Ionic Liquid Cations Research Articles

Effects of Ionic Liquid Content on the Electrical Properties of PVDF Films by Fused Deposition Modeling.

In this study, polyvinylidene fluoride (PVDF) composite films were prepared by fused deposition modeling, and the effects of ionic liquid (IL) content on the printability, crystallization behavior, and electrical properties of melted PVDF were systematically investigated. The results show that the addition of IL increased the temperature sensitivity of melted PVDF and decreased its viscosity, while IL acted as a plasticizer to lower the melting point of PVDF and improve its FDM printability. The imidazole cations in IL had electrostatic interactions with the -CF2- groups in PVDF, which promoted the transformation of the nonpolar phase to the polar phase in PVDF; thus, the addition of IL was beneficial to the increase in the polar β phase. The PVDF with 20 wt.% IL contained the highest proportion of β phase content (32.59%). Moreover, the increase in polar β-phase content also increased the polarization strength of PVDF and improved its ferroelectric properties. PVDF with 10 wt.% IL had the highest residual polarization strength (16.87 μC/m2).

Hydrogen-bonding and π-π interaction promoted solution-processable covalent organic frameworks

Covalent organic frameworks show great potential in gas adsorption/separation, biomedicine, device, sensing, and printing arenas. However, covalent organic frameworks are generally not dispersible in common solvents resulting in the poor processability, which severely obstruct their application in practice. In this study, we develop a convenient top-down process for fabricating solution-processable covalent organic frameworks by introducing intermolecular hydrogen bonding and π-π interactions from ionic liquids. The bulk powders of imine-linked, azine-linked, and β-ketoenamine linked covalent organic frameworks can be dispersed homogeneously in optimal ionic liquid 1-methyl-3-octylimidazolium bromide after heat treatment. The resulting high-concentration colloids are utilized to create the covalent organic framework inks that can be directly printed onto the surface. Molecular dynamics simulations and the quantum mechanical calculations suggest that C‒H···π and π-π interaction between ionic liquid cations and covalent organic frameworks may promote the formation of colloidal solution. These findings offer a roadmap for preparing solution-processable covalent organic frameworks, enabling their practical applications.

Fabrication of biodegradable cellulose acetate nanofibers containing Rose Bengal dye by electrospinning technique and their antiviral efficacy under visible light irradiation

Biodegradable cellulose acetate (CA) nanofibers containing Rose Bengal (RB) dye were fabricated by electrospinning technique. RB dye, an anionic photosensitizer, has been used in photodynamic therapy due to its excellent biocompatibility and ability to absorb light to generate reactive oxygen species (ROS), but has a decisive disadvantage of water solubility on infection prevention. Firstly, water-insoluble RB dye was synthesized through complexation with cationic ionic liquid (IL) for antiviral agents. The synthesized water-insoluble RB dyes were embedded into biodegradable CA nanofibers by electrospinning. The electrospun nanofibers passed both antiviral test for φx174 virus under visible light irradiation and biodegradability-test using enzymes. The fabricated RB nanofibers absorbed light and generated ROS to inactivate the virus. As a result, the log reduction (-Log10(N/N0)) of φx174 titer under visible light reached a detection limit of 5.00 within 30 min. Also, the fabricated nanofibers were degraded up to 34 wt % in 9 weeks by lipase and cellulase enzymes compared with non-biodegradable nanofibers.

DFT-based investigation of solvation of Nd(III)/Yb(III) cations in room-temperature ionic-liquid

We report a DFT study on the solvation of bare rare-earth (RE) cations [Nd(III) and Yb(III)] in the room-temperature ionic-liquid (RTIL) based on 1,3-dimethyl-imidazolium+, PF6−, [MMI][PF6]. In the present article, we aim to investigate whether the chosen RTIL can preferentially solvate any of the RE cations under study. First, the RTIL binding to the RE cation is studied in the gas phase, and then explored with continuum solvation model employing RTIL parameters. First, we considered the formation of the first solvation shell, where the PF6− anions directly bond with the Ln(III) cation. We then further surrounded the first solvation shell with [MMI]+ cations to form the second solvation shell. The stability of PF6− coordinated complexes is studied by calculating the binding energy values. The number of PF6− anions for both Ln(III) cations starts with three ligands and goes until the maximum binding energy in the RTIL medium is reached. The coordination number and binding modes of PF6− depend on the size of the RE cation. Comparing the binding energy values between the RE cations for the first solvation shell complexes, it is noticed that Yb-complexes have relatively greater binding energy than Nd-complexes. We have further performed a Boltzmann population analysis to find out the most dominant conformer among each category of PF6− coordinated complexes. A study using Natural Population Analysis shows that after complexation with PF6− the charge on the Yb-centers lower to a greater extent than Nd-centers, implying stronger bonding between Yb and PF6−, which is in harmony with the binding energy analysis. Overall, the computational investigation provides an in-depth understanding of the complexation phenomena of RE cations in RTIL, which can be useful for the practical separation of RE cations using RTIL.

Fractionation of Arctic Brown Algae (Fucus vesiculosus) Biomass Using 1-Butyl-3-methylimidazolium-Based Ionic Liquids.

Arctic brown algae are considered a promising industrial-scale source of bioactive sub-stances as polysaccharides, polyphenols, and low-molecular secondary metabolites. Conventional technologies for their processing are focused mainly on the isolation of polysaccharides and involve the use of hazardous solvents. In the present study a "green" approach to the fractionation of brown algae biomass based on the dissolution in ionic liquids (ILs) with 1-butil-3-methylimidazolium (bmim) cation with further sequential precipitation of polysaccharides and polyphenols with acetone and water, respectively, is proposed. The effects of IL cation nature, temperature, and treatment duration on the dissolution of bladderwrack (Fucus vesiculosus), yields of the fractions, and their chemical composition were studied involving FTIR and NMR spectroscopy, as well as size-exclusion chromatography and monosaccharide analysis. It was shown that the use of bmim acetate ensures almost complete dissolution of plant material after 24 h treatment at 150 °C and separate isolation of the polysaccharide mixture (alginates, cellulose, and fucoidan) and polyphenols (phlorotannins) with the yields of ~40 and ~10%, respectively. The near-quantitative extraction of polyphenolic fraction with the weight-average molecular mass of 10-20 kDa can be achieved even under mild conditions (80-100 °C). Efficient isolation of polysaccharides requires harsh conditions. Higher temperatures contribute to an increase in fucoidan content in the polysaccharide fraction.

Synthesis, characterization, and studies of the interfacial and anticorrosion properties of a ternary cationic ionic liquid on carbon steel in a molar concentration of hydrochloric acid: Experimental and computational insights

Corrosion in acidic environments is a serious industrial challenge that must be addressed and cationic ionic liquid play a critical role in tackling the wet corrosion menace for the metal industry. For this purpose, a novel ternary cationic ionic liquid namely N1-(3-(11-(octadecyldimethylammonio)undecanamido)propyl)-N1,N1,N2,N2,N2-pentamethylethane-1,2-diaminium tribromide (Mono-18–11-di-N) is synthesized and elucidated for anticorrosion activity on St37–2 grade steel in a molar concentration of hydrochloric acid medium. The structural elucidation of Mono-18–11-di-N was achieved by FT-IR, 1H NMR, and 13C NMR methods while the electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), dynamic-EIS, density functional theory (DFT) calculations, and Monte Carlo (MC) simulation techniques were adopted in the anticorrosion evaluation. The Critical Micelle Concentration (CMC) of Mono-18–11-di-N is 0.000491 M and at CMC, the surface tension is 21.86 dyn cm−1 inferring good surface activity properties. Mono-18–11-di-N is effective against the wet corrosion of St37–2 steel. It can, at 20 mg/L decrease the corrosion rate of the metal from 0.57 mm/y to 0.11 mm/y and enhance the polarization resistance from 363 Ω cm2 to 1908 Ω cm2. A corrosion rate of 0.03 mm/y and an inhibition efficiency of 93% is achievable after 24 h of immersion at 25 °C. Additionally, surface morphological examination using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), optical profilometer (OP), and atomic force microscope (AFM) methods prove the adsorption of Mono-18–11-di-N molecules on the substrate surface. Moreover, DFT and MC simulations revealed that Mono-18–11-di-N relies on lone pairs of electrons in bromide anion, oxygen, and nitrogen atoms to adsorb parallel to the St37–2 surface and protect it against corrosion.

Impact of ionic liquid's cation alkyl chain length and reaction time on cellulose nanocrystals preparation

Traditional methods to obtain cellulose nanocrystals typically involve mechanical and chemical processes and develop an improved process in terms of efficiency, sustainability, and the quality of CNCs produced are interesting. In this sense, we aimed to prepare cellulose nanocrystals (CNCs) from the hydrolysis of microcrystalline cellulose using protic ionic liquids (PILs), named 3-diethylamino-propylammonium hexanoate ([DEAPA][Hex]), 3-dimethylamino- 1-propylammonium hexanoate ([DMAPA][Hex]), and propylammonium hexanoate ([PA][Hex]) at different reaction times. The PILs demonstrated efficiency in producing cellulose nanocrystals, regardless of the cation size and reaction times. However, as expected the properties of the CNCs varied depending on the studied condition. The highest yield was observed in DMAPA[Hex], with a 34 % conversion. Crystalline indices decreased independent of the cation sizes and reaction times. Thermal stabilities were shifted to higher temperatures up to 92 ºC probably due to PILs cation sizes. In contrast, increasing reaction times decreased nanocrystals’ thermal stabilities up to 51ºC. So, protic ionic liquids (PILs) can be considered more environmentally friendly or sustainable solvents compared to traditional organic solvents for preparing cellulose nanocrystals. In the present work, it is reported an alternative method for obtaining CNCs and additionally provide the best preparation conditions for achieving important properties of this nanomaterial, with the potential for various applications.

Lysozyme aggregation and unfolding in ionic liquid solvents: Insights from small angle X-ray scattering and high throughput screening

Understanding protein behaviour is crucial for developing functional solvent systems. Ionic liquids (ILs) are designer salts with versatile ion combinations, where some suppress unfavourable protein behaviour. This work utilizes small angle X-ray scattering (SAXS) to investigate the size and shape changes of model protein hen egg white lysozyme (HEWL) in 137 IL and salt solutions. Guinier, Kratky, and pair distance distribution analysis were used to evaluate the protein size, shape, and aggregation changes in these solvents. At low IL and salt concentration (1 mol%), HEWL remained monodispersed and globular. Most ILs increased HEWL size compared to buffer, while the nitrate and mesylate anions induced the most significant size increases. IL cation branching, hydroxyl groups, and longer alkyl chains counteracted this size increase. Common salts exhibited specific ion effects, while the IL effect varied with concentration due to complex ion-pairing. Protein aggregation and unfolding occurred at 10 mol% IL, altering the protein shape, especially for ILs with multiple alkyl chains on the cation, or with a mesylate/nitrate anion. This study highlights the usefulness of adopting a high-throughput SAXS strategy for understanding IL effects on protein behaviour and provides insights on controlling protein aggregation and unfolding with ILs.

Short alkyl-imidazolium ionic liquids enhanced in-situ transesterification of microalgae

Ionic liquids (ILs) catalyzed in-situ transesterification (IST) of microalgae is a promising strategy to improve biodiesel yield through enhancing cellulose solubility and catalyzing transesterification. Effect of anions of ILs on biodiesel has been widely investigated previously. However, how do cations of ILs affect IST of microalgae is still unclear. On this basis, ILs composed of alkyl-imidazolium cations with different length, 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), and 1-hexyl-3-methylimidazolium tetrafluoroborate ([Hmim][BF4]) catalyzed IST of microalgae are experimentally and theoretically investigated. The results indicate that increasing alkyl chains of cations weakens interactions of ILs-cellulose, and reduces acidities of ILs, subsequently leads to decrease of cellulose extraction yield and biodiesel yield. Although cellulose extraction yield and biodiesel yield are affected by reaction temperature, dosage of methanol, and MILs: Algae, however, H-bonding interactions of ILs-cellulose and acidities of ILs are still dominate parameters affecting cellulose extraction yield and biodiesel yield, respectively, leading to their unchanged sort under variable reaction conditions as following: [Emim][BF4] > [Bmim][BF4] > [Hmim][BF4]. This work reveals that short alkyl chain of cation is favorable to both cellulose extraction and biodiesel yield, providing theoretical guides for screen and design of benign ILs to further improve biodiesel of in-situ transesterification of microalgae.

Sorption of ionic liquids in soil enriched with polystyrene microplastic reveals independent behavior of cations and anions

Recently, much attention has been focused on the application of the Ionic Liquids (ILs) with herbicidal activity in agriculture. It has been suggested that through the appropriate selection of cations and anions, one can adjust the properties of ILs, particularly the hydrophobicity, solubility, bioavailability, toxicity. In practical agricultural conditions, it will be beneficial to reduce the mobility of herbicidal anions, such as the commonly applied 2,4-dichlorophenoxyacetic acid [2,4-D] in the soil. Furthermore, microplastics are becoming increasingly prevalent in the soil, potentially stimulating herbicidal sorption. Therefore, we investigated whether cations in ILs influence the mobility of anions in OECD soil supplemented with polystyrene microplastic (PS). For this purpose, we used the 2,4-D based ILs consisting of: a hydrophilic choline cation [Chol][2,4-D] and a hydrophobic choline cation with a C12chain [C12Chol][2,4-D]. Characterization of selected micropolystyrene was carried out using the BET sorption-desorption isotherm, particle size distribution and changes in soil sorption parameters such as soil sorption capacity and cation exchange capacity. Based on the batch sorption experiment, the effect of microplastic on the sorption of individual cations and anions in soil contaminated with micropolystyrene was evaluated. The results obtained indicate that the introduction of a 1–10% (w/w) PS resulted in an 18–23% increase of the soil sorption capacity. However, the sorption of both ILs’ cations increased only by 3–5%. No sorption of the [2,4-D] anion was noted. This suggests that cations and anions forming ILs, behave independently of each other in the environment.The results indicate the fact that ILs upon introduction into the environment are not a new type of emerging contaminant, but rather a typical mixture of ions. It is worth noting that when analyzing the behavior of ILs in the environment, it is necessary to follow the fate of both cations and anions.

Tuneable interphase transitions in ionic liquid/carrier systems via voltage control

The structure and interaction of ionic liquids (ILs) influence their interfacial composition, and their arrangement (i.e., electric double-layer (EDL) structure), can be controlled by an electric field. Here, we employed a quartz crystal microbalance (QCM) to study the electrical response of two non-halogenated phosphonium orthoborate ILs, dissolved in a polar solvent at the interface. The response is influenced by the applied voltage, the structure of the ions, and the solvent polarizability. One IL showed anomalous electro-responsivity, suggesting a self-assembly bilayer structure of the IL cation at the gold interface, which transitions to a typical EDL structure at higher positive potential. Neutron reflectivity (NR) confirmed this interfacial structuring and compositional changes at the electrified gold surface. A cation-dominated self-assembly structure is observed for negative and neutral voltages, which abruptly transitions to an anion-rich interfacial layer at positive voltages. An interphase transition explains the electro-responsive behaviour of self-assembling IL/carrier systems, pertinent for ILs in advanced tribological and electrochemical contexts.

Zwitterionic metal–organic framework with highly dispersed ionic liquid for enhancing CO2 capture

Ionic liquids (ILs) have been often incorporated into metal–organic framework (MOF) to improve the performance of gas adsorption and separation. However, ILs are prone to agglomerate in the pores of MOFs, which causes insufficient exposure of their active sites, thus significantly reducing the separation efficiency. Herein, we report a zwitterionic MOF UiO-66-SO3−-NH3+ with both positive and negative charges for enhanced ILs dispersion and CO2 capture. When the ILs were introduced into UiO-66-SO3−-NH3+, they can be highly dispersed in the pores of MOF through the electronic interaction between positive and negative charges of MOF and anion and cation of ILs, and the active sites of IL can be adequately exposed. Notably, this is the first report of IL@zwitterionic MOF composites for CO2 capture. Compared with the single group modified counterparts, namely IL@UiO-66-NH2 and IL@UiO-66-SO3H, IL@UiO-66-SO3−-NH3+ exhibits higher CO2 affinity, which increases its CO2 adsorption capacity by 36–45%. Moreover, the CO2/N2 and CO2/CH4 adsorption selectivities of UiO-66-SO3−-NH3+ are 3.6–5.0 times and 2.1–2.5 times higher than that of single-group modified counterparts, respectively. This work not only provides a method to realize the high dispersion of ILs in MOF via constructing the zwitterionic MOF, but also reports an excellent adsorbent for CO2 capture.

Effects of Zwitterions on Structural Anomalies in Ionic Liquid Glasses Studied by EPR.

Ionic liquids (ILs) form a variety of nanostructures due to their amphiphilic nature. Recently, unusual structural phenomena have been found in glassy ILs near their glass transition temperatures; however, in all studied cases, IL cations and anions were in the form of separate moieties. In this work, we investigate for the first time such structural anomalies in zwitterionic IL glasses (ZILs), where the cation and anion are bound in a single molecule. Such binding reasonably restricts mutual diffusion of cations and anions, leading to modification of nano-ordering and character of structural anomalies in these glassy nanomaterials, as has been investigated using Electron Paramagnetic Resonance (EPR) spectroscopy. In particular, the occurrence of structural anomalies in ZIL glasses was revealed, and their characteristic temperatures were found to be higher compared to common ILs of a similar structure. Altogether, this work broadens the scope of structural anomalies in ionic liquid glasses and indicates new routes to tune their properties.

Investigation of aggregation behavior and surface properties of cationic surface-active ionic liquids and sodium carboxymethylcellulose mixed systems

Abstract The impact of different concentrations of sodium carboxymethyl cellulose (NaCMC) on the micellization process in cationic, ester-functionalized, ethyl-substituted imidazolium-based surface-active ionic liquids (SAILs) ([C n Eeim]Br where, n = 12, 14, 16) were investigated using specific conductivity and surface tension measurements at 298 K. The study focused on determining the critical micelle concentration (CMC) of the three pure SAILs and their mixtures with NaCMC to evaluate various thermodynamic and interfacial parameters. The results showed that the CMC values decreased significantly with increasing hydrophobicity of the SAILs, while the CMC increased with a gradual increase in the NaCMC mole fraction in the SAIL–NaCMC mixed systems. It was observed that the excess free energy of micellization ( ∆ G e x m ${{\increment}G}_{ex}^{m}$ ) and the minimum free energy of surface at equilibrium ( ∆ G min s ${{\increment}G}_{\mathrm{min}}^{s}$ ) exhibited an opposite behaviour, indicating that the formed mixed micelles were stable while the formed surface was unstable. The results of this study are useful for evaluating the properties of SAIL–NaCMC mixed systems to improve and better understand their applications in the food, medical and cosmetic industries.

A DFT insight into structure, NBO, NCI, QTAIM, vibrational, and NLO properties of cationic amino acid ionic liquid [Pro-H]+BF4−

A DFT insight into structure, NBO, NCI, QTAIM, vibrational, and NLO properties of cationic amino acid ionic liquid [Pro-H]+BF4−

Boost of Gas Adsorption Kinetics of Covalent Organic Frameworks via Ionic Liquid Solution Process.

Adsorption, storage, and conversion of gases (e.g., carbon dioxide, hydrogen, and iodine) are the three critical topics in the field of clean energy and environmental mediation. Exploring new methods to prepare high-performance materials to improve gas adsorption is one of the most concerning topics in recent years. In this work, an ionic liquid solution process (ILSP), which can greatly improve the adsorption kinetic performance of covalent organic framework (COF) materials for gaseous iodine, is explored. Anionic COF TpPaSO3 H is modified by amino-triazolium cation through the ILSP method, which successfully makes the iodine adsorption kinetic performance (K80% rate) of ionic liquid (IL) modified COF AC4 tirmTpPaSO3 quintuple compared with the original COF. A series of experimental characterization and theoretical calculation results show that the improvement of adsorption kinetics is benefited from the increased weak interaction between the COF and iodine, due to the local charge separation of the COF skeleton caused by the substitution of protons by the bulky cations of ILs. This ILSP strategy has competitive help for COF materials in the field of gas adsorption, separation, or conversion, and is expected to expand and improve the application of COF materials in energy and environmental science.

Probing the impact of alkyl chain length of imidazolium ionic liquids on the conformational stability of collagen type-I from skin of Lutjanus erythropterus

Multispectroscopic techniques and molecular docking study were carried out to inspect the role of concentrations and cationic chain length of ionic liquids (ILs), on the secondary structure of collagen type-I. To attain this objective, a series of imidazolium ILs having same anion (Cl−) and a set of cations with varying chain length were used in this study. The ILs studied utilized are 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-hexyl-3-methylimidazolium chloride ([Hmim][Cl]), and 1-decyl-3-methylimidazolium chloride ([Dmim][Cl]). The effect of these ILs on collagen type-I was analyzed by using UV-vis, circular dichroism (CD), steady state fluorescence, time resolve fluorescence (TRF), synchronous fluorescence, dynamic light scattering (DLS), fourier transform infrared spectroscopy (FT-IR) and molecular docking approach. The results obtained shows the stability of the collagen was dependent on the alkyl chain length of cation as well as concentration of these ILs. The alteration in hydrogen bonding and hydrophobic interactions due to the different cations of ILs, with the amino acid residues, play a key role in unfolding/destabilization of collagen. Consequently, the destabilization propensity of the ILs toward the collagen increases with increasing chain length of ILs. In addition, when organized in the order of providing destability to collagen triple helix structure, the cations of the ILs obeyed the Hofmeister series. Molecular docking also confirms more hydrophobic interaction and reduced hydrogen bonding due to long alkyl chain length of cations in ILs. The docking results are in agreement with the spectroscopic results and provide the information about the ligand binding site on the protein.

Role of alkyl chain present in the cations of ionic liquids on stabilization of silver nanoparticle: DFT and TD-DFT studies

Understanding the preparation and stabilization of silver nanoparticles in ionic liquids is still needed to investigate. Various groups have reported the synthesis and stabilization of silver nanoparticles (Ag NPs) in ionic liquids (ILs) on varying the cation and anion. There is a need to understand the impact of alkyl chain present in the cation to understand the new interactions between the ILs with Ag NPs. Herein, the authors have designed the imidazolium ring based ionic liquids having tetrafluoroborate (TFB) as anion and the alkyl chain present on the cation is varied. The interactions have been studied through the DFT and TD-DFT calculations performed by Gaussian. Herein, free energy and other thermodynamic parameters of ILs with and without Ag are calculated. It came to know that the change in free energy for 3-Ag is least among all designed. 1-Ag is least stable as the change in free energy is positive at 298 K. On varying the alkyl chain, different types of interactions are observed. The same can be seen by localization of nucleophilic and electrophilic sites in the HOMO and LUMO of the ILs with and without Ag. Further, their dipole moments are also determined to understand the polarity of ILs with and without Ag and herein, no regular pattern is observed.

Synergistic Effect of Silver-Based Ionic Liquid for Ethylene/Ethane Separation

Separation of ethylene (C2H4) and ethane (C2H6) is one of the most significant processes in the petrochemical industry. In terms of industrial application, silver nitrate aqueous solution is the most widely used absorbent, but the activity of Ag+ and the absorption of C2H4 are not optimistic. Thus, it is urgent to explore new technologies for efficient separation of C2H4 and C2H6. In this work, several silver-based ionic liquid (Ag-IL) solutions are prepared with ionic liquids (ILs), silver salts, and ethylene glycol (EG). Pure and mixed gas absorption experiments were conducted to explore the effects of various anions and cations of ILs, the molar ratio of IL to silver salt, the EG proportion on absorption performance, and recycling of absorbents. Due to the synergy between ILs, EG, and Ag+, the absorption of C2H4 in [Emim][BF4]/AgBF4/EG (2:1:0.1) is up to 101.75 mg/g (2.17 mol C2H4/mol Ag+), which is the highest value of IL absorbents reported so far, and the highest selectivity is 37.8. Furthermore, the cyclic stability kept constant after five cycles of absorption–desorption. The interaction mechanism of Ag-ILs was studied by NMR and FTIR spectroscopies. ILs and EG synergistically weaken the electrostatic effect between the anion and cation of AgBF4 and increase the amount of active silver to enhance the absorption of C2H4. These task-specific Ag-ILs are expected to be a new medium with commercial potential for C2H4/C2H6 separation.

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

A series of innovative branching OPBI composite membranes (OPBI-BTZ-PIL) were created based on benzotriazole side chain grafted OPBI (OPBI-BTZ) and double-bond ionic liquids for vanadium redox flow battery applications. The benzotriazole contained three nitrogen sites, which helped enhance the proton conductivity and low area resistance. The cation in the polymeric ionic liquid in the matrix and the vanadium ion produces the Donnan effect, which reduces vanadium permeability. Moreover, the hydrogen bond cross-linking network formed by the polymeric ionic liquid in the membrane further helps proton transport. The vanadium permeability of OPBI-BTZ10-PIL10 is as low as 1.51 × 10−9 cm2 min−1, which is one 40th of the Nafion117 (62.54 × 10−9 cm2 min−1). Its ion selectivity is up to 2.45 × 106 S min cm−3. The OPBI-BTZ10-PIL10 membrane performs well at 60 mA cm−2, with CE of 94.12% and EE of 86.2%, both of which are higher than the Nafion117 membrane.