Search

Palladium nanoparticles stabilised by aniline modified polymer immobilised ionic liquid is a remarkably active catalyst for the hydrogenation of CO2 to formate; the initial TOF of 500 h−1 is markedly higher than either unmodified catalyst or its benzylamine and N,N-dimethylaniline modified counterparts and is among the highest to be reported for a PdNP-based catalyst. [ABSTRACT FROM AUTHOR]

Developing a simple and efficient heterogeneous catalyst for the cycloaddition of epoxides with CO2 under atmospheric pressure and cocatalyst-/metal-/solvent-free conditions remains a great challenge. Herein, poly(ionic liquid)s (P-[VRIm]Br-crosslinker-x) with unique adsorption-swelling ability toward epoxides are designed and facilely synthesized via free radical polymerization in water. The adsorption-swelling of epoxides by P-[VRIm]Br-crosslinker-x is controllable, reversible, and widespread, resulting from the strong interactions between the poly(ionic liquid)s and epoxide molecules, especially the hydrogenbonding interaction. Superior CO2 cycloaddition is realized in the P-[VRIm]Br-crosslinker-x catalyst through the adsorption-swelling effect. Specifically, P-[VC6Im]Br-C8-5% with 54.1 mmol g-1 adsorptionswelling ability toward styrene oxide achieves 89.3% yield and >99% selectivity in the cycloaddition of styrene oxide with CO2 to styrene carbonate under mild conditions (1 atm, 80 °C) without cocatalyst/metal/solvent consumption. Moreover, P-[VC6Im]Br-C8-5% can be easily recovered by deswelling, and shows good reusability and stability after five cycles for a total of 180 h. The adsorption-swelling property of P-[VRIm]Br-crosslinker-x to epoxides not only prompts the active centers to be fully exposed to the reactants but also induces the enrichment of epoxides during the whole catalytic process, thus accelerating the CO2 cycloaddition reaction rate. This work furnishes new insights for improving the activity of CO2 cycloaddition and would guide the design of efficient poly(ionic liquid) catalysts for atmospheric CO2 conversion. [ABSTRACT FROM AUTHOR]

In recent years, chemical recycling to monomer (CRM) has emerged as an advanced strategy to deal with post-consumer plastics. However, because it usually takes a long time to react at a relatively high temperature, CRM suffers from side reactions and energy consumption issues. In this work, a Brønsted–Lewis acid ionic liquid/polyhydroxy-compound system ([Et3NH][ZnCl3]/pentaerythritol) was developed as a bifunctional reagent for dissolving poly(p-dioxanone) (PPDO) and highly efficiently catalysing its CRM. In situ addition of the polyhydroxy-compound significantly prevented the formation of byproduct, i.e., cyclic PPDO, by converting it back to depolymerizable linear PPDO. Therefore, both the CRM efficiency and selectivity were obviously improved. At 160 °C, PPDO was almost fully depolymerized to the PDO monomer in only 8 minutes with 99.9% GC purity of yield. Moreover, [Et3NH][ZnCl3]/pentaerythritol could be reused at least 5 times without post-processing and its chemical structure and efficiency remained intact. According to the kinetic study, the activation energy of depolymerization was calculated to be 64.81 kJ mol−1, half lower than the traditional method. Based on NMR titration, the catalytic mechanism was discussed. Importantly, according to the assessment of the energy economy factor, environmental factor, and environmental energy impact factor, the strategy developed in this work is better than all of the related works in greenness. [ABSTRACT FROM AUTHOR]

The conversion of CO2 into value-added chemicals has become an imminent research topic and the cycloaddition of CO2 with a C1 resource to produce cyclic carbonates is a promising pathway for CO2 utilization. Herein, a series of POSS-based polyionic liquids (PILs) were synthesized by the copolymerization of octavinyl polyhedral oligomeric silsesquioxane (POSS) with an imidazolium ion linker. The prepared PILs have the characteristics of hydrogen bond donors, halogen atom sites, stable pore structures, and thermal stability, and are used as heterogeneous catalysts for the cycloaddition of epoxides with carbon dioxide. The effect of linkers on the cycloaddition is investigated by tuning the ratio of POSS units to imidazolium ions. Under the optimized conditions, the conversion of epichlorohydrin can reach 99.18% at atmospheric pressure with neither co-catalysts nor solvents. It is concluded that the reaction of the cycloaddition of epoxides with carbon dioxide follows pseudo-first-order kinetics. Moreover, the presence of the catalysis of PILs leads to a significant decrease in the activation energy barrier for cycloaddition. The catalyst can be facilely recovered due to its high stability, and only a slight decrease in conversion was observed after five successive runs. In addition, the mechanism of PILs catalyzing the cycloaddition reaction of epoxides with CO2 is proposed. This work not only provides a sustainable and green process for CO2 cycloaddition, but also highlights the potential of using PILs for CO2 utilization. [ABSTRACT FROM AUTHOR]

Pertechnetate (TcO4−) poses long-term potential radioactive hazards to the ecological environment, so it is an urgent challenge to selectively separate TcO4− from radioactive wastewater. In this work, we firstly developed a series of binary ionic liquid functionalized silica (SiO2-g-PC2-CnvimBr) by simultaneous radiation grafting of the hydrophilic ionic liquid 1-vinyl-3-ethylimidazole bromide ([C2VIm]Br) and hydrophobic ionic liquid 1-vinyl-3-alkylimidazolium ([CnVIm]Br, n = 4, 6, 8, and 12) onto silica for the removal of ReO4− as an analogue of TcO4−; single ionic liquid functionalized silica (SiO2-g-PC2vimBr) was also synthesized for comparison. The effects of absorbed dose and RAFT agent content on grafting yield were investigated. The grafting yield (GY) increased with increasing absorbed dose and decreasing RAFT agent content. SiO2-g-PC2-CnvimBr showed excellent acid and irradiation resistance; the adsorption efficiency was still more than 90% after soaking in acid solution for 3 months or after being irradiated at 1000 kGy. SiO2-g-PC2-CnvimBr presented superior selectivity for ReO4− over SiO2-g-PC2vimBr. Furthermore, the continuous uptake of ReO4− using SiO2-g-PC2-CnvimBr with varying alkyl chain lengths of hydrophobic imidazolium was investigated and compared in the simulated radioactive wastewater. It was found that the relative column adsorption capacity and selectivity increased with increasing alkyl chain length of hydrophobic imidazolium. In addition, SiO2-g-PC2-C8vimBr displayed excellent reusability; the adsorption capacity did not change and the desorption efficiency could reach 97% in the flow-through column cycle experiment. On the basis of experimental results, SiO2-g-PC2-CnvimBr was deemed to be promising for continuous separation of TcO4−/ReO4− in the practical treatment of radioactive wastewater and TcO4− contaminated groundwater. [ABSTRACT FROM AUTHOR]

Alkali-resistant metal-based cationic polyelectrolytes are designed as anion exchange membranes. After grafting aminocobaltocene hexafluorophosphates onto partially fluorinated ether-free poly(arylene–alkane)s via a simple nucleophilic substitution reaction, the membrane exhibits excellent chemical, thermal and mechanical stability, high hydroxide conductivity, as well as durability of single cells for 400 h. [ABSTRACT FROM AUTHOR]

Bilayered sodium dodecyl sulfate (SDS)/ionic liquids (alkyl imidazolium type ionic liquid Cnmim+, n = 10, 12, 14, and 16) were first employed to modify the surface of Fe3O4 nanoparticles for the formation of stable aqueous ferrofluids. Subsequently, in the synthesized bilayered SDS/C16mim+-stabilized ferrofluid (Fe3O4/SDS/C16mim+), magnetic mesoporous silica with a cubic (Ia3d) mesostructure (Fe3O4@MCM-48) has been synthesized using tetraethylorthosilicate as the silicon source and the long chain C16mim+ as a template again. The research results showed that the combination of SDS and long chain Cnmim+ (such as C16mim+) is superior to that of SDS and short chain Cnmim+ (such as C10mim+) for the production of stable ferrofluids in water. Moreover, Fe3O4@MCM-48 (0.1 g) with Fe3O4 particles embedded in the network of cubic mesoporous silica showed decolorization rates of up to ∼90% in 25 min for four dye (methylene blue, rhodamine B, malachite green, and methyl violet) solutions (50 mL, 100 mg L−1). In addition, the malachite green-adsorbed Fe3O4@MCM-48 can be separated and recovered under an external magnetic field. This method in which the long chain ionic liquid C16mim+ can be manipulated in turn not only as the modifier but also as the mesoporous templating agent provides important guidelines for the multifunctional applications of C16mim+ in the synthesis of various nanostructured materials. [ABSTRACT FROM AUTHOR]

It is of great significance to efficiently synthesize compounds with pharmacological activities through CO2 conversion. Herein, polyionic liquids (PILs) with adjustable structures and multiple active sites were synthesized. With epoxy nucleoside as a solid substrate, cycloaddition and carbonate hydrolysis were carried out under the catalysis of polyionic liquid and the participation of CO2 and water. The amphiphilicity of P1, the adjustability of alkalinity and the regulation of the phase state in the presence of water played an important role in the high selectivity and high yield of the reaction. More importantly, the catalyst can be recycled 6 times to maintain high catalytic activity and selectivity. This work successfully provides a solvent-free, metal-free and recyclable green synthetic path for chiral drugs, which will further promote the highly efficient conversion and utilization of CO2. [ABSTRACT FROM AUTHOR]

Chemical carbon dioxide (CO2) fixation via cycloaddition with high energy three-membered ring compounds such as epoxides is among the most promising pathways to reduce the greenhouse gas emission and achieve the utilization of CO2 as an abundant C1 resource, favoring the alleviation of the global energy and environmental issues. A great number of catalysts have been developed, while heterogeneous ones are preferred due to the facile product separation and catalyst recycling. Among them, porous poly (ionic liquid)s (PILs) combining the advantages of porous materials, polymers and ionic liquids (ILs; for simplification, in this review, ILs comprise these traditional room temperature ILs and their derivatives) have exhibited great potential in CO2 fixation via cycloaddition. This review systematically summarizes the recent progress in the one-pot synthesis and post-synthesis of porous PIL catalysts for CO2 cycloadditions. The former covers the free-radical homopolymerization of ILs, free radical co-polymerization of ILs and linkers, quaternization reaction, Friedel-Crafts alkylation reaction, and several polycondensations via Schiff base chemistry, phenol-formaldehyde condensation reaction, click reaction, Heck and Zincke reaction, Sonogashira coupling reaction, trimerization reaction, and urea-forming condensation reaction. Post-synthesis of porous PILs mainly relies on the immobilization of ILs on a porous polymer support. One-pot synthesis is advantageous in the molecular level design and construction of porous PILs with large surface areas and high density of ionic moieties with homogeneous distribution, providing highly effective catalysts for CO2 cycloaddition under mild conditions. The details of the synthesis of porous PILs and the catalytic behavior in CO2 cycloaddition with epoxides are summarized, and it is emphasized that the rational design of IL monomers and optimization of synthetic parameters to control the structural characteristics and chemical compositions of porous PILs are crucial to the fabrication of high-performance catalysts. Finally, we pointed out that great efforts are still needed towards advanced porous PILs for CO2 cycloaddition to increase the activity, stability and scope. Besides, the cost of porous PILs should be lowered to adapt to industrial applications. [ABSTRACT FROM AUTHOR]

Poly(ionic liquid)s (PILs) have gained widespread attention in recent years due to their excellent properties similar to both ionic liquids and polymers. However, their further applications are limited because abundant and flexible ions easily block nanopores in the PIL catalysts, thus blocking the active sites and ultimately leading to decreased catalytic activity. This work reports the synthesis of a PIL/graphene composite catalyst (iPOP-ZnTPy@GNFs) based on an in situ surface preparation strategy, which effectively controlled the particle size and dispersion state of ionic liquids. The iPOP-ZnTPy@GNFs exhibited a larger surface area and more exposed active sites, which intensified the catalytic activity in the CO2 cycloaddition reaction with propylene oxide with almost double the reaction rate as compared to that of iPOP-ZnTPy-2 at 100 °C and S/C = 1000. As expected, the iPOP-ZnTPy@GNF catalyst efficiently converted epoxides to cyclic carbonates at room temperature or atmospheric pressure, which can significantly reduce the process cost. In addition, iPOP-ZnTPy@GNFs exhibited excellent broad substrate scope, catalytic diversity, and remarkable reusability. The reaction mechanism of CO2 cycloaddition was studied via density functional theory calculations and was validated by experimental findings. This work provides a feasible method for improving the utilization of active sites in PILs as a highly robust catalyst for CO2 cycloaddition and can be further extended to other types of catalytic reactions in practical applications. [ABSTRACT FROM AUTHOR]

γ-phase copper(I) iodide (abbreviated to CuI hereafter) with different morphologies is realized through a one-step redox process from I-containing ionic liquid (IL) or poly(ionic liquid)s (PILs) precursors at room temperature. The phase composition, morphology, and electronic states of the synthesized CuI samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The resulting CuI products exhibit three different types of morphologies, namely nanocrystals, with an average size of 0.8 ± 0.2 μm, nanoplates, with a thickness of 35.8 ± 0.9 nm, and nanoflowers, with petals with a thickness of 12.2 ± 0.8 nm. Moreover, the as-synthesized CuI samples exhibit gradually diminishing bandgaps and improved photocatalysis performance for the photodegradation of rhodamine B (RhB) under visible light irradiation as the thickness decreases. XPS measurements confirm that IL/PILs coupled to the CuI surface, resulting in a further charge transfer between Cu and I. These results conclusively prove that IL/PILs serve as both the reducing agents and assemble as orientation templates in the formation of the CuI nanostructures, and also successfully mediate the functional properties of the samples by changing the surface electronic structures. [ABSTRACT FROM AUTHOR]

The multi-step reaction of CO2 over basic catalysts significantly improves the diversity of products, vividly embodying the ability of green chemistry to turn waste into treasure. However, under a Lewis acidic CO2 atmosphere, the activity maintenance of the multi-step reaction puts forward higher requirements for the reversible regeneration ability of the basic catalysts. Novel Lewis–Brønsted binary basic poly(ionic liquid)s (LB-PILs) were successfully developed through a radical copolymerization followed by ion-exchange strategy, and were applied to the two-step synthesis of dimethyl carbonate (DMC) by coupling CO2 cycloaddition and CH3OH transesterification without any cocatalyst. Relying on the activation of CO2 by Lewis basic tertiary N and the thermal recovery of nucleophilic HCO3− to stronger Brønsted basic OH− with the help of temperature control in CH3OH transesterification, the LB-PILs presented high activity, stable repeatability and linear carbonate universality. In situ IR analysis and Knoevenagel condensation, combined with theoretical calculations, provided reliable support for the ingenious incorporation of reversible regeneration of basic catalysts in a Lewis acidic CO2 atmosphere and multi-step coupling reaction process of CO2. [ABSTRACT FROM AUTHOR]

CO2 is the most influential greenhouse gas with drastic effects all over the world. Meanwhile, global warming is considered a hot topic to different groups of scientists dealing with the global warming phenomenon. As an alternative to the typically-used scrubbing agent that is heavily used in post-combustion capture technology, namely, monoethanolamine, with its well-known drawbacks, the ionic liquids (ILs) and their corresponding polymers, viz., poly(ionic liquid)s (PILs) have been exploited. In this study, we constructed new imidazolium-based PILs with high surface area fabricated from a 3-(3-(phthalimide)propyl)-1-vinylimidazolium bromide IL-precursor with N-allylphthalimide building blocks, in the presence of divinylbenzene serving as a cross-linker, through a free-radical polymerisation process, and provide their ability for the dual purposes of CO2 capture and utilisation. In this context, the chemical structure of the monomers was fully characterised using elemental analysis, nuclear magnetic resonance and attenuated total reflectance-infrared spectroscopy. The polymeric materials were further examined by thermogravimetric analysis, the Brunauer–Emmett–Teller model and scanning electron microscopy. The sorption characteristics of the amine functionalised PILs were measured volumetrically with CO2 uptake values up to 0.59 mmol CO2 per g sorbent under RTP conditions (25 °C and 1 bar). For CO2 utilisation purposes, the molar ratio of the ionic residues within the polymeric scaffold was increased ranging from one- and two- up to four-fold (×1, ×2, ×4), respectively. Remarkably, the polymeric materials showed excellent catalytic activity for the cycloaddition of CO2 with epoxides to synthesise cyclic carbonates with almost quantitative conversion at 10 bar CO2 and 110 °C. [ABSTRACT FROM AUTHOR]

Porous carbon materials have attracted enormous interest and are widely applied in renewable energy storage and conversion. In this work, freestanding nitrogen/sulfur co-doped porous carbon (NSPC) membranes were fabricated facilely by carbonizing the electrostatically cross-linked complexes, composed of hydrophobic poly(ionic liquid) (PIL) and alginic acid (AA). The newly-fabricated NSPC membranes can be used directly as the electrodes for the electrocatalytic hydrogen evolution reaction (HER) and supercapacitors in the absence of any binding agents/additives. Outstandingly, NSPC-9 presented a specific capacitance (Cs) as high as 969 F g−1 at the current density of 0.1 A g−1. Additionally, NSPC-9 also delivered excellent HER electrocatalytic performance. In particular, a current density of 10 mA cm−1 could be achieved at a low overpotential of 146 mV, and a small Tafel slope of 64 mV dec−1 could be presented. Benefiting from their large surface area, moderate N/S dopants and good electron/electrolyte transport ability, as well as low cost and convenient synthesis procedure, NSPCs are promising electrode materials and have great potential applications in electrocatalysis and supercapacitors. [ABSTRACT FROM AUTHOR]

High-entropy crystalline materials are attracting more attention. In principle, high-entropy metal carbides (HMCs) that contain five or more metal ions, possess more negative free energy value during catalysis. But its preparation is challenging because of the immiscibility of multi metal cations in a single carbide solid solution. Here, a rational strategy for preparing HMC is proposed via a coordination-assisted crystallization process in the presence of Br-based poly(ionic liquids). Through this method, Mo0.2W0.2V0.2Cr0.2Nb0.2C nanoparticles, with a single cubic phase structure, incorporated on porous carbon, are obtained (HMC@NC). By combination of well dispersed small particle size (∼4 nm), high surface area (∼270 m2 g−1), and high-entropy phase, HMC@NC can function as a promising catalyst for the dehydrogenation of ethylbenzene. Unexpected activity (EB conv.: 73%) and thermal stability (>100 h on steam) at 450 °C are observed. Such a facile synthetic strategy may inspire the fabrication of other types of HMCs for more specific tasks. [ABSTRACT FROM AUTHOR]

The design of novel ionic liquid monomers with attractive properties represents a real challenge in the field of poly(ionic liquid)s (PILs). Here, we describe a comparative study of the synthesis of original PIL precursors from various sulfonimides or ketosulfonamides as unprecedented counteranions of imidazolium ILs. These salts were submitted to the Prilezhaev reaction and a first insight into the intrinsic properties of these new epoxy monomers was unveiled, in particular the thermal stability of these advanced epoxy salts by comparison with traditional counterions. [ABSTRACT FROM AUTHOR]

We report the synthesis and structure/property correlations of a series of eight poly(ionic liquid)s (PILs) obtained from sequential AA + BB polyaddition by copper(I)-catalyzed azide–alkyne cycloaddition and the subsequent N-alkylation reaction. The different repeat units contain one to four ion pairs, with one to four bis(trifluorosulfonyl)imide (TFSI) anions and one or two types of ammonium, imidazolium or 1,2,3-triazolium counter-cations. Their physical, ion conducting and electrochemical properties are discussed based on the repeat unit charge density and structure of the cationic moieties. The comparison of several pairs of polyelectrolytes revealed that ionic conductivity is dependent on (1) the ratio between the number of charge carriers per monomer unit and the number of surrounding atoms/groups that can solvate the ions and (2) the nature of the cation. The highest conductivity (1.8 × 10−5 S cm−1 at 25 °C) was reached when PILs contain two 1,2,3-triazolium cations that are separated by an oxyethylene spacer. The incorporation of an additional type of cation (either imidazolium or ammonium with 1,2,3-triazolium) in one PIL allows its cathodic limit to be increased up to −0.4 V vs. Li+/Li (70 °C) and the oxidation instability of 1,2,3-triazolium cations to be overcome. [ABSTRACT FROM AUTHOR]

A polymer gel electrolyte (PGE), using poly(styrene-co-acrylonitrile) (SAN) as a gelator, 1-butyl-3-methylimidazolium iodide (BMIMI) as the ionic liquid, and lithium iodide (LiI) as a source of iodide ions, is synthesized and investigated for its performance while employing it in a quasi-solid-state dye-sensitized solar cell using a N719 sensitizer and an I−/I3− redox couple. The PGEs are synthesized using different wt% of SAN and the relative amounts of LiI and I2 are optimized for iodide ion (I−) and triiodide ion (I3−) generation and their influence on the photovoltaic performance of the devices was investigated. On optimizing the PGE composition, the device gives an ionic conductivity of 7.00 mS cm−1, with a triiodide diffusion coefficient of 7.28 × 10−5 cm2 s−1, ensuring efficient polymer networks for the mobility of ionic species. The absorption edge for all PGEs lies close to ∼420 nm having transparency of more than 80% in the visible and NIR region. Impedance analysis evidently supports 17 wt% SAN as the optimum composition for PGE with better charge transfer and a decrease in recombination rate and considerable improvement in the electron lifetime. The highest photovoltaic conversion efficiency is 6.72% with the 17 wt% SAN PGE. [ABSTRACT FROM AUTHOR]

The synthesis of a novel poly(ionic liquid) adsorbent (PIL-APIBCl) through the modification of poly(styrene-co-maleic anhydride) (PSMA) composites with N-(3-aminopropyl)imidazole (API) and benzyl chloride (BCl) is presented. The structural analysis was carried out by nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FT-IR). Batch adsorption experiments revealed that the investigated adsorbent exhibited good selectivity and a high adsorption capacity of 236.68 mg g−1 towards tetrachloroaurate (Au(III)) ions at pH 1.0 over a wide temperature range. The adsorption isotherms and kinetics of Au(III) on the PIL-APIBCl were fitted well by the Langmuir isotherm model and pseudo-second-order model, respectively, indicating successful chemical adsorption of Au(III) ions on the adsorbent surfaces. According to FESEM, FT-IR, XPS and NMR analysis, the adsorption mechanisms of Au(III) on PIL-APIBCl could be ascribed to electrostatic and intermolecular interactions. Therefore, due to its good cyclability and low cost, PIL-APIBCl is a promising adsorbent for Au(III) recovery from wastewater on a large scale. [ABSTRACT FROM AUTHOR]

The syntheses and full spectral (NMR, MS, and IR), thermal (DSC) and ion chromatographic characterization of two series of amine-derived ionic liquids bearing allyl substituents and having chloride or bis(trifluoromethanesulfonyl)amide anions have been presented. The analysis of the dependence of the 1H NMR chemical shift values of the selected protons on the cation and anion structure has been conducted. DSC analysis records together with ion chromatography analysis results have been presented and interpreted. Moreover, a selection of obtained chloride ionic liquids have been transformed into the corresponding chlorocobaltates and chlorozincates or used as substrates in thiol–ene click reactions to indicate their potential as precursors of catalysts or various surface modifiers. [ABSTRACT FROM AUTHOR]

An alternating copolymer-based poly(ionic liquid) (PIL) was synthesized and blended with PVDF-HFP to obtain solid-state polymer electrolytes with both high mechanical strength and high ionic conductivity. Structural analysis reveals that the high performance is attributed to the nanophase separation of PVDF-HFP with a PIL in the nanometric scale, which benefits from an alternating polymer architecture of the PIL. [ABSTRACT FROM AUTHOR]

Poly(ionic liquid)s (PILs), as an innovative class of polyelectrolytes, are composed of polymeric backbones with IL species in each repeating unit. The combined merits of the polymers and ILs make them promising materials for composites in materials science. Particularly, the integration of PILs with functional substances (PIL composites) opens up a new dimension in utilizing ionic polymers by offering novel properties and improved functions, which impacts multiple subfields of our chemical society. This review summarizes recent developments of PIL composites with a special emphasis on the preparation techniques that are based on the intrinsic properties of the PILs and the synergistic effects between the PILs and substances of interest for diverse applications. [ABSTRACT FROM AUTHOR]

Lamellar MoS2 nanosheets were successfully prepared by hydrothermal synthesis using 1-(3-mercaptopropyl)-3-methyl-imidazolium bromine (MIMBr) ionic liquid as a sulfur source and a morphology control agent, and sodium molybdate as a molybdenum source. Gold nanoparticles were assembled on the surface of MoS2 nanosheets by the in situ reduction of chloroauric acid at low temperatures to successfully fabricate AuNP/2D-MoS2 nanocomposites, thus improving photoelectrochemical response. AuNP/2D-MoS2 nanocomposites were used as photoelectrically active materials modified onto a glassy carbon electrode surface to construct a photoelectrochemical (PEC) sensor. Then, using 1-(N-pyrrolpropyl)-3-methyl-imidazolium bromine (PMIMBr) ionic liquid as a functional monomer and pro-gastrin-releasing peptide (Pro-GRP) as a template, a molecularly imprinted polymerized ionic liquid film was electrochemically deposited on an AuNP/2D-MoS2/GCE surface. Upon removing the templates, a molecularly imprinted photoelectrochemical sensor was constructed for the sensing of a tumor marker, pro-gastrin-releasing peptide. Experimental conditions including ascorbic acid concentration, polymerization conditions, incubation time, and pH value of the incubation solution have been optimized. Under the optimized conditions, the molecularly imprinted photoelectrochemical sensor can specifically detect the target protein Pro-GRP in the range of 0.02 ng mL−1–5 ng mL−1 with a detection limit of 0.0032 ng mL−1 (S/N = 3). The practicability of this photoelectrochemical sensor was demonstrated by accurately determining Pro-GRP in human serum samples. [ABSTRACT FROM AUTHOR]

Thermoregulated phase separable catalysis (TPSC) in its current state involves small organic ligands that coordinate with CuBr2 to form ligand–catalyst complexes that are easily lost during recycling and reuse. Introducing copolymer poly(ionic liquids) (PILs) into TPSC systems appears to be a promising strategy to solve this problem owing to their relatively large sizes. Herein, a thermoregulated substituted random tricopolymer poly(ionic liquid) macroligand (PILLL) with pendant side chains of an ATRP ligand, poly(ethylene glycol) (PEG) and alkylammonium ionic liquid was designed and synthesized in a facile fashion. The macroligand coordinated with CuBr2 to generate a macroligand–catalyst complex (PILLL/CuBr2) was applied in TPSC as an initiator for a continuous activator regeneration (ICAR) ATRP system. This newly constructed TPSC system was endowed with the advantages of in situ separation of polymers coupled with the simultaneous recycling of both the macroligand and transition metal catalyst by modulating the temperature of the polymerization process from 25 °C to 70 °C and reversing it to 25 °C. Furthermore, after performing ten recycling experiments, the catalytic recycling efficiency was still relatively high (>95%) with narrow molecular weight distributions (Mw/Mn ≤ 1.31), while the residual transition metal in the polymeric solution was lower than 2.4 ppm. [ABSTRACT FROM AUTHOR]

A highly lipophilic ionic liquid (IL) consisting of stoichiometrically equal amounts of two purely functional chemical sensing molecules, an anionic calcium ionophore and a cationic dye, was synthesized for the first time, and used as a component for a poly(vinyl chloride)-based or neat liquid membrane optical sensor. This is the first report of an IL consisting of purely functional chemical sensing molecules, which is completely different from the previously reported ionic liquids typically consisting of imidazolium or other lipophilic cations. Since the present IL contained an extremely high concentration of dyes, the IL-based sensor showed dramatically enhanced sensitivity (13 times higher compared to that of a conventional sensor), and fully reversible and selective response to Ca2+. Preliminary investigation on the unique response characteristics of the present liquid membrane IL-based sensor was performed with the responses to Ca2+ and Na+. [ABSTRACT FROM AUTHOR]

The piezoelectric properties of poly(vinylidene fluoride) (PVDF) are determined by the prevalence and orientation of its polar β-crystal phase, which can be tuned by processing conditions, additives, mechanical stretching or post-treatment. Here, the effects of three types of processing conditions on the crystalline structure evolution of PVDF were investigated; electrospinning, solution-casting and melt-compression. An ionic liquid (1-allyl-3-methylimidazolium chloride (AMIM)) used as an additive in aiding the electrospinning process, also affected the crystalline structure of the electrospun PVDF nanofibers. The total crystallinity, crystalline phase content and dielectric properties of the PVDF samples prepared by the different conditions were evaluated. The FTIR and DSC analyses show that the melt-compressed PVDF contains a high proportion of the paraelectric α-phase with a low total crystallinity, whereas the solution-cast PVDF contains a high proportion of polar γ-phase and a higher total crystallinity. In the case of the electrospun PVDF nanofibres, the addition of AMIM improved the morphology, uniformity and promoted the formation of the polar β and γ crystalline phases. X-Ray scattering analysis refined the crystal phase contents derived from FTIR, and also determined the ordered lamellar macromorphology formed by the three processing techniques. Furthermore, AMIM enhanced the a.c. conductivity and relative permittivity of the electrospun PVDF nanofibres by an order of magnitude, showing the effectiveness of using the ionic liquid AMIM, to improve the morphology and properties of electrospun PVDF nanofibers. [ABSTRACT FROM AUTHOR]

The therapeutic efficacy of anticancer drug delivery systems is severely truncated by their low tumor target ability and inefficient drug release at the target site. Herein, we report the design and synthesis of a novel dual-responsive hyaluronic acid-grafted poly(ionic liquid) block copolymer that was able to self-assemble into spherical nanoparticles in water. Then, the doxorubicin-loaded block copolymer produced particles of 100 nm in size as examined using transmission electron microscopy and dynamic light scattering. The hyaluronic acid-grafted block copolymer micelles were efficiently taken up by CD44-overexpressing cancer cells as indicated by the cell counting kit-8 assays, confocal laser scanning microscopy, and flow cytometry experiments. Therefore, the as-prepared block copolymer micelles had good biocompatibility, low toxicity, and high selectivity, thus offering promise for the treatment of various CD44-overexpressing cancers. [ABSTRACT FROM AUTHOR]

It is known that some neat room-temperature hydrophobic ionic liquids can extract metallic species from aqueous solutions. The unique properties of such organic media allow for the application of polymerization techniques to convert the liquid organic phase to a solid one. In this work, a pyrrolidinium-based ionic liquid and a corresponding polymer with a bis(trifluoromethanesulfonyl)imide counter anion have been considered for optimization of thallium(iii) migration in liquid–liquid and solid–liquid extraction systems. Neither trivalent indium nor monovalent thallium was absorbed by the polymer layer. A mathematical model to describe the mechanism of metal extraction in these systems has been developed. Thermodynamic parameters such as adsorption enthalpy, entropy, and Gibbs energy have also been determined. [ABSTRACT FROM AUTHOR]

To address the issues allied with cardiovascular diseases and the increased prevalence of hypertension, a novel electrochemical sensor was developed based on poly(ionic liquid) [PVIM]–cobalt polyoxometalate (Co5POM) supported on carbonaceous materials (MNCs) for the highly selective and ultrasensitive non-enzymatic detection of cholesterol. The novel composite exhibits excellent selectivity and sensitivity towards the non-enzymatic electrochemical detection of cholesterol with a low detection limit of 1 fM (1 × 10−15 M), a response time of ∼5 s, and a wide detection range of 1 fM–5 mM with two linear ranges of 1 fM–200 nM and 0.5 μM–5 mM with sensitivities of 210 and 64 μA μM−1 cm−2, respectively, even in the presence of ascorbic acid, glucose and uric acid. The proposed sensor was tested with a human blood serum sample at physiological pH in a physiologically relevant concentration range. A novel flexible sensor was developed with PVIM–Co5POM/MNC coated over Whatman filter paper and this shows a high sensitivity with a wide detection range of 1 fM–5 mM. [ABSTRACT FROM AUTHOR]

A new synthetic route towards a bifunctional ionic liquid-bridged organotrichlorotin derivative has been developed. This newly isolated compound acts as an efficient, solvent-free catalyst in the ROP of ε-caprolactone to provide polymers with controlled molecular weights and narrow dispersity (Đ ＜ 1.2). Owing to its easy removal from the medium, ICP-AES analyses showed a lower level of the residual tin catalyst in the resulting polymer compared to the contamination observed in poly(ε-caprolactone) prepared using a commercial catalyst (3 ppm versus 360 ppm). No toxicity was revealed during antibacterial studies on Staphylococcus epidermidis performed on poly(ε-caprolactone) or on a tin supported catalyst, thereby validating the suitability of this route toward manufacturing biologically-relevant materials. [ABSTRACT FROM AUTHOR]

Poly(ionic liquid) (PIL) catalysts with swelling ability and water enrichment ability in water/ethylene carbonate (EC) mixed substrates were designed and synthesized via a one-step direct radical copolymerization of N-vinylimidazolium IL monomers, sodium acrylate and crosslinkers. The structure and morphology of the PILs were characterized by NMR, FT-IR, TGA, SEM and elemental analysis. The effect of substituent groups and crosslinkers on the swelling ability and water enrichment ability of PILs in water and EC was studied. The water enrichment ability of PILs was positively related to the hydrophilicity of 3-substituents on imidazoliums and the crosslinkers, and water could be absorbed inside quantitatively. These PIL catalysts could enrich the optimal ratio of water to EC inside and act as high-efficiency microreactors for the catalytic hydrolysis of EC. The water enrichment ability of PIL microreactors was helpful for the decrease of water amount and the increase of catalytic efficiency. [ABSTRACT FROM AUTHOR]

In this work, a new molecularly imprinted polymer (MIP) using a poly (ionic liquid) (PIL) as a functional monomer was prepared and utilized as the extraction medium of multiple monolithic fiber solid-phase microextraction (MMF-SPME). A PIL, 1-ally-3-vinylimidazolium chloride, was used as a functional monomer, and 3,4-dihydroxybenzenepropanoic acid (DBA) and ethylene dimethacrylate were chosen as the template molecule and cross-linker, respectively, to synthesize the PIL/MIP. Under the optimized preparation conditions, the recognition coefficient of PIL-MIP for DBA was as high as 11.6. The combination of PIL/MIP-MMF-SPME and high-performance liquid chromatography with diode array detection (HPLC/DAD) was developed for the sensitive determination of phenolic acids (PAs) in fruit juice and beer samples. Under the optimal conditions which were investigated in detail, the limits of detection (LODs, S/N = 3) for PAs in fruit juice were 0.024–0.24 μg L−1, and the related values were 0.011–0.052 μg L−1 for the beer sample. The intra-day and inter-day precision (relative standard deviations, n = 4, %) at 1.0 and 100.0 μg L−1 spiking concentration were both less than 10%. In the analysis of PAs in fruit juice and beer samples, satisfactory recoveries and repeatability were achieved. In comparison with reported approaches, the proposed method exhibited some advantages including high selectivity, convenience, satisfactory sensitivity and environmental friendliness. [ABSTRACT FROM AUTHOR]

Solid imidazolium-based polyionic liquids (PILs; a class of polyelectrolyte) were synthesized for the absorption of n-butanol and other inhibitory biosynthesis products from dilute aqueous solutions. Conventional hydrogels prepared by cross-linking water-soluble PILs demonstrated biocompatibility with Saccharomyces cerevisiae, successfully eliminating cytotoxicity concerns associated with the IL monomers. However, the cross-linked PILs’ solute absorption capacity and selectivity for butanol relative to water were below the levels likely needed for a viable extractive fermentation process. Uncross-linked PILs bearing long-chain aliphatic substituents also proved to be biocompatible by virtue of their insolubility in water, and delivered significantly improved absorptive performance. Among biocompatible absorbents, these PILs demonstrated some of the highest absorptions of n-butanol and other hydrophilic fermentation products reported to date, with n-butanol partition coefficient (PC) values up to 7.6 and butanol/water selectivity (αb/w) values up to 78. The influence of linear N-alkyl side chain length (C8 to C16) and counter anions (Cl−, Br−, I−, BF4−, co-SS−) on solute partition coefficient, selectivity and physical properties are detailed and discussed. In all, this work demonstrates that polymerization of cytotoxic ILs can successfully yield biocompatible absorbents with excellent absorptive performance for the recovery of hydrophilic bioproducts. [ABSTRACT FROM AUTHOR]

Here we report a facile and effective strategy for the preparation of ordered mesoporous carbon materials with a high-nitrogen-content (8.1 at%) coating layer through a polymer–ionic liquid assembly strategy. The prepared N-doped mesoporous carbon materials demonstrated enhanced CO2 adsorption capacity (2.29 mmol g−1) compared with non-doped carbon (1.84 mmol g−1). [ABSTRACT FROM AUTHOR]

Hierarchical porous poly(ionic liquid)s (PILs) with high specific surface area were firstly synthesized via anion exchange. The exchange of bulky salicylate and its dimers/clusters in PILs by other smaller anions increased the specific surface area and fabricated a hierarchical porous structure. The high specific surface area and hierarchical porous structure prompted a high degree of exposure of the active sites and made the heterogeneous PIL catalysts contact with substrates sufficiently, enhancing their catalytic activity. [ABSTRACT FROM AUTHOR]

We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments. [ABSTRACT FROM AUTHOR]

Seven Mn(ii) coordination polymers, namely {[Mn2(ptptp)Cl2(H2O)3]·H2O}n (1), {[Mn(μ-ptptp)3]2[Mn3(μ3-Cl)]2}·2Cl·16H2O (2), {[Mn2(ptptp)(ip)2(H2O)3]·H2O}n (3), {[Mn2(ptptp)(5-CH3-ip)2(H2O)3]·H2O}n (4), {[Mn4(ptptp)(5-Br-ip)3(H2O)3]·4H2O}n (5), {[Mn2(ptptp)(Hbtc)(H2O)2]·2H2O}n (6) and {[Mn2(ptptp)(tdc)(H2O)2]·1.5H2O}n (7), have been prepared based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands (H2ptptp = 2-(5-{6-[5-(pyrazin-2-yl)-1H-1,2,4-triazol-3-yl]pyridin-2-yl}-1H-1,2,4-triazol-3-yl)pyrazine; R-isophthalic acids, H2ip-R: R = –H (3), –CH3 (4), –Br (5); H3btc = trimesic acid (6); H2tdc = thiophene-2,5-dicarboxylic acid (7)), in order to further probe the multiple roles of [RMI]Br ionic liquids in the hydro/solvothermal synthesis (RMI = 1-alkyl-3-methylimidazolium, R = ethyl, or propyl, or butyl). The successful syntheses of complexes 2–6 suggest that in hydro/solvothermal synthesis the addition of a small amount of [RMI]Br plays a crucial role. Complex 1 exhibits single right-handed helices constructed by ptptp ligands and Mn(ii) ions. Complex 2 possesses octanuclear helicate structures in which two propeller-shaped [Mn(μ-ptptp)3]4− units embrace two [Mn3(μ3-Cl)]5+ cluster cores inside. Complexes 3 and 4 are isostructural and display a 1D double chain formed by two kinds of pseudo meso-helices: (Mn-ptptp)n and (Mn-5-R-ip)n. Complex 5 has a 2D structure containing 1D Mn(ii) ion chains formed through carboxylates and [ptptp]2−-N,N bridges. Complex 6 shows a 2D structure formed by a meso-helix (Mn-ptptp)n and the partly deprotonated Hbtc ligands. Complex 7 features a heterochiral [2 + 2] coaxially nested double-helical column formed by using the outer double-helices (Mn-ptptp)n as a template to encapsulate the inner double-helices (Mn-tdc)n with opposite orientation. All complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. The magnetic properties of 1–7 were also investigated. [ABSTRACT FROM AUTHOR]

A new heterogeneous catalytic system was prepared by immobilization of tungstate ions on a cross-linked poly(ionic liquid) nanogel. The solid nanogel was easily synthesized by a surfactant-less method. The resulting catalyst was highly active in selective oxidation of sulfides to sulfoxides by H2O2. The oxidation reactions were successfully performed under solvent-free conditions affording high yields. The catalyst was recycled and reused for several reaction cycles without any significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

We report a facile one-step route to graft poly(ionic liquid)s (PILs) onto cellulose nanofibrils (CNFs). The dispersibility of the PIL-functionalized CNFs in water and various organic solvents could be tuned by the choice of the PIL-binding anion. We demonstrate that such omnidispersible PIL@CNF hybrids can be used to reinforce porous poly(ionic liquid) membranes. [ABSTRACT FROM AUTHOR]

The self-assembly of linear polymers containing chiral IL units generates a high-order supramacromolecular structure with a complex hierarchical architecture, which is able to exhibit thermoresponsive behavior (lower critical solution temperature: LCST) with different structural elements that can be used to fine tune this LCST. [ABSTRACT FROM AUTHOR]

Correction for 'An ionic liquid-modified RGO/polyaniline composite for high-performance flexible all-solid-state supercapacitors' by Chang Dong et al., Chem. Commun., 2020, DOI: 10.1039/d0cc04691d. [ABSTRACT FROM AUTHOR]