Imidazolium Bromide Research Articles

Stimuli-Responsive Vesicles and Hydrogels Formed by a Single-Tailed Dynamic Covalent Surfactant in Aqueous Solutions

Controlling the hierarchical self-assembly of surfactants in aqueous solutions has drawn much attention due to their broad range of applications, from targeted drug release, preparation of smart material, to biocatalysis. However, the synthetic procedures for surfactants with stimuli-responsive hydrophobic chains are complicated, which restricts the development of surfactants. Herein, a novel single-tailed responsive surfactant, 1-methyl-3-(2-(4-((tetradecylimino) methyl) phenoxy) ethyl)-3-imidazolium bromides (C14PMimBr), was facilely fabricated in situ by simply mixing an aldehyde-functionalized imidazolium cation (3-(2-(4-formylphenoxy) ethyl)-1-methyl imidazolium bromide, BAMimBr) and aliphatic amine (tetradecylamine, TDA) through dynamic imine bonding. With increasing concentration, micelles, vesicles, and hydrogels were spontaneously formed by the hierarchical self-assembly of C14PMimBr in aqueous solutions without any additives. The morphologies of vesicles and hydrogels were characterized by cryogenic transmission electron microscopy and scanning electron microscopy. The mechanical properties and microstructure information of hydrogels were demonstrated by rheological measurement, X-ray diffraction, and density functional theory calculation. In addition, the vesicles could be disassembled and reassembled with the breakage and reformation of imine bonds by adding acid/bubbling CO2 and adding alkali. This work provides a simple method for constructing stimuli-responsive surfactant systems and shows great potential application in targeted drug release, drug delivery, and intelligent materials.

Physicochemical and catalytic behavior of binary mixtures of n-alkyl imidazolium bromide ionic liquids with poly (ethylene glycol)-400: Application of flory statistical theory

In this work, Flory statistical theory is employed to predict the important physicochemical properties namely density, isothermal compressibility, internal pressure, coefficient of volume expansion, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter and polarity index for three binary mixtures of PEG-400 + [CnMim][Br], where n=4, 6, and 8 at different temperatures (T= 298.15 K, 308.15 K, and 318.15 K). Furthermore, the applicability of Flory statistical theory to predict certain physicochemical properties has been verified. Excess properties viz., excess enthalpy, excess Gibbs free energy, and excess entropy are also determined for these binary mixtures. The variation of energy of vaporization, heat of vaporization, solubility parameter and excess parameters are used to analyze the catalytic behavior and prevalent molecular interactions of these mixtures.

Colloidal dispersions of cobalt ferrite nanoparticles in EMIM TFSI, propylene carbonate and their mixtures

Liquid thermocells are promising devices for the recovery of low-grade waste heat and its conversion into electricity. The present study proposes dispersing charged magnetic nanoparticles in liquids to improve thermoelectric conversion, due to their thermodiffusive and magnetic properties. Core@shell cobalt ferrite@maghemite nanoparticles (NPs) of various sizes with three different kinds of coatings are tested for dispersion in EMIM TFSI (ethyl-methylimidazolium bistriflimide), an ionic liquid (IL) of high electrical conductivity. Among the tested ligands, PAC6MIM±Br− (1-(6-hexylphosphonate) 3-methyl imidazolium bromide) emerges as the most efficient due to its phosphonic group. This ligand leads to dispersions of clusters of a few dozen NPs in water and a few NPs in EMIM TFSI. For improving both the viscosity and the electrical conductivity, dispersions in binary mixtures of propylene carbonate (PC), a polar medium, and EMIM-TFSI are further investigated with the sample based on NPs of ∼ 9 nm diameter. Through a pumping and heating procedure, stable dispersions are obtained with a subsequent reduction of the size of the NP clusters, down to 1 to 2 NPs in EMIM TFSI and a few NPs in PC and their binary mixtures. The mixture with an IL mole fraction ∼0.2–0.3 and maximal electrical conductivity is a promising candidate for further thermoelectric investigations.

Mechanochemical Synthesis of Corannulene Flanked N-heterocyclic Carbene (NHC) Precursors and Preparation of Their Metal Complexes.

The synthesis of new compounds is an important pillar for the advancement of the field of chemistry and adjacent fields. In this regard, over the last decades huge efforts have been made to not only develop new molecular entities but also more efficient sustainable synthetic methodologies due to the increasing concerns over environmental sustainability. In this context, we have developed synthetic routes to novel corannulene flanked imidazolium bromide NHC precursors both in the solid-state and solution phases. Our work presents a comprehensive comparative study of mechanochemical routes and conventional solution-based methods. Green metrics and energy consumption comparison were performed for both routes revealing ball-milling generation of these compounds to be an environmentally greener technique to produce such precursors compared to conventional solvent-based methods. In addition, we have demonstrated proof-of-concept of the herein reported corannulene flanked NHCs to be robust ligands for transition metals and their ligand substitution reactions.

An inclusive comparison regarding aggregation of surface active ionic liquid and conventional surfactant with a cationic dye Acridine Red exposed in view of spectroscopic and theoretical study

The investigation was conducted on the interaction of acridine red (AR) with sodium dodecyl sulfate (SDS) and 1-butyl-3-methyl imidazolium octyl sulfate (BMImOS) in both premicellar and post micellar concentrations. The interaction between AR and room temperature ionic liquid (RTIL) 1-butyl-3-methyl imidazolium bromide (BMImBr) was studied to understand the effect of imidazolium cation on micellization. Spectroscopic experiments, such as UV–visible absorption spectroscopy, steady-state fluorescence spectroscopy, time-resolved fluorescence spectroscopy, and dynamic light scattering, have been introduced. Various important parameters like spectral shifts, anisotropy, and aggregation number have been determined spectroscopically. However, a fresh insight into density functional theory calculations has also been provided. The observed results have been explained in terms of the aggregation behavior of the amphiphiles. A prominent redshift accompanied by a change in intensity is observed in the presence of surfactant and SAIL. However, in the case of BMImBr, no such spectral shift has been observed; only a decrease in spectral intensity highlights the quenching ability of the imidazolium cation. Average lifetime also provides some additional information regarding the difference in the formation of aggregates by SDS and BMImOS, which is further established from particle size density obtained from DLS. The salt like role of 1-butyl-3-methyl imidazolium cation also has been logically explained by anisotropy measurement and the determination of aggregation number. Using Gauss View 5.0 and Gaussian 09 package, the energy of optimization of each set of amphiphiles along with dye has been determined to follow the interaction at the molecular level. TDDFT calculations have also been performed to determine the structure of HOMO and LUMO.

Imidazolium bromide substituted magnesium phthalocyanine polymers: New promising materials for CO2 conversion

The conversion of CO2 with epoxides into the corresponding cyclic carbonates represents a green approach to transform a waste into value-added products. To promote this conversion, a catalyst in needed. This study presents the synthesis of two cross-linked materials composed of magnesium phthalocyanine and imidazolium bromide moieties: MgPc-BIBI-Br and MgPc-SIBI-Br. Magnesium phthalocyanines are cost-effective and versatile catalysts, synthesized in high yield from low-cost precursors and can be easily modified for specific needs. Imidazolium bromide groups play a crucial role as well, acting as a nucleophile source essential to promote the ring-opening process of the epoxide. The materials have been extensively characterized through analytical and spectroscopic techniques and tested as catalysts in the conversion of epichlorohydrin into 4-chloromethyl-1,3-dioxalan-2-one. They both achieved excellent catalytic performance (maximal TON values of 3070 for MgPc-SIBI-Br and 1903 for MgPc-BIBI-Br) and recyclability (both recyclable at least for 4 cycles). The reported results represent an improvement if compared to similar materials already reported in the literature in which the addition of external nucleophilic species (e.g. TBAB, BMIM-Br, etc.) is needed. To the best of our knowledge, this work is the first example in which imidazolium bromide and magnesium phthalocyanine moieties are combined in bifunctional polymeric materials that convert CO2 into cyclic carbonates via heterogeneous catalysis.

Density functional theory and enzyme studies support interactions between angiotensin receptor blockers and angiotensin converting enzyme-2: Relevance to coronavirus 2019

The binding affinities and interactions between eight drug candidates, both commercially available (candesartan; losartan; losartan carboxylic acid; nirmatrelvir; telmisartan) and newly synthesized benzimidazole-N-biphenyltetrazole (ACC519T), benzimidazole bis-N,Nʹ-biphenyltetrazole (ACC519T(2) and 4-butyl-N,N-bis([2-(2H-tetrazol-5-yl)biphenyl-4-yl]) methyl (BV6), and the active site of angiotensin-converting enzyme-2 (ACE2) were evaluated for their potential as inhibitors against SARS-CoV-2 and regulators of ACE2 function through Density Functional Theory methodology and enzyme activity assays, respectively. Notably, telmisartan and ACC519T(2) exhibited pronounced binding affinities, forming strong interactions with ACE2′s active center, favorably accepting proton from the guanidinium group of arginine273. The ordering of candidates by binding affinity and reactivity descriptors, emerged as telmisartan > ACC519T(2) > candesartan > ACC519T > losartan carboxylic acid > BV6 > losartan > nirmatrelvir. Proton transfers among the active center amino acids revealed their interconnectedness, highlighting a chain-like proton transfer involving tyrosine, phenylalanine, and histidine. Furthermore, these candidates revealed their potential antiviral abilities by influencing proton transfer within the ACE2 active site. Furthermore, through an in vitro pharmacological assays we determined that candesartan and the BV6 derivative, 4-butyl-N,N0-bis[20-2Htetrazol-5-yl)bipheyl-4-yl]methyl)imidazolium bromide (BV6(K+)2) also contain the capacity to increase ACE2 functional activity. This comprehensive analysis collectively underscores the promise of these compounds as potential therapeutic agents against SARS-CoV-2 by targeting crucial protein interactions.

Imidazolium bromide based dual-functional redox mediator for the construction of dendrite-free Li-CO2 batteries

Rechargeable lithium-carbon dioxide (Li-CO2) batteries have emerged as a highly promising approach to simultaneously address energy shortages and the greenhouse effect. However, certain limitations exist in Li-CO2 batteries like high charge overpotential and unstable Li metal interface, which adversely affect the energy efficiency and cycling life. The incorporation of soluble redox mediators (RMs) has proven effective in enhancing the charge transfer between lithium carbonate (Li2CO3) and cathode, thereby substantially reducing the charge overpotential. Nevertheless, the severe shuttle effect of RMs results in the reactions with Li anode, not only exacerbating the corrosion of Li anode but also leading to the depletion of RMs and electrical energy efficiency. In this work, an organic compound containing large cation group, 1-ethyl-3-methylimidazole bromide (EMIBr) is proposed as the defense donor RM for Li anode in Li-CO2 batteries to address the above problems simultaneously. During charging, Li2CO3 oxidation kinetics can be accelerated by bromide anion pair (Br3−/Br−). Meanwhile, the cations (EMI+) are preferentially adsorbed around the protruding tips of Li anode through electrostatic interaction driven by surface free energy, forming protective layers that effectively inhibit further Li deposition at these tips, which is verified by DFT calculations. Additionally, Li dendrites growth is inhibited by the electrostatic repulsion of polar groups in EMIBr, resulting in uniform Li deposition. Consequently, a lower overpotential (∼1.17 V) and a longer cycle life (∼200 cycles) have been obtained for Li-CO2 battery incorporating EMIBr.

Ionic Liquid Modified Fe-Porphyrinic Metal-Organic Frameworks as Efficient and Selective Photocatalysts for CO2 Reduction.

Porphyrin-based metal-organic frameworks (MOFs) are ideal platforms for heterogeneous photocatalysts toward CO2 reduction. To further explore photocatalytic MOF systems, it is also necessary to consider their ability to fine-tune the microenvironments of the active sites, which affects their overall catalytic operation. Herein, a kind of ionic liquid (IL, here is 3-butyric acid-1-methyl imidazolium bromide, BAMeImBr) was anchored to iron-porphyrinic Zr-MOFs with different amounts to obtain ILx@MOF-526 (MOF-526 = Zr6O4(OH)4(FeTCBPP)3, FeTCBPP = iron 5,10,15,20-tetra[4-(4'-carboxyphenyl)phenyl]-porphyrin, x = 100, 200, and 400). ILx@MOF-526 series was designed to investigate the effects of the microenvironmental and electronic structural modification on the efficiency and selectivity of the photochemical reduction of CO2 after introducing IL fragments. Compared to parent MOF-526, the production and selectivity of CO were greatly improved in the absence of any photosensitizer under visible light by the ILx@MOF-526 series. Among them, the CO yield of IL200@MOF-526 was up to 14.0 mmol g-1 within 72 h with a remarkable CO selectivity of 97%, which is superior to that of MOF-526 without BAMeIm+ modification and other amounts of BAMeIm+ loaded. Furthermore, density functional theory calculations were performed to study the mechanism of the CO2 reduction.

Removal of diclofenac sodium from aqueous solution using different ionic liquids functionalized tragacanth gum hydrogel prepared by radiation technique

Diclofenac sodium (DCF) was reported as an important emerging environmental pollutant and its removal from wastewater is very urgent. In this study, different alkyl substituted ionic liquids (1-alkyl −3-vinyl- imidazolium bromide [CnVIm]Br, n = 4, 6, 8, 10, 12) functionalized tragacanth gum (TG-CnBr) are prepared by radiation induced grafting and crosslinking polymerization. The adsorption behaviors of ionic liquids functionalized tragacanth gum for diclofenac sodium from aqueous solutions are examined. The adsorption capacity of TG-CnBr for diclofenac sodium increases with the increasing of alkyl chain length of the imidazolium cation and the hydrophobicity of the hydrogels. The maximum adsorption capacity by TG-C12Br for diclofenac sodium at 30, 40 and 50 °C were 327.87, 310.56 and 283.29 mg/g, respectively. The adsorption of TG-C12Br towards diclofenac sodium was little decreased with NaCl increasing. The removal efficiency was still remained 94.55 % within 5 adsorption-desorption cycles by 1 M HCl. Also, the adsorption mechanism including electrostatic attraction, hydrophobic interaction, hydrogen bonding, and π − π interaction was proposed.

Experimental and in silico insights: interaction of dimethyl sulphoxide with 1-hexyl-2-methyl imidazolium bromide/1-octyl-2-methyl imidazolium bromide at different temperatures.

Ionic liquids have gained attention as 'designer solvents' since they offer a broad spectrum of properties that can be tuned by altering the constituent ions. In this work, 1-alkyl-2-methyl imidazolium-based ionic liquids with two different alkyl chains (alkyl = hexyl and octyl) have been synthesized and characterized. Since the binary mixture of ionic liquids with molecular solvents can give rise to striking physicochemical properties, the interaction of the synthesized room temperature ionic liquids, 1-hexyl-2-methyl imidazolium bromide [HMIM][Br]/1-octyl-2-methyl imidazolium bromide [OMIM][Br] with DMSO has been examined through density and specific conductance at T = (303.15, 308.15, 313.15 and 318.15) K under atmospheric pressure. The obtained molar volume and excess molar volume are fitted to the Redlich-Kister polynomial equation, and the standard deviation is noted. The positive excess molar volume at elevated temperatures indicates volume expansion due to the mutual loss of dipolar association and differences in the sizes and shapes of the constituent molecules. To have a better understanding of the reactivity and efficacy of 1-hexyl-2-methyl imidazolium bromide and 1-octyl-2-methyl imidazolium bromide with DMSO, the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) correlation function of density functional theory (DFT) has been used. The ORCA Program version 4.0 calculates the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy. The effective reactivities of both the compounds that showed an energy band gap (ΔE), i.e., the difference between ELUMO and EHOMO, are 7.147 and 8.037 kcal mol-1.

Fully exploited imidazolium bromide for simultaneous resolution of cathode and anode challenges in zinc–bromine batteries

An imidazolium bromide is developed to simultaneously tackle the challenges of the bromine cathode and the Zn anode in Zn–Br2 batteries.

Ionothermal synthesis of ZSM-5/AlPO4-5 composite zeolites and their catalytic performances in the methanol-to-olefin reaction

Composite zeolites, specifically ZSM-5/AlPO4-5 ([E]-Z5/Al5, [B]-Z5/Al5 and [H]-Z5/Al5), were prepared using tri-substituted imidazolium bromide ionic liquids (ILs). The ILs used were 1-ethyl-2,3-dimethylimidazolium bromide ([EMMIM]Br), 1-butyl-2,3-dimethylimidazolium bromide ([BMMIM]Br) and 1-hexyl-2,3-dimethylimidazolium bromide ([HMMIM]Br). The structure, morphology and acidity of the composite zeolites were analyzed using various techniques, such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), N2 isothermal adsorption-desorption, thermogravimetric analysis (TGA), temperature-programmed desorption of ammonia (NH3-TPD) and nuclear magnetic resonance spectroscopy (NMR). The catalysts obtained demonstrate outstanding performance in the methanol-to-olefin (MTO) reaction, with a catalytic lifetime extended by approximately tenfold and an approximately 10 % increase in the yield of light carbon olefins compared to the traditional hydrothermal Z5/Al5 catalyst. There is a strong relationship between the selectivity and stability of the MTO reaction with the optimized grain size and catalyst acidity.

A mesoporous ionic metal-organic framework decorated by flexible alkyl imidazolium bromide as heterogeneous catalyst for efficient conversion of CO2 to cyclic carbonates

A mesoporous ionic MOF-based catalyst (Br−)C3H7-Imidazolium-MOF-1 for the cycloaddition of CO2 to epoxides (CCE) was synthesized by template-assisted method, and its composite and structure were determined by FT-IR, PXRD, NMR, SEM, TEM, XPS and N2 adsorption. (Br−)C3H7-Imidazolium-MOF-1, is constructed by Zr6O4(OH)4 clusters and linear dicarboxylic acid ligands covalently modified by flexible alkyl imidazolium groups (1-methylene-3-propyl-imidazolium bromide). By the synergistic effect of Zr4+ Lewis acid sites and Br− nucleophiles, (Br−)C3H7-Imidazolium-MOF-1 shown superior catalytic performance for the cycloaddition of CO2 to epichlorohydrin in the absence of any co-catalyst under mild conditions. Small steric hindrance from the flexible imidazolium groups and rapid mass transport of reactants and products in the mesoporous catalyst acted synergistically to promote this process. A firm bond between the imidazolium bromide and the framework of (Br−)C3H7-Imidazolium-MOF-1 made it a recyclable heterogeneous catalyst. Furthermore, several additional coupling reactions were investigated with other epoxides as substrates.

Existence of Quantum Pharmacology in Sartans: Evidence in Isolated Rabbit Iliac Arteries.

Quantum pharmacology introduces theoretical models to describe the possibility of ultra-high dilutions to produce biological effects, which may help to explain the placebo effect observed in hypertensive clinical trials. To determine this within physiology and to evaluate novel ARBs, we tested the ability of known angiotensin II receptor blockers (ARBs) (candesartan and telmisartan) used to treat hypertension and other cardiovascular diseases, as well as novel ARBs (benzimidazole-N-biphenyl tetrazole (ACC519T), benzimidazole-bis-N,N'-biphenyl tetrazole (ACC519T(2)) and 4-butyl-N,N0-bis[[20-2Htetrazol-5-yl)biphenyl-4-yl]methyl)imidazolium bromide (BV6(K+)2), and nirmatrelvir (the active ingredient in Paxlovid) to modulate vascular contraction in iliac rings from healthy male New Zealand White rabbits in responses to various vasopressors (angiotensin A, angiotensin II and phenylephrine). Additionally, the hemodynamic effect of ACC519T and telmisartan on mean arterial pressure in conscious rabbits was determined, while the ex vivo ability of BV6(K+)2 to activate angiotensin-converting enzyme-2 (ACE2) was also investigated. We show that commercially available and novel ARBs can modulate contraction responses at ultra-high dilutions to different vasopressors. ACC519T produced a dose-dependent reduction in rabbit mean arterial pressure while BV6(K+)2 significantly increased ACE2 metabolism. The ability of ARBs to inhibit contraction responses even at ultra-low concentrations provides evidence of the existence of quantum pharmacology. Furthermore, the ability of ACC519T and BV6(K+)2 to modulate blood pressure and ACE2 activity, respectively, indicates their therapeutic potential against hypertension.

Synergistic mechanism of ternary green corrosion inhibitors for N80 steel in 20 wt% HCl solution: Encapsulation and transportation of vanillin through micelles formed by ionic liquids

The encapsulation and directional transport to iron surface of green and poorly water-soluble vanillin were achieved by self-assembled micelles of ionic liquids formed by 1-hexadecyl-2,3-dimethyl imidazolium bromide and sodium dodecyl benzene sulfonate. The anti-corrosion performance of the system for N80 steel in 20 wt% hydrochloride solution at 90 ℃ was studied by weight-loss method, electrochemical tests, and surface analysis. The reaction activity of corrosion inhibitors and self-assembled film formation mechanism at high temperature were revealed by quantum chemistry and molecular dynamics simulation. The results shows that the system exhibits excellent synergistic corrosion inhibition effect via hydrogen bond, electrostatic interaction, and hydrophobic effect.

New sugar-incorporated N-heterocyclic carbene precursors and their Ag(I) and Pd(II) complexes: Synthesis, characterization, and cytotoxicity studies

In the present work, a new series of sugar-incorporated N-heterocyclic carbene precursors namely 1-(3,4,5-trimethoxybenzyl)-3-[2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-ethyl]imidazolium bromide (7a), 4-methyl-1-(3,4,5-trimethoxybenzyl)-3-[2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-ethyl]imidazolium bromide (7b), 4,5-diphenyl-1-(3,4,5-trimethoxybenzyl)-3-[2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-ethyl]imidazolium bromide (7c), and 1-(3,4,5-trimethoxybenzyl)-3-[2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-ethyl]benzimidazolium bromide (8) were synthesized by the direct reaction of the N-alkylated benzimidazoles with 2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-ethyl bromide. Ag(I)–NHC complexes (9a-c, 10) of the abovementioned precursors were synthesized by in-situ reaction with Ag2O in light-excluded conditions. The transmetallation reaction technique was used to synthesize Pd(II)–NHC complexes (11a-c, 12) by the reaction of [PdCl2(MeCN)2] with corresponding Ag(I)–NHC complexes. All NHC precursors and their corresponding Ag(I) and Pd(II) complexes were spectrally characterized using 1H &13C NMR, and mass spectrometry. Further, Pd(II) complexes were evaluated for their anticancer activity against eight diverse cancer cell lines, namely; Pancreatic Adenocarcinoma (Capan-1), Colorectal Carcinoma (HCT-116), Glioblastoma (LN229), Lung Carcinoma (NCI-H1975), Acute Lymphoblastic Leukemia (DND-41), Acute Myeloid Leukemia (HL-60), Chronic Myeloid Leukemia (K562), and non-Hodgkin Lymphoma (Z138). Standard antineoplastic drugs docetaxel and etoposide were included as reference compounds. Among the tested complexes, complex 11c displayed broad activity against all tested cancer types, albeit at higher concentrations when compared to the reference drugs.

Synthesis of potent MDA-MB 231 breast cancer drug molecules from single step

We have prepared novel potent breast cancer drug molecules from non-toxic and inexpensive method. Column chromatography is not necessary for purification of target molecules. The value of overall atom economy, environmental factor, environmental catalyst and product mass intensity gives additional merits for this synthetic method. Synthesized flexible dimeric imidazolium bromides showed less toxicity and gives excellent anticancer response against normal mammary epithelial cells. Novel dimeric pyridinium bromides showed excellent anticancer response against tested cancer cell lines. In cell cycle, novel flexible dimeric pyridinium bromides showed significant arrest in the G2/M phase by nearly three folds, when compared with control drug. We have studied the targeting epidermal growth factor receptor for all the synthesized flexible amino substituted and methyl substituted dimeric pyridinium bromides.

Histidine-inspired polyacrylonitrile-based adsorbent with excellent hemocompatibility for the simultaneous removal of bacteria and endotoxin in septic blood

Endotoxins (LPS) are components of the cell wall of Gram-negative bacteria that are released when bacterial cell membrane is destroyed, the bacteria and the released LPS have led to serious diseases such as sepsis and septic shock. Histidine functionalized adsorbents have been used to remove LPS, however, the present hemoperfusion adsorbents have drawbacks such as inadequate LPS adsorption capability, high cost of raw material, and so on. Inspired by the structure of histidine and incorporated antibacterial molecules, we synthesize allylamine-modified polyacrylonitrile (PAD)/poly (imidazolium bromide) (PMIBr) composite (PAI) microspheres as hemoperfusion adsorbents. The PAI microspheres show excellent antibacterial ability with high killing efficiency of 98.8% against S. aureus and 95.4% against E. coli. In addition, the adsorption capacity of the microspheres for LPS in PBS is 433.5 EU/g within 3 h, and the LPS concentration could also be reduced from 7.34 EU/mL to below 0.5 EU/mL in the plasma environment. The PAI microspheres exhibit outstanding blood compatibility, antibacterial property and endotoxin removal capability, which have great potential in the treatment of sepsis patients.

Effect of aromatic ring on surface and self‐assembly properties of synthesized heterocyclic‐based surfactants

AbstractHeterocyclic‐based cationic surfactants with dodecyl tail group bridged to the head group either via aromatic ether [3‐(4‐dodecyloxybenzyl)‐1‐methyl‐imidazolium bromide (Ar‐I) and 4‐(4‐dodecyloxybenzyl)‐4‐methyl‐morpholinium bromide (Ar‐M)] or via aliphatic ether [3‐(2‐dodecyloxyethyl)‐1‐methyl imidazolium bromide (Al‐I) and 4‐(2‐dodecyloxyethyl)‐4‐methyl morpholinium bromide (Al‐M)] were synthesized and characterized using different spectral techniques. For the synthesis of Ar‐I and Ar‐M, 4‐hydroxybenzoic acid was esterified initially, followed by O‐alkylation, reduction, bromination and finally quaternization either with 1‐methylimidazole or with 4‐methylmorpholine. For the synthesis of aliphatic analogues (Al‐I and Al‐M), ethylene glycol was initially alkylated, followed by tosylation, bromination and quaternization either with 1‐methylimidazole or with 4‐methylmorpholine. Synthesized surfactants were evaluated for surface and self‐assembly properties. Impact of the presence or absence of phenyl ring bridging the polar head and nonpolar tail of the surfactant and also type of heterocyclic moiety in the head group region on micellization and surface properties such as wetting, foaming and emulsification was studied. Surfactants with the bridged aromatic ether moiety were observed to display lower critical micelle concentration than those with the bridged aliphatic ether moiety irrespective of type of heterocyclic molecule in the head group region. Foam volume and stability of the aromatic ether‐bridged surfactant were observed to be superior to their corresponding aliphatic analogs. Similar trend was observed in stabilizing the emulsion. However, aromatic ether‐bridged surfactant depicted poor wetting ability compared to their aliphatic analog. Aliphatic ether bridged surfactant showed higher aggregation number compared to their aromatic counterparts, but depicted similar micellar core polarity.