Degree Of Quaternization Research Articles

N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan: Synthesis, physicochemical and biological properties

Two samples of N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan (DPCat) with different average degrees of quaternization named as DPCat35 (DQ¯ = 35%) and DPCat80 (DQ¯ = 80%), were successfully synthesized by reacting glycidyltrimethylammonium chloride (GTMAC) with O-palmitoyl chitosan (DPCh) derivative (DS¯ = 12%). Such amphiphilic derivatives of chitosan were fully water-soluble at 1.0 < pH < 12.0 and showed significant electrostatic stability enhancement of a self-assembly micellar nanostructure (100–320 nm) due to its positively-charged out-layer. In vitro mucoadhesive and cytotoxicity essays toward healthy fibroblast cells (Balb/C 3T3 clone A31 cell), human prostate cancer (DU145) and liver cancer (HepG2/C3A) cell lines revealed that the biological properties of DPCat derivatives were strongly dependent on DQ¯. Additionally, DPCat35 had better interactions with the biological tissue and with mucin glycoproteins at pH 7.4 as well as exhibited potential to be used on the development of drug delivery systems for prostate and liver cancer treatment.

Effects of Hydrophobic Modifications on the Solution Self-Assembly of P(DMAEMA-co-QDMAEMA)-b-POEGMA Random Diblock Copolymers.

In this work, the synthesis and the aqueous solution self-assembly behavior of novel partially hydrophobically modified poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethylelene glycol) methyl ether methacrylatetabel) pH and temperature responsive random diblock copolymers (P(DMAEMA-co-Q6/12DMAEMA)-b-POEGMA), are reported. The chemical modifications were accomplished via quaternization with 1-iodohexane (Q6) and 1-iodododecane (Q12) and confirmed by 1H-NMR spectroscopy. The successful synthesis of PDMAEMA-b-POEGMA precursor block copolymers was conducted by RAFT polymerization. The partial chemical modification of the diblocks resulted in the permanent attachment of long alkyl chains on the amine groups of the PDMAEMA block and the presence of tertiary and quaternary amines randomly distributed within the PDMAEMA block. Light scattering techniques confirmed that the increased hydrophobic character results in the formation of nanoaggregates of high mass and tunable pH and temperature response. The characteristics of the aggregates are also affected by the aqueous solution preparation protocol, the nature of the quaternizing agent and the quaternization degree. The incorporation of long alkyl chains allowed the encapsulation of indomethacin within the amphiphilic diblock copolymer aggregates. Nanostructures of increased size were detected due to the encapsulation of indomethacin into the interior of the hydrophobic domains. Drug release studies demonstrated that almost 50% of the encapsulated drug can be released on demand by aid of ultrasonication.

Antibacterial properties of cationic copolymers as a function of pendant alkyl chain length and degree of quaternization

AbstractAntibacterial polymers are promising materials in the fight against bacterial infection which is a vital health problem. Among these materials, cationic (co)polymers with quaternary ammonium groups are of great interest and importance as they interact with the bacterial membrane causing cell death. The antibacterial efficacy can be improved by modifying the pendant alkyl groups and charge density of the polycation. In this study, alkylbromides with different chain lengths were used to obtain quaternized poly(4‐vinylpyridine‐co‐N‐vinylpyrrolidone) (P(4VP‐co‐NVP)) copolymers of various positive charge densities and pendent alkyl chain lengths. While the chemical structures of the produced copolymers were characterized by Fourier transform infrared and 1H NMR spectroscopy, physicochemical properties such as size and zeta potential were measured by dynamic light scattering spectrometry. It was determined that the zeta potentials and hydrodynamic diameters of the samples vary between +10 and +32 mV and 10 and 16 nm, respectively. The antibacterial activity of the copolymers were tested against Escherichia coli and Staphylococcus aureus bacteria by broth microdilution and standard ‘plate’ count methods. The results revealed that the antibacterial activity of the copolymers against Escherichia coli can be successfully adjusted through varying the chain length of the alkylating agent (hydrophobic chains) and the degree of quaternization (positive charge density). © 2020 Society of Chemical Industry

Promising Antifungal Potential of Engineered Non-ionic Surfactant-Based Vesicles: In Vitro and In Vivo Studies.

Fungal keratitis (FK) is a corneal infection caused by different fungal species. It is treated by the topical application of natamycin (NAT). Nevertheless, this approach faces many limitations like toxic effects, frequent dosing, resistance, and patient discomfort. The present research reports the development of trimethyl chitosan (TMC) coated mucoadhesive cationic niosomes by a modified thin-film hydration method. TMC was synthesized using a one-step carbodiimide method and characterized by 1H-NMR and degree of quaternization (53.74 ± 1.06%). NAT, cholesterol (CHOL), span 60 (Sp60), and dicetyl phosphate (DCP) were used to prepare niosomes which were incubated with TMC to obtain mucoadhesive cationic NAT loaded niosomes (MCNNs). MCNNs showed a spherical shape with 1031.12 ± 14.18nm size (PDI below 0.3) and 80.23 ± 5.28% entrapment efficiency. In vitro drug release studies showed gradual drug release from TMC coated niosomes as compared to the uncoated niosomes. MIC assay and disk diffusion assay revealed promising in vitro antifungal potential of MCNNs similar to the marketed formulation. For investigating in vivo performance, ocular retention and pharmacokinetics, ocular irritation, and ulcer healing studies were performed using the rabbit model. Mucoadhesive property and prolonged local drug release improved the safety and efficacy of NAT, suggesting that the developed niosomes could be an emerging system for effective treatment of fungal keratitis.

Cytotoxicity Effects of Water-Soluble Multi-Walled Carbon Nanotubes Decorated with Quaternized Hyperbranched Poly(ethyleneimine) Derivatives on Autotrophic and Heterotrophic Gram-Negative Bacteria.

Oxidized multi-walled carbon nanotubes (oxCNTs) were functionalized by a simple non-covalent modification procedure using quaternized hyperbranched poly(ethyleneimine) derivatives (QPEIs), with various quaternization degrees. Structural characterization of these hybrids using a variety of techniques, revealed the successful and homogenous anchoring of QPEIs on the oxCNTs’ surface. Moreover, these hybrids efficiently dispersed in aqueous media, forming dispersions with excellent aqueous stability for over 12 months. Their cytotoxicity effect was investigated on two types of gram(−) bacteria, an autotrophic (cyanobacterium Synechococcus sp. PCC 7942) and a heterotrophic (bacterium Escherichia coli). An enhanced, dose-dependent antibacterial and anti-cyanobacterial activity against both tested organisms was observed, increasing with the quaternization degree. Remarkably, in the photosynthetic bacteria it was shown that the hybrid materials affect their photosynthetic apparatus by selective inhibition of the Photosystem-I electron transport activity. Cytotoxicity studies on a human prostate carcinoma DU145 cell line and 3T3 mouse fibroblasts revealed that all hybrids exhibit high cytocompatibility in the concentration range, in which they also exhibit both high antibacterial and anti-cyanobacterial activity. Thus, QPEI-functionalized oxCNTs can be very attractive candidates as antibacterial and anti-cyanobacterial agents that can be used for potential applications in the disinfection industry, as well as for the control of harmful cyanobacterial blooms.

Greener approach for synthesis of N,N,N-trimethyl chitosan (TMC) using ternary deep eutectic solvents (TDESs)

N,N,N-trimethyl chitosan (TMC), quaternized hydrophilic derivative of chitosan, has been projected to have wide applications in the pharmaceutical industry owing to its improved solubility at physiological conditions. However, the conventional synthesis of TMC involves toxic organic agents, which complicates its use for biological applications. Moreover, these reactions result into unwanted O-methylation and scission of the parent polymer. In the present study we have addressed these limitations by employing a green approach to synthesize TMC, by using lipase as the biocatalyst and dimethyl carbonate (DMC) as the green methylating agent, in a reaction medium comprising of ternary deep eutectic solvents (TDESs). Synthesis of TMC was carried out by using two different lipases from Burkholderia cepacia and Candida rugosa. The resulting TMC was characterized by using FTIR, 1H NMR, DSC, XRD. Methylation was confirmed by FTIR analysis (-CH at 1666 cm−1) and 1H NMR (?? = 3.3 ppm). DSC study revealed a lower thermal stability of TMC as compared to chitosan. These results indicated the possibility of using DMC as a green methylating agent, along with TDESs as green and sustainable solvents, for lipase catalyzed reactions. TMC was successfully synthesized and exhibited a degree of quaternization of about 12.5%, 15.69%, when synthesized used lipases from Burkholderia cepacia and Candida rugosa, respectively.

Controllable antibacterial and bacterially anti-adhesive surface fabricated by a bio-inspired beetle-like macromolecule

Drug resistance to bacteria becomes an emerging intractable problem, therefore, developing novel antibacterial agents has become urgently needed. Herein, a bio-inspired design strategy was adopted to synthesize a series of beetle-like macromolecule of multiple quaternary ammonium salts (QASs), which was designed with different cationic charge densities and numbers of hexadecane chains by adjusting their different quaternization degree (QD). It was found that the fabricated fabric surface with them exhibited controllable and outstanding antibacterial and bacterially anti-adhesive properties. More importantly, the antibacterial efficiency was demonstrated to be enhanced with the increasing of QD, and related to the zeta potential, and surface tension. Additionally, the proposed bacterially anti-adhesive model of action revealed the “resisting effect” of hydration layer which greatly resisted the adhesion of bacteria.

Anti-staphylococcal activity of quaternized mannan from the yeast Candida albicans

Global increase of antibiotic-resistant pathogens as well as elevated content of drug residues in the foodstuffs and the environment urgently calls for new biocompatible antimicrobial biomaterials. Yeast mannans represent readily available source of biodegradable materials for tailor-made derivatives that could be effective in biomedical applications. Here, antimicrobial properties of quaternized mannans (DSQ 0.12, 0.24, 0.30, 0.62) from Candida albicans against clinical multi-resistant strains of Staphylococcus aureus are confronted with possible cytotoxicity against human cells. As expected, both effects increase with increasing degree of quaternization. However, it is possible to define the “window”, at quaternized mannan with DSQ 0.30 with good anti-microbial effectiveness and low cytotoxicity. This derivative exhibit minimum inhibitory (MIC) and minimum bactericidal (MBC) concentration from 62.5 to 250 μg/mL and demonstrate good biofilm inhibition effect. Also acceptable values were obtained in hemagglutination and hemolytic activity assays and also in cytotoxicity tests on human fibroblasts.

Film Properties and Antimicrobial Efficacy of Quaternized PDMAEMA Brushes: Short vs Long Alkyl Chain Length.

Quaternized poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes bearing quaternary ammonium groups of different alkyl chain lengths (ACLs) were prepared and assessed as biocidal coatings. For the synthesis of the antimicrobial brushes, first well-defined PDMAEMA chains were grown by surface-initiated atom transfer radical polymerization on glass and silicon substrates. Next, the tertiary amine groups of the polymer brushes were modified via a quaternization reaction, using alkyl halides, to obtain the cationic polymers. The polymer films were characterized by Fourier-transform infrared spectroscopy, ellipsometry, atomic force microscopy, and water contact angle measurements. The effect of the ACL of the quaternary ammonium groups on the physicochemical properties of the films as well as the contact killing efficiency of the surfaces against representative Gram-positive and Gram-negative bacteria was investigated. A hydrophilic to hydrophobic transition of the surfaces and a significant decrease of the degree of quaternization of the DMAEMA moieties was found upon increasing the ACL of the quaternization agent above six carbon atoms, allowing the wettability, the thickness, and the pH-response of the brushes to be tuned via a facile postpolymerization, quaternization reaction. At the same time, antimicrobial tests revealed that the hydrophilic polymer brushes exhibited enhanced bactericidal activity against Escherichia coli and Bacillus cereus, whereas the hydrophobic surfaces showed a significant deterioration of the in vitro bactericidal performance. Our results elucidate the antimicrobial action of quaternized polymer brushes, dictating the appropriate choice of the ACL of the quaternization agent for the development of coatings that effectively inhibit biofilm formation on surfaces.

Antibacterial effect of nanometer‐size grafted layer of quaternary ammonium polymer on poly(ether ether ketone) substrate

AbstractOwing to its excellent physicochemical properties, poly(ether ether ketone) (PEEK) has been used clinically for medical implants. However, its surface properties should be improved to further enhance its compatibility with a living organism and infection resistance. Here, we examined the surface construction via a combined process, that is, the self‐initiated photoinduced graft polymerization of N,N‐dimethylaminoethyl methacrylate (DMA) on PEEK substrate followed by polymer quaternization using various bromoalkanes (Q‐PDMA‐g‐PEEK). Using a Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy, the grafting and quaternarization of poly(DMA) (PDMA) on the PEEK substrate was confirmed. The degree of quaternizations was at least 60% even when the various bromoalkanes were reacted. The Q‐PDMA‐g‐PEEK with 1‐bromooctane (BrC8) (C8‐Q‐PDMA‐g‐PEEK) substrate exhibited the highest ζ‐potential of other Q‐PDMA‐g‐PEEK substrates. However, no significant differences were observed in the degree of quaternization, thickness of the polymer layer, and hydrophilicity of all modified PEEK substrates. In addition, from antibacterial test with Escherichia coli, the C8Q‐PDMA‐g‐PEEK substrate exhibited the highest antibacterial rate (80%) among Q‐PDMA‐g‐PEEK substrates examined. Therefore, we concluded that the surface ζ‐potential is the one an important parameter for manufacturing PEEK substrates with bactericidal properties.

Enhancement of alkaline conductivity and chemical stability of quaternized poly(2,6-dimethyl-1,4-phenylene oxide) alkaline electrolyte membrane by mild temperature benzyl bromination.

A series of quaternized polyphenylene oxide (QPPO) based alkaline electrolyte membranes with different degrees of quaternization were synthesized via a benzyl bromination method at mild temperature (75 °C). Quite a high hydroxide conductivity under the reduced water uptake and swelling was exhibited by this method. When the degree of bromination measured from 1H NMR analysis was 30%, the corresponding hydroxide ion conductivity was 0.021 S cm−1. The chemical stability of the QPPO membranes was excellent, showing only 3% weight loss in 3 M NaOH solution during 1 month. The fuel cell performance test under H2/O2 exhibited the power density of 77 mW cm−2 and the current density of 190 mA cm−2 at 70 °C. Such excellent properties of QPPO membranes resulted from the achievement of the quaternization at the benzyl position, specifically.

Single-Step Methylation of Chitosan Using Dimethyl Carbonate as a Green Methylating Agent.

N,N,N-Trimethyl chitosan (TMC) is one chitosan derivative that, because of its improved solubility, has been studied for industrial and pharmaceutic applications. Conventional methods for the synthesis of TMC involve the use of highly toxic and harmful reagents, such as methyl iodide and dimethyl sulfate (DMS). Although the methylation of dimethylated chitosan to TMC by dimethyl carbonate (DMC, a green and benign methylating agent) was reported recently, it involved a formaldehyde-based procedure. In this paper we report the single-step synthesis of TMC from chitosan using DMC in an ionic liquid. The TMC synthesised was characterised by 1H NMR spectroscopy and a functionally meaningful degree of quaternisation of 9% was demonstrated after a 12-h reaction time.

Trimethylchitosan hydrochloride obtained from lobster carapace chitin on a bench scale

Starting from the chitin obtained from the lobster carapace, chitosan was obtained. This polymer, due to its high biodegradability, biocompatibility and mucoadhesivity, has a wide use in the pharmaceutical and food industry. Currently, it has great importance in the development of biomaterials for the regeneration of bone and cartilaginous tissues. However, its applications are limited by the insolubility at pH greater than 6. To increase its solubility, different methodologies have been reported. The intensive methylation of the chitosan has been one of the methodologies that have been studied in the last years, generating the N,N,N-trimethylchitosan. This molecule has the characteristic of having permanent positive charges in the chain as a consequence of the quaternization of the amino groups present in the structure of chitosan. Previous studies showed the influence of the agitation rate and the reaction time on the methylation process of the chitosan, using as an alkylating agent the dimethyl sulfate. This allowed to establish a technological process to transform the chitosan. The aim of this work was to obtain N,N,N-trimethylchitosan chloride from chitosan obtained chitin from lobster carapace bench scale. Infrared spectroscopy, Energy dispersive X-ray spectrometry, Nuclear Magnetic Resonance and Intrinsic viscosity were used to characterize the product obtained. The results of the analysis by Infrared spectroscopy, Energy dispersive X-ray spectrometry and Nuclear Magnetic Resonance showed that the methylation process of the chitosan proposed in this work was effective to obtain the desired product. The degree of quaternization, degree of dimethylation and degree of acetylation were 49.2%, 57.5% and 13.3%, respectively. While the value of the intrinsic viscosity [ɳ] of the sample was 78.5 cm3/g. The results corroborate the possibility of modifying chitosan by applying the methodology proposed in this work.

Enhanced monovalent selectivity of cation exchange membranes via adjustable charge density on functional layers

Electrodialysis (ED) technique is a typical and promising membrane process, for applications like water treatment and ion separation. Especially, the separation between monovalent and multivalent cations is a current central issue in many industries and academic researches. Herein, a series of novel cation exchange membranes were prepared from quaternized polyaniline modified sulfonated polyphenyl sulfone (SPPSU) by in-situ polymerization-deposited polyaniline followed by quaternizing with methyl iodide. Restricted divalent cation penetration and regulated monovalent cation transport were achieved by elevating the kinetic effect of electrostatic repulsion and narrowing water channel. Importantly, positive charge density of modification layer could be adjusted by controlling the degree of quaternization, which was accompanied by the change of water channel. When evaluated in a simulated mixed salt system (Mg2+/Na+ and Mg2+/Li+), the optimal quaternized polyaniline membrane exhibited a higher perm-selectivity (PNaMg=4.1, PLiMg=1.75) than initial polyaniline modified cation exchange membrane (PNaMg=0.8, PLiMg=0.75), and commercial monovalent-selective cations exchange membrane CIMS (PNaMg=3.56, PLiMg=1.11). This presented strategy is straightforward and effective, demonstrating the effect of surface positive charge layer on perm-selectivity.

Electro-nanofiltration membranes with positively charged polyamide layer for cations separation

High performance and low-cost monovalent cation perm-selective membranes (MCPMs) are extremely desirable since the widespread demand for monovalent/multivalent cations separation. Herein, we developed a simple fabrication method for the preparation of electro-nanofiltration membranes (ENFMs), which were used as MCPMs for cations separation. The ultra-thin polyamide layer of ENFMs could offer selective channels for the transport of monovalent cations. Meanwhile, the positive charges in the polyamide layer act as useful barriers to divalent cations via electrostatic repulsion. The results show that the ENF-Q3 membrane with the highest quaternization degree owns outstanding perm-selectivity for Li+/Mg2+ system (PMg2+Li+=11.3), which is 7 times greater than that of the commercial CSO membrane, and high Li+ flux (JLi+=5.79×10-8mol·cm-2·s-1) at the current density of 10 mA cm−2. Moreover, the ENFMs exhibit high limiting current density and excellent long-term stability, indicating that the developed strategy is promising to scale up for industrial applications.

A multifunctional gelatine–quaternary ammonium copolymer: An efficient material for reducing dye emission in leather tanning process by superior anionic dye adsorption

Leather wastewater is one of the most polluting industrial emissions. The efficiency of wastewater remediation is limited by its complex composition. Herein, a novel strategy for designing modified gelatine with higher degree of quaternization (MG-2) is presented. The higher degree of quaternization allows sufficient adsorption of dyes in the tanning process. It is an in situ, environmentally friendly, and innovative strategy to limit dye emissions and can circumvent the subsequent waste management. Dyes such as Direct Purple N and Acid Black 24 could be adsorbed completely within 5 min by the MG-2 film formed from MG-2 solution. In addition, a remarkable efficiency in removing Acid Red 73, Golden Orange G, and Acid Orange II (>96.1% removal rates) was achieved within 30 min. The adsorption equilibrium data suggested that the adsorption capacity was positively correlated to the concentration of MG-2. When Acid Orange II and MG-2 were used in the industrial re-tanning process, the residual dye concentration in wastewater was only 23.1 mg L−1, indicating that MG-2 is a promising re-tanning agent for adsorbing dyes in the leather tanning process.

Graphene oxide modified porous P84 co-polyimide membranes for boron recovery by bipolar membrane electrodialysis process

Composite anion-exchange membranes with porous structures have been successfully prepared by incorporating quaternized graphene oxide (QGO) into P84 co-polyimide, and then undergoing the phase inversion, amination and quaternization processes. The membranes’ porous structures can be readily adjusted by the category of non-solvent during the phase inversion process. Large finger-like voids are present in the lower parts of the membrane cross sections by using water or 50% isopropanol aqueous solution, which facilitate the entrance of polyethylenimine chains into the membrane matrix, leading to higher degree of amination and quaternization. The incorporation of QGO does not influence the membrane morphology obviously, but can further enhance the ion exchange capacity (1.23–1.65 mmol/g) and decrease the membrane area resistance (1.6–1.9 Ω cm2).The QGO-P84 composite membranes are used in bipolar membrane electrodialysis (BMED) for the removal of boron from synthetic model solutions (Na2B4O7·10H2O, 1000 mg B/L). The finger-like pores decrease the steric resistance of boron transport, while the incorporation of QGO improves the membrane electro-chemical properties and thus the BMED performances. The separation efficiency is 76.6% after running 3 h under 30 V, the current efficiency is 94.9% and the energy consumption is 26.16 kW h/kg by using the optimal composite membrane. The BMED performances are better than those of commercial membrane CJMA-3 (separation efficiency of 51.6%, current efficiency of 81.2%, and energy consumption of 30.56 kWh/kg). Hence, the QGO-P84 composite membranes are effective for removal and recovery of boron from aqueous solution through BMED method.

Spontaneous Degrafting of Weak and Strong Polycationic Brushes in Aqueous Buffer Solutions

Polymers grafted to substrates have traditionally been considered stable because of the covalent bonds that hold the polymers attached to the substrate. However, several recent reports have indicated that grafted polymers may detach from substrates under specific conditions. In this work, we report on a systematic study of polymer degrafting involving polycationic brushes with different degrees of quaternization (DQ, mol %), which have been incubated in three different buffer solutions (pH 4, 7.4, and 9) with the same ionic strength of 0.05 M. We have varied the molecular weight (MW) and grafting density (σ) of the polymer brushes using a combinatorial setup to examine the effect of MW, σ, and DQ on polymer degrafting. Furthermore, we explored the effect of the bonding environment at the base of the initiator (mono- vs. tri-functional) of the grafted polymer layer at the substrate on the overall stability of polymer brushes on the substrate. The two major findings in this paper are (1) degrafting of polyc...

Main‐chain poly(1,2,3‐triazolium hydroxide)s obtained through AA+BB click polyaddition as anion exchange membranes

AbstractA series of aromatic poly(1,2,3‐triazolium iodide)s were synthesized by step growth polymerization of dipropargyl bisphenol A with aliphatic and aromatic diazides followed by quantitative or partial N‐alkylation of the main‐chain 1,2,3‐triazole groups using iodomethane. After characterization by 1H NMR spectroscopy, SEC and DSC the corresponding self‐standing membranes were obtained by hot pressing. Poly(1,2,3‐triazolium iodide) membranes were converted to the corresponding hydroxide‐containing membranes by anion exchange. Structure–property correlations are discussed based on the evolution of water uptake and ionic conductivity with respect to the ionic exchange capacities of the different materials having distinct chemical structure, quaternization degree and counter‐anion structure. Poly(1,2,3‐triazolium hydroxide) anion exchange membranes exhibit water uptakes below 150% and ionic conductivity in the hydrated state up to 4 mS cm−1 for ionic exchange capacities up to 3.2 meq g−1. © 2019 Society of Chemical Industry

Cyclodextrin templated nanoporous anion exchange membrane for vanadium flow battery application

A β-cyclodextrin (β-CD) based template method is proposed for fabricating high performance nanoporous anion exchange membranes for vanadium flow batteries (VFBs). The β-CD template can be uniformly dispersed in hydroxyl modified polysulfone precursor membrane with a low degree of quaternization; removal of the template will result in the formation of AEMs with well controlled pore structure. This new template method is advantageous due to the hydrogen bonding between the β-CD and polymer so that aggregation of β-CD in the membrane can be minimized. The well dispersed β-CD is beneficial for fabricating porous AEM with small pores, and further for selective transport of protons and anions in the battery. The fabricated porous AEM has low IEC, high conductivity and low vanadium ions permeability. The VFB employing such a membrane showed a coulombic efficiency of 99% and an energy efficiency of 80% at 120 mA cm-2. This work demonstrates the synergistic effect of nanopore and imidazolium cation for high performance VFB membrane fabrication.