substrate interactions play an increasingly significant role in determining ion dynamics in confined polymerized ionic liquids (5). These results will be considered within the context of recent models of charge transport and polymer dynamics under confinement. References 1) Mecerreyes, D. Progress in Polymer Science 2011, 36, 1629. 2) Sangoro, J. R. and Kremer, F. Accounts of Chemical Research 2012, 45, 525 3) Sangoro, J. R. et al., Soft Matter 2014, 10, 3536. 4) Wojnarowska, Z. et al., Macromolecules 2015, 48 (23), 8660-8666. 5) Heres, M. F. et al., Submitted.

Preparation of cellulose-polymerized ionic liquid composite by in-situ polymerization of polymerizable ionic liquid in cellulose-dissolving solution

Polymeric ionic liquid enhanced all-solid-state electrolyte membrane for high-performance lithium-ion batteries

A set of new experimental data was obtained regarding the influence of the structure of dimer ionene ionic liquids on their physical and chemical properties, which is the basis of the methodology for the synthesis of polymer ionene ionic liquids. It was established that the introduction of allyl and -hydroxyethyl groups into the quaternary nitrogen atom, the presence of a dibenzyl fragment at the cationic center and alkylaromatic radicals permit obtaining polymeric ionic liquids of the ionene type with a high level of ionic conductivity at a low glass transition temperature. Newly synthesized polymeric ionic liquids and ionene ionic liquids based on 1,2-epoxy-4,7-dioxononen-8 and tetrahydro-1,4-oxazine derivatives with an ionic conductivity of ~10–1–10–4 S cm–1 with glass transition temperature range of –1400С to –160С exhibited five to six orders of magnitude higher ionic conductivity as compared with known analogues. Recommendations for solving the problem of developing polymeric ionic liquids and ionene ionic liquids exhibiting high ionic conductivity while maintaining their liquid state in a wide temperature range have been developed.

As a polymer host, one polymeric ionic liquid poly(methyl methacrylate-1-vinyl-3-ethyl-imidazolium bis(trifluoromethylsulfonyl) imide) (abbr. P(MMA-co-VEImTFSI)) was successfully synthesized and characterized. Four poly(vinylidene fluoride-co-hexafluoropropylene) (abbr. PVDF-HFP)-based polymer electrolytes were prepared by blending 0, 5,15, and 25 wt% P(MMA-co-VEImTFSI). The electrochemical performances of the prepared electrolytes were studied carefully. The results revealed that increasing the polymeric ionic liquid content, the ionic conductivity of the polymer electrolytes could be enhanced and it obeyed the Arrhenius rule. The highest ionic conductivity of the polymer electrolytes was up to 2.09 × 10−3 S cm−1 at room temperature. The polymer with 25 wt% polymeric ionic liquid showed an excellent electrochemical performance for supercapacitor electrolyte. After 2000 cycles, the retention of capacitance in P(MMA-co-VEImTFSI)-based polymer electrolyte was above 80%. It implied that the present P(MMA-co-VEImTFSI) polymeric ionic liquid was a decent component candidate in the high-performance polymer electrolytes.