Ionic Liquid Monomer Research Articles

A Highly Ion‐Conductive Solid Polymer Electrolyte with Good Thermal Stability and Nonflammability for All‐Solid‐State Li Metal Batteries

Lithium metal batteries (LMBs) have been recognized as one of the most promising energy storage devices due to their high energy density. The leakage, corrosion to Li metal anode, and flammability of organic liquid electrolytes bring great security problems for LMBs. Polymeric ionic liquid (PIL)‐based solid polymer electrolytes (SPE), possessing nonflammability, excellent thermal, chemical, electrochemical stability, are a kind of promising SPE for highly safe all‐solid‐state LMBs. Nevertheless, the low ambient conductivity of pristine PIL‐based SPE restricts their application in solid‐state LMBs. Herein, an ionic liquid monomer (denoted as GIM) is designed and synthesized and copolymerized with vinyl ethylene carbonate (VEC) monomer by UV‐light curing to prepare P(GIM‐VEC) SPE. The prepared P(GIM‐VEC) SPE is thermally stable and intrinsically nonflammable, possesses high ambient ionic conductivity, and can suppress lithium dendrite growth and stabilize the solid electrolyte interface. Thus, the resultant all‐solid‐state LiFePO4 (LFP)|P(GIM‐VEC)|Li battery exhibits a high initial discharge capacity of 152.7 mAh g−1 at 0.1 C along with a good stability and rate capability at room temperature. Herein, new guidance is provided for developing ambient workable SPEs with high ionic conductivity, nonflammability, and excellent thermal stability for all‐solid‐state Li metal batteries.

Introduction of versatile and recyclable network poly (ionic liquid)s as an efficient solvent with desired properties for application in C[sbnd]C cross-coupling reactions

Synthesis of high viscosity, ecofriendly, and low melting point poly(ionic liquid)s (LMP-PIL) with network structure has been introduced by the reaction of 1,1′,1′′‑(1,3,5‑triazine‑2,4,6‑triyl) tris(3‑methyl‑1H‑imidazol‑3‑ium) iodide ionic liquid (TAIm[I] IL) monomer with disodium salts of various open-chain carboxylic acids as well as sulfonic acids via a polycondensation on counter ions (PC-CI). Change in alkyl group length in carboxylate, as well as sulfonate, provide a broad spectrum of properties in terms of viscosity, density, and solubility for the resulting PILs. The physical properties of the PILs including, viscosity, melting point, boiling point, density,M¯n, and polydispersity (Ð), were determined in this study. Also, thermal behavior of the PILs were studied in comparison with the corresponding monomers. The ecofriendly PILs served as an efficient solvent and ligand for the Cu-catalyzed Heck and Sonogashira CC coupling reactions. High to excellent yields were obtained for various coupling products under mild conditions at melting points of the PILs. Also, the coupling products could be obtained with direct scalability. The prepared PILs could be recycled several times from the homogenous reaction mixture with preservation of the intrinsic properties. Also, a detailed study was conducted on the mechanism of the coupling reactions.

Chloride Ion‐Containing Polymeric Ionic Liquids for Application as Electrolytes in Solid‐State Batteries

AbstractOrganic, solid‐state batteries require efficient solid electrolytes able to provide stable ion conduction. Here, solid electrolytes based on ionic liquid (IL) polymers with chloride counterions as electrolyte materials for batteries are presented. Acrylic monomers with imidazolium substituents with alkyl side groups that are linked by alkyl spacers to the acrylic group are employed. The IL monomers with chloride counterions are either converted by thermally initiated radical polymerization into linear homopolymers or incorporated into polymer networks by UV‐initiated copolymerization utilizing a bifunctional, non‐ionic cross‐linker. Both procedures successfully yielded the desired materials, which is confirmed by NMR spectroscopy (linear homopolymers) or Raman spectroscopy (IL networks). The ionic conductivities at room temperature are measured by Electrochemical Impedance Spectroscopy. The ionic conductivities of the linear homopolymers are in the range of 10−4 to 10−6 S cm−1, while those of the IL networks are about two orders of magnitude lower. They increase to 10−4 S cm−1 at 70 °C. The electrochemical stability is examined by Linear Sweep Voltammetry and is proven in the voltage range of −2 to +2 V. The results reveal that the materials represent promising electrolytes for potential solid‐state battery applications.

Synthesis and Physicochemical Properties of Acrylate Anion Based Ionic Liquids.

Two polymerizable ionic liquids (or monomeric ionic liquids, mILs) namely 1-butyl-3-methylimidazolium and choline acrylates ([C4mim]A and ChA, respectively) were synthesized using the modified Fukumoto method from corresponding chlorides. The chemical structure of the prepared mILs was confirmed with FTIR and NMR study. Investigation of the thermal properties with DSC demonstrates that both mILs have a Tg temperature of about 180 K and a melting point around 310 K. It was shown that the temperature dependence of FTIR confirm the Tg to be below 200. Both mILs exhibited non-Newtonian shear thinning rheological behavior at shear rates >4 s−1. It was shown that [C4mim]A is able to dissolve bacterial cellulose (BC) leading to a decrease in its degree of polymerization and recrystallisation upon regeneration with water; although in the ChA, the crystalline structure and nanofibrous morphology of BC was preserved. It was demonstrated that the thixotropic and rheological properties of cellulose dispersion in ChA at room temperature makes this system a prospective ink for 3D printing with subsequent UV-curing. The 3D printed filaments based on ChA, containing 2 wt% of BC, and 1% of N,N′-methylenebisacrylamide after radical polymerization induced with 1% 2-hydroxy-2-methylpropiophenone, demonstrated Young’s modulus 7.1 ± 1.0 MPa with 1.2 ± 0.1 MPa and 40 ± 5% of strength and ultimate elongation, respectively.

Pharmaceutical Functionalization of Monomeric Ionic Liquid for the Preparation of Ionic Graft Polymer Conjugates

Polymerizable choline-based ionic liquid (IL), i.e., [2-(methacryloyloxy)ethyl]-trimethylammonium (TMAMA/Cl¯), was functionalized by an ion exchange reaction with pharmaceutical anions, i.e., cloxacillin (CLX¯) and fusidate (FUS¯), as the antibacterial agents. The modified biocompatible IL monomers (TMAMA/CLX¯, TMAMA/FUS¯) were copolymerized with methyl methacrylate (MMA) to prepare the graft copolymers (19-50 mol% of TMAMA units) serving as the drug (co)delivery systems. The in vitro drug release, which was driven by the exchange reaction of the pharmaceutical anions to phosphate ones in PBS medium, was observed for 44% of CLX¯ (2.7 μg/mL) and 53% of FUS¯ (3.6 μg/mL) in the single systems. Similar amounts of released drugs were detected for the dual system, i.e., 41% of CLX¯ (2.2 μg/mL) and 33% of FUS¯ (2.0 μg/mL). The investigated drug ionic polymer conjugates were examined for their cytotoxicity by MTT test, showing a low toxic effect against human bronchial epithelial cells (BEAS-2B) and normal human dermal fibroblasts (NHDF) as the normal cell lines. The satisfactory drug contents and the release profiles attained for the well-defined graft polymers with ionically bonded pharmaceuticals in the side chains make them promising drug carriers in both separate and combined drug delivery systems.

Rational Design of Solid Polymer Electrolyte Based on Ionic Liquid Monomer for Supercapacitor Applications via Molecular Dynamics Study.

The safety concern arising from flammable liquid electrolytes used in batteries and supercapacitors drives technological advances in solid polymer electrolytes (SPEs) in which flammable organic solvents are absent. However, there is always a trade-off between the ionic conductivity and mechanical properties of SPEs due to the lack of interaction between the ionic liquid and polymer resin. The inadequate understanding of SPEs also limits their future exploitation and applications. Herein, we provide a complete approach to develop a new SPE, consisting of a cation (monomer), anion and hardener from ions-monomers using molecular dynamics (MD) simulations. The results show that the strong solid-liquid interactions between the SPE and graphene electrode lead to a very small gap of ∼5.5 Å between the components of SPE and electrode, resulting in a structured solid-to-liquid interface, which can potentially improve energy storage performance. The results also indicated the critical role of the mobility of free-standing anions in the SPE network to achieve high ionic conductivity for applications requiring fast charge/discharge. In addition, the formations of hardener-depleted regions and cation-anion-poor/rich regions near the uncharged/charged electrode surfaces were observed at the molecular level, providing insights for rationally designing the SPEs to overcome the boundaries for further breakthroughs in energy storage technology.

From the Design of Novel Tri- and Tetra-Epoxidized Ionic Liquid Monomers to the End-of-Life of Multifunctional Degradable Epoxy Thermosets

From the Design of Novel Tri- and Tetra-Epoxidized Ionic Liquid Monomers to the End-of-Life of Multifunctional Degradable Epoxy Thermosets

Synthesis and photoinitiated polymerization of new ionic liquid methacrylates

AbstractSynthesis of new ionic liquid methacrylates and dimethacrylates is described comprising ammonium structures and various anions (bis(trifluoromethylsulfonyl)imide (NTf2), tris(pentafluoroethyl)trifluorophosphate (FAP), triflate (TFl), and trifluoroacetate (TFAc)). The structure of the anion has a stronger effect on both melting behavior and photopolymerization kinetics compared to the cation pattern. Photo‐differential scanning calorimetry investigation shows significant differences in the polymerization rate and final conversion depending on both the polymerization technique (bulk or solution polymerization using an ionic liquid as solvent) and the ionic liquid monomer under consideration. The results show that NTf2 or FAP should be preferred as anion over TFl and TFAc in the crosslinking photoinitiated polymerization because NTf2 and FAP result in both faster polymerization and higher final conversion. Interestingly, the presence of an ionic liquid methacrylate comprising the same anion as the ionic liquid dimethacrylate during the photoinitiated polymerization of the ionic liquid dimethacrylates results in an increase in final conversion that may be caused by lower crosslink density of the network formed, and therefore, higher mobility during the crosslinking process.

Immobilization of carbonic anhydrase in a hydrophobic poly(ionic liquid): A new functional solid for CO2 capture

Poly(ionic liquid)s are interesting materials for CO2 separation due to their affinity towards CO2. Carbonic anhydrase, as an enzyme that catalyzes the hydration reaction of CO2, represents tremendous opportunities for enhanced CO2 capture in aqueous solutions. Yet, when used as a free enzyme solubilized in the liquid medium, it has limited practicality. Here, we report the study on carbonic anhydrase immobilization in poly(ionic liquid)s by entrapment. Due to limited enzyme solubility in the hydrophobic ionic liquid monomer solution, carbonic anhydrase was suspended instead of solubilized prior to bulk polymerization. The immobilization protocol was optimized to maximize the catalytic efficiency of the resulting solid by evaluating the effect of lyophilized suspension hydration and particle size. Immobilized carbonic anhydrase properties were investigated by measurement of kinetic parameters, reusability, thermal and storage stability. Using p-NPA hydrolysis as a model reaction, kinetic parameters were 0.22 s−1 mM−1 (kcat/Km) for free enzyme and 0.06 s−1 mM−1 for the immobilized biocatalyst, indicating a decrease of activity upon immobilization. Immobilized enzyme, however, presented better storage stability than free enzyme as after one month the activity did not change. In the case of dissolved carbonic anhydrase, it decreased by about 30%. The entrapped enzyme could be utilized in 5 consecutive cycles of CO2 hydration while keeping a relative activity superior to 60%.

Ion-/Thermo-Responsive fluorescent perylene-poly(ionic liquid) conjugates: One-pot microwave synthesis, self-aggregation and biological applications

This manuscript describes the attachment of alkylvinylimidazolium-based poly(ionic liquid) (PIL) to the imide positions of perylene bisimide (PBI) to introduce stimuli-responsiveness and to make the conjugate soluble in water and water-based mixed solvents with the possibilities of using them as a probe for imaging and diagnostics in biomedical domain. The alkylvinylimidazolium ionic liquid monomers (ILMs) are tailor-made and a one-step microwave-assisted method is employed for synthesizing the PBI-(Cys-PIL)2 conjugates by thiol-mediated radical polymerization of the ILMs using l-cysteine (Cys) with AIBN as initiator and in the presence of perylene-3,4,9,10-tetracarboxylic dianhydride (PDA). The introduction of PIL segment induces amphiphilicityto the conjugate, and it undergoes self-aggregation into vesicles in water and methanol/water mixture. Owing to the presence of PIL segments, the conjugates are responsive to anions forming insoluble spherical aggregates through the multipoint ionic crosslinking between the cationic PIL segments of neighbouring conjugate molecules in water and methanol/water mixture. The turbid color dispersion, containing spherical conjugate’s aggregates, shows upper critical solution temperature (UCST)-type phase transition to transparent solution upon heating. The variation of cloud point of conjugate could be done by changing different parameters such as molecular weight, nature of anions, and the length of the alkyl chain present in the PIL segment of the conjugate. The UV–vis and fluorescence spectra of the conjugate’s aggregates in solution change upon addition of anions. The monitoring of the spectral change upon heating due to disruption of aggregates allows us to determine the cloud point, which exactly matches with that obtain from turbidimetry. The water-soluble fluorescent PBI-(Cys-PIL)2 conjugate having cationic PIL segments shows low cytotoxicity and can be used in binding with ctDNA/plasmid DNA and imaging HeLa cells.

ZIF-8/styrene-IL polymerization hollow fiber membrane for improved CO2/N2 separation

Compared to supported ionic liquid membranes, poly(ionic liquid) membranes are synthesized by the polymerization of ionic liquid monomers to develop polymeric backbone to improve its membrane stability for gas separation process. However, the resulting dense membrane structure induced the lower gas permeance of the poly(ionic liquid) membranes. To overcome this limitation, in this study, ZIF-8, possessing the property of molecular sieves, was added to poly(styrene-ionic liquid) hollow fiber membranes (p(SIL) HFMs), providing a transport pathway. SIL monomers with different lengths of alkyl chain were polymerized and integrated with ZIF-8 fillers to synthesize ZIF-8/poly(ionic liquid) mixed matrix hollow fiber membranes (ZIF-8/p(SIL) MMHFMs). When the chain length of SIL monomers was increased, the CO2 permeance of p(SIL) HFMs increased from 3.6 to 4.6 GPU, while CO2/N2 selectivity decreased from 29 to 23. Additionally, the CO2 permeance of ZIF-8/p(SIL) MMHFMs was enhanced by 33% compared to that of p(SIL) HFMs. However, chain rigidification phenomenon was observed which cause the ZIF-8/p(SIL) MMHFMs showed the decreasing CO2 permeance when the ZIF-8 content was increased. The best separation performance of ZIF-8/p(SIL) MMHFMs was obtained with 0.5 wt% ZIF-8 addition, which exhibited a CO2 permeance and CO2/N2 selectivity of 6 GPU and 30. Therefore, adding ZIF-8 into p(SIL) HFMs to form the ZIF-8/p(SIL) MMHFMs is beneficial to enhance the CO2 permeance of membranes because of the characteristic of the pore size of 3.4 Å and transport pathway provided by ZIF-8 fillers.

Colorimetric and electrochemical detection platforms for tetracycline based on surface molecularly imprinted polyionic liquid on Mn3O4 nanozyme

In this work, a smart tetracycline (TC) imprinted material (DSMIP@Mn3O4) is prepared via atom transfer radical polymerization of dual ionic liquid (IL) monomers on the surface of Mn3O4 nanoparticles. The obtained DSMIP@Mn3O4 shows a core-shell structure with a sphere shape and has high oxidase-like activity and recognition ability. It has been used to construct colorimetric and electrochemical detection platforms for TC. The colorimetric detection is based on the recombined TC blocking the molecular channels on the surface of DSMIP@Mn3O4, which hinders the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine to the blue product. The linear detection range is 0.5 μM–150 μM and the low detection limit is 0.1 μM. This system is further developed for the visual semi-quantitative detection of TC by using a smartphone. Furthermore, the DSMIP@Mn3O4 is combined with IL-modified carbon nanotube-graphene composite for the sensitively electrochemical detection of TC, which shows a wide linear range of 0.01 μM–20 μM and a low detection limit of 5 nM. The proposed methods have high selectivity and reproducibility and suit different detection situations. Their pracibility is evaluated by determining TC in different samples, and the measurement results are consistent with that obtained by high-performance liquid chromatography. Hence, the colorimetric and electrochemical detection platforms have good application potential.

Polymeric ionic liquid membranes for the absorption-conversion of CO2 and epoxides into cyclic carbonates

Polymeric ionic liquid membranes (PILMs) were prepared by photo-initiated polymerization of DMAEMA-based ionic liquids (ILs) and co-monomers for the conversion of CO2 into cyclic carbonates. The influences of functional groups and anions were investigated to find the optimal ionic liquid monomer. The PILM based on [DMAEMA-EtOH]Br exhibited the highest propyl carbonate (PC) yield (98%), which was close to that of the [DMAEMA-EtOH]Br monomer. Moreover, the PILMs can catalyze the gas state propylene oxide (PO) and CO2 into PC with a PO conversion of 87.3%, while the PO conversion of the pure polymeric ionic liquids was only 3.1% for gas state PO. The excellent catalytic activity can be attributed to the highly active catalytic sites and superb swelling ability of PILMs. The dry PILMs could absorb the PO vapor and swell into membranes with abundant pores, which contained plentiful active sites to catalyze PO and CO2 to PC efficiently.

On the quest for novel bio-degradable plastics for agricultural field mulching.

Plasticulture, the practice of using plastic materials in agricultural applications, consumes about 6.7 million tons of plastics every year, which is about 2% of the overall global annual plastics production. For different reasons, plastic material used for agriculture is difficult to recycle. Therefore, most of it is either buried in fertile soils, thereby significantly causing deterioration of their properties, or, at best case, end in landfills where its half-life is measured in decades and even centuries. Hence, developing biodegradable plastic materials that are suitable for agricultural applications is a vital and inevitable need for the global human society. In our labs, two types of potentially biodegradable plastic polymer films were prepared and characterized imidazolium in terms of their bio-degradability. In the first approach, polymers made of ionic liquid monomers were prepared using photo radical induced polymerization. The second approach relies on formation of polyethylene-like n-alkane disulfide polymers from 1,ω-di-thiols through thermally activated air oxidation. These two families of materials were tested for their biodegradability in soils by using a simulation system that combines a controlled environment chamber equipped with a respirometer and a proton-transfer-reaction time of flight mass spectrometer (PTR-TOF-MS) system. This system provides a time-dependent and comprehensive fingerprint of volatiles emitted in the degradation process. The results obtained thus far indicate that whereas the ionic-liquid based polymer does not show significant bio-degradability under the test conditions, the building block monomer, 1,10-n-decane dithiol, as well as its disulfide-based polymer, are bio-degradable. The latter reaching, under basic soil conditions and in room temperature, ∼20% degradation within three months. These results suggest that by introduction of disulfide groups into the polyethylene backbone one may be able to render it biodegradable, thus considerably shortening its half-life in soils. Principal component analysis, PCA, of the data about the total volatiles produced during the degradation in soil indicates a distinctive volatile “fingerprint” of the disulfide-based bio-degradable products which comes from the volatile organic compounds portfolio as recorded by the PTR-TOF-MS. The biodegradation volatile fingerprint of this kind of film was different from the “fingerprint” of the soil background which served as a control. These results can help us to better understand and design biodegradable films for agricultural mulching practices.

Construction of hyper-crosslinked ionic polymers with high surface areas for effective CO2 capture and conversion

The design and preparation of ionic liquids functionalized polymer materials is a trending topic in the fields of polymer science for CO2 capture and utilization. In this work, a series of porous hyper-crosslinked ionic polymers (PIPs) with high surface area and abundant catalytic central units have been synthesized by a simple post-crosslinking of ionic liquid monomer and 4,4′-bis(chloromethyl)-1,1′-biphenyl. The prepared PIPs were used for CO2 adsorption, and their adsorption capacity for CO2 exceeded 100 mg g−1 at 273 K and 1.0 bar. Furthermore, the isotherm adsorption data of CO2 were fitted respectively by Langmuir, Freundlich, Redlich-Peterson, and Toth isotherm models to calculate the thermodynamic parameters, including changes in Gibbs free energy (ΔG°), enthalpy (ΔH°), entropy (ΔS°), and isosteric heat of adsorption (ΔHIsosteric). It is concluded that the adsorption process of CO2 on PIP is a spontaneous physical process. These PIP can also be used as heterogeneous catalysts for the cycloaddition of CO2 with epoxides under metal/solvent/cocatalyst-free conditions. The excellent yields (up to 99%) of cyclic carbonates are ascribable to synergistic contributions of abundant microporous and active ionic catalytic centers. This study provides a new idea for developing functionalized ionic polymers that combine capture and conversion of CO2.

Synthesis of Functionalized 1-cyclooctyl-3-methyl-1,2,3-triazolium via click chemistry and their polymerization by ROMP

This paper describes the synthesis of a new ionic liquid (IL) monomer of 5-substituted cyclooctene 1,2,3-triazolium iodides salt via click chemistry, and an anion exchange reaction with two different counteranions: bis(trifluoromethylsulfonyl)imide [N(SO2CF3)2]−(NTf2−), and hexafluorophosphate ([PF6]−). The structural properties of all monomers were determined by MALDI-TOF-MS, (1H; 13C; 19F;)NMR spectroscopy. 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) with the pendant triazolium moieties were also synthesized by Ring-Opening Metathesis Polymerization (ROMP) using Grubbs second generation (Grubbs II) ruthenium as a catalyst with good control during the polymerization process and gave viscous solutions. The Synthesis of the polymers (TPILs) was confirmed by 1HNMR spectroscopy. The thermal properties were characterized by thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The thermal stability of monomers was found to be high (∼286°C). Furthermore, monomers salts with [NTf2−] have low melting points below 100°C (25-99°C), and their TPILs are viscous liquids at room temperature, with a low glass transition temperature (Tg = -23°C). This result suggests that the 5-substituted cyclooctene 1,2,3-triazolium ionic liquid monomer offers high chain flexibility to the resulting polymers (TPILs). Hence this new class of IL monomer and TPILs may be potentially useful in electrolyte membrane applications.

Guanidine-embedded poly(ionic liquid) as a versatile precursor for self-templated synthesis of nitrogen-doped carbons: Tailoring the microstructure for enhanced CO2 capture

A series of N-doped carbons coupled with ultra-micropores were synthesized through a self-templated strategy by employing the guanidine-embedded poly(ionic liquid) as the versatile precursor. The crosslinking agent (N,N’-methylene bisacrylamide (MBA)) and the ionic liquid monomer (1-(4-vinylbenzyl)-tetramethylguanidinium chloride) distributed in the polymeric frameworks exerted the functions of not only the pore-forming agents, but also the nitrogen sources during pyrolysis. With the cooperation of these two components, the derived carbon materials were endowed with well-developed microporosity and evenly-dispersed nitrogen species. Besides, the divinylbenzene (DVB) was also an indispensable moiety to maintain the skeleton stability in the initial heating stage. Inspiringly, when the carbonization temperature and amount of KOH activator were selected as 700 °C and 2 mol/L, a large specific surface area of 1606.1 m2/g, a high ultra-micropore (<0.7 nm) content of 0.4314 cm3/g along with abundant pyrrolic-N sites were attained, contributing to the appealing performance for CO2 capture. The adsorption capacity of the CTMG-700 achieved 3.95 mmol/g, and the selectivity toward CO2/N2 mixture (VCO2/VN2 = 15/85) was 20.4 at 25 °C and 1 bar. This strong affinity for CO2 molecules was credited to the superposition of van der Waals’ force inside narrow ultra-micropores as well as the hydrogen-bonding and acid-base interactions originated from pyrrolic-N. In addition, the CTMG-700 also demonstrated satisfactory cyclic adsorption performance under mild regeneration conditions. The present work was intended to uncover a new strategy to construct advanced carbonaceous materials via tailoring the microstructure of poly(ionic liquid)-based precursors for gas separation or specific applications.

Nanofiltration Membranes Modified with a Clustered Multiquaternary Ammonium-Based Ionic Liquid for Improved Magnesium/Lithium Separation.

Lithium separation is of great significance to overcome the lithium supply shortage resulting from a heightened demand in the energy sector. The low selectivity of polymer nanofiltration membranes for lithium extraction from concentrated Mg/Li mixtures caused by miniaturized pore structures and weak and unstable positive surface charges limits their practical implementation. To address the surface charge strength and stability, a novel ionic liquid monomer, N1-(6-aminohexyl)-N1,N1,N6,N6,N6-pentamethylhexane-1,6-diaminium bromide (denoted as DABIL), is first synthesized and covalently anchored on a pristine polyamide thin-film composite (TFC) membrane via a secondary amidation reaction for improved selective lithium separation from Mg/Li mixtures. DABIL modification of the polyamide network contributes to increased surface hydrophilicity, an enlarged membrane pore structure, and reinforced Donnan exclusion effects. Molecular dynamics simulation confirmed that the difference of the interaction energies between water and the multication groups dominates the surface properties. The DABIL membrane exhibits sixfold enhancement of water permeability compared to the unmodified membrane and outperforms the recently reported state-of-the-art positively charged membranes. It presents an improved Li+/Mg2+ selectivity of 26.49, suggesting the membranes' potential for lithium recovery. Moreover, the membrane shows efficient antibacterial activity for mitigating biofilm formation. We establish that functionalization of TFC membranes with ionic liquids containing multication side chains could be a promising approach to achieve improved and sustainable permselectivity for the recovery of critical metal resources.

Linear polyurethane ionenes for stable interlayer of organic photovoltaics

Non-conjugated polymer electrolytes (nCPEs) are applied as electron transporting layers (ETLs) in organic photovoltaic (OPV) devices with conventional structures and used as competent interfacial layers. The new nCPEs are prepared from dihydroxyl pyrrolidinium bromide ionic liquid monomers and m-diphenylene diisocyanate to create linear polyurethane ionenes with main-chain ionic salt moieties. The ultraviolet photoelectron spectroscopy (UPS) results reveal that the formation of an interfacial dipole by the nCPEs facilitates electron transfer from the photoactive layer to the electrode. The OPV devices with the new nCPEs show a power conversion efficiency (PCE) comparable to that with the well-known conjugated polymer electrolyte poly(9,9-bis(3’-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene))dibromide (PFN), which possesses charged sites on its pendants, as an ETL. The OPV device with the synthesised nCPE exhibits superior stability compared to the PFN-based OPV devices. Our results suggest that the nCPEs containing ionic salt structures on polymer main chains are more suitable ETLs for OPV devices than PFN-based layers with pendant salt moieties.

Sulfonates as Versatile Structural Counterions of Epoxidized Salts.

Ionic liquids have recently emerged as monomers to synthesize multifunctional polymeric materials. Among such species, ionic epoxy-based networks represent promising but underdeveloped materials that are hindered by tricky access to the functionalized ionic liquid monomers. To date, the reported epoxidized imidazolium salts have focused on highly toxic epichlorohydrin. This study concerns flexible and efficient methods to synthesize versatile building blocks with sulfonates as valuable anions. The judicious combination of an aliphatic or aromatic sulfonate with an imidazolium leads to new epoxidized salts with high structural variability and good chemical and thermal stability (>300 °C).