Amino Acid Ionic Liquids Research Articles

Amino acid ionic liquid–based magnetic dispersive solid-phase extraction for benzimidazole residue analysis in fruit juice and human serum based on theoretical screening

The theoretical screening and design of green solvents to reduce organic solvents and to develop green and efficient sample pretreatment methods have attracted extensive attention. Here, benzimidazoles (BZDs) with potential reproductive toxicity were used as target compounds, and amino acid ionic liquids (AAILs) were designed and selected via a theoretical calculation. With the functionalized AAIL as monomers, and POSS as the crosslinking agent, novel specific magnetic nanoparticles (Fe3O4@SiO2@MAPs@AAIL-POSS) were prepared and used to develop the magnetic dispersive solid-phase extraction (MDSPE) of trace BZDs from fruit juice and human serum. In the evaluation of the method, Fe3O4@SiO2@MAPs@AAIL-POSS showed specific adsorption, recyclable ability, high adsorption efficiency, a good recovery rate, and a low coefficient of variation. In addition, the adsorption behavior of Fe3O4@SiO2@MAPs@AAIL-POSS on BZDs was verified by investigating the kinetic and thermodynamic of the adsorption process. The study design provides ideas for green rapid detection methods of other food pollutants.

Experimental and theoretical research on the corrosion inhibition of 1-octyl-3-methylimidazolium L-prolinate for copper in 3.5% NaCl solution

An amino acid ionic liquid, namely 1-octyl-3-methylimidazolium L-prolinate ([OMIM]L-pro), was investigated as the corrosion inhibitor of copper in 3.5% NaCl solution through electrochemical techniques, surface analysis and molecular dynamics simulation. The results showed that [OMIM]L-pro was a mixed type inhibitor with a predominantly anodic action for copper in NaCl solution, its inhibition efficiency increased with the increase of concentration, but decreased with rising temperature, the highest inhibition efficiency was up to 97.5%. The adsorption of [OMIM]L-pro on the copper surface was found to follow the Langmuir isothermal equation, and the corrosion kinetic characteristics of copper in the test solution was discussed and analyzed. Moreover, L-prolinate anion was found to play a significant role in the corrosion inhibition performance of [OMIM]L-pro, but there was a synergistic effect between L-prolinate anion and imidazolium cation, which synergistically inhibited the corrosion of copper in NaCl solution. Molecular dynamics simulation data supported the experimental results.

Predictive modeling of antibacterial activity of ionic liquids by machine learning methods

Structural variation and different bioactivity of ionic liquids (ILs) make them highly promising for the development of novel biocides. Application of computational methods to the evaluation of potential antibacterial activity of chemical compounds is a useful, time- and cost-saving tool replacing numerous experimental syntheses. In the present study, quantitative structure–activity relationship (QSAR) modeling is applied to develop models (based on more than 800 data points) aiming to predict the minimal inhibitory concentration (MIC) of ILs against three types of human pathogens – Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The random forest model with the AlvaDesc descriptors in general demonstrates the best performance for all the three types of bacteria and is suggested as a final model. To interpret the final model and determine the most significant descriptors, a SHapley Additive exPlanation (SHAP) method was applied. Six amino acid ILs, which were synthesized for the first time, and five halogenide ionic liquids purchased, all based on 1-alkyl-3methylimidozolium cations with different alkyl chain lengths, C10, C12 and C14, are tested in vitro and used to validate the developed QSAR models. The data sets and developed model are available free of charge at http://ochem.eu/article/147386.

Ultra-stretchable, Antifatigue, Adhesive, and Self-Healing Hydrogels Based on the Amino Acid Derivative and Ionic Liquid for Flexible Strain Sensors

Multifunctional adhesive hydrogels have great potential in flexible wearable materials, smart wearable materials, and biomedical materials. However, the preparation of such hydrogels is still challenging. Here, a P(MArg-FHVI-AA) hydrogel was prepared by copolymerization of an arginine derivative monomer, ionic liquid imidazolium salt derivative monomer, and acrylic acid (AA). Based on multiple weak hydrogen bonds and electrostatic interactions, the hydrogel had the following characteristics: high transparency (>85%), ultra-stretchability (2613%), high elasticity (1000% strain cyclic for 10 times), fatigue resistance (200 cycles under 80% compressive strain), self-healing, good adhesion in air and water (37 and 32 kPa for porcine skin in air and water), and electrical conductivity. When metal ions were added to P(MArg-FHVI-AA) hydrogels, the mechanical properties of the hydrogels were enhanced (tensile strength of 109–352 kPa, stretchability of 1707–1942%), and the hydrogels exhibited stronger adhesion strength (68 kPa for porcine skin), good biocompatibility (99%), impressive antibacterial properties (100% antibacterial effect against Escherichia coli and Staphylococcus aureus), shape memory, fluorescent writing (its fluorescence intensity was 1099% of the initial), and information transfer functions. Furthermore, the P(MArg-FHVI-AA) hydrogel showed real-time performance in monitoring various motions. This work provided an idea for the construction of multifunctional and smart adhesive conductive hydrogel materials, and this hydrogel could be a promising candidate for smart wearable materials, health monitoring, and soft body materials.

Flame retardancy performance and mechanism of polyvinyl alcohol films grafted amino acid ionic liquids with high transparency and excellent flexibility

High transparency performance of polyvinyl alcohol (PVA) films with excellent flexibility plays an important role in wearable devices, solar cells displays and other fields. However, maintaining good transparency is a great challenge to prepare the flame retardancy PVA films. The PVA/L-Aspartic acid phosphate ionic liquid (AAILs) films (PL) with good transparency were firstly designed and prepared relying chemical-bands through sol-gel method. The flame retardancy and transparency performance of PL films were systematically characterized using various methods. The addition of AAILs did not affect the transparency of the PVA films, and the PL films had visible toughness and flexibility. Compared with the PVA films, the transparency and flame retardant performance of PL films were improved and the PL films with UL94 V0 rating and LOI of 30.1% were achieved when AAILs were added to 20.0 wt%. The homogeneous dispersion and high compatibility of AAILs in PVA films can be achieved relying chemical-bands using sol-gel method. The PL films had the high flame retardany performance and excellent flexiblility after the introduction of AAILs, while maintaining the transparency, biocompatibility and biodegradability. It provides a simple and low-cost method for the preparation of environmental-friendly flame retardant PL films.

Intensification of Amino Acid Ionic Liquids with Different Additives for CO2 Capture

Amino acid ionic liquids (AAILs) exhibit prominent merits for CO2 capture including biocompatibility and good stability, but they still suffer from several demerits, such as high viscosity and low molecular utilization. Therefore, it is critical to construct proper systems that can address these problems to enhance CO2 absorption of AAILs. In this work, three types of AAIL absorbent systems, DMEE (2-[2-(dimethylamino) ethoxy] ethanol)–AAIL, H2O–AAIL, and EG (ethylene glycol)–AAIL, are prepared with six AAILs that have different amino acids. The absorption performance of these absorbents is characterized to investigate the reinforcing effects of the additives on the absorption properties of AAILs. With temperatures ranging from 293 to 313 K, the CO2 capture studies on the binary systems reveal that AAILs present better absorption efficiency when their concentrations are 40 or 50 wt %. Based on the zwitterion reaction mechanism model and a thermodynamic model, the interactions of AAILs with H2O, DMEE, and EG systems for absorbing CO2 are discussed, respectively. The results obtained in this work indicate that AAIL–DMEE systems are promising candidates for CO2 capture since the interaction between AAILs and DMEE increases the capacity of AAILs and promotes kinetics.

Amino acid ionic liquids as components of aqueous biphasic systems for L-tryptophan extraction: Experiment and thermodynamic modeling with ePC-SAFT equation of state

Aqueous biphasic systems (ABSs) based on ionic liquids (ILs) have been considered as promising for the extraction, purification and separation of a wide range of substances, including biomolecules. Among the structurally modified ILs, amino acid ILs (AAILs) attract special attention.In this work we obtain systematic experimental data on the partitioning of L-tryptophan in the aqueous mixtures of 1-alkyl-3-methylimidazolium AAILs, [Cnmim]X, with different hydrocarbon chain length (n = 4, 8) and amino acid anions: X = [Leu] (L-Leucinate), [Val] (L-Valinate), [Lys] (L-Lysinate), and inorganic salt (K3PO4). Our results show that the partition coefficients are higher in the ABSs with AAILs than with halide ILs. AAIL with [C8mim]+ cation demonstrate a noticeable specificity of lysinate anions. The obtained new data are discussed in terms of AAIL’s structure. We conclude that hydrogen bonding is likely to play the major role in partitioning of the solute. Taking into account the low toxicity of AAILs, these ABSs have a high potential for the extraction of small biomolecules.Moreover, we found that in the studied ABSs based on chiral AAILs, partitioning of D-tryptophan is equal to that for L-tryptophan.ePC-SAFT is applied for the first time to model liquid-liquid equlibrium in ternary ABSs containing AAILs and partitioning of L-tryptophan. We obtain satisfactory results and conclude that ePC-SAFT is a promising tool for modeling ABSs that contain AAIL and inorganic salt.

Choline amino acid ionic Liquids: A novel green potential lubricant

Given the depletion of global energy and crisis of environmental pollution, the social demand for lubricants concerning green and socioeconomic benefits is becoming stronger. Herein, a series of eco-friendly, non-corrosive and cost-effective choline amino acid ionic liquids ([Ch][AA]) ILs were synthesized. Among the five [Ch][AA] ILs, long-alkyl-chain and guanidyl group-containing ILs display superior wettability, kinematic viscosity and load-carrying property. Regulation of tribological behavior is achieved through the assembly of anionic structure. Additionally, various friction conditions govern the lubrication regime of [Ch][AA] ILs. Concurrently, the friction-heat is predicted according to the thermal-physical properties. Furthermore, lubrication performance of [Ch][AA] ILs is comparable to polyalphaolefin oil (PAO 40) in various lubrication regime, which are attributed to the resulting thermal-physical properties and physical adsorption tribofilms. This work not only perfects the lubricating system of the [Ch][AA] ILs, but also is of great significance to elucidating the applicable conditions of desired [Ch][AA] ILs lubricants.

Density, viscosity and electrical conductivity of four amino acid based ionic liquids derived from l-Histidine, l-Lysine, l-Serine, and Glycine

Amino acid ionic liquids (AAILs), as a kind of renewable and biocompatible ionic liquids, show special properties of strong polarity, strong hydrogen bonding ability, stable chiral center and excellent biodegradability, and share huge application potentials in almost all of the biological, medical, pharmaceutical and biotechnological processes. The investigation of physico-chemical properties of AAILs both in purity and interacting with molecular solvents highly contributes to understanding the huge application potential of AAILs in different fields of the chemical, pharmaceutical and petrochemical industries. This paper synthesized several AAILs of [VilmC3][His], [VilmC3][Lys], [VilmC3][Ser] and [VilmC3][Gly], by using l-Histidine, l-Lysine, l-Serine, and Glycine as anions, respectively. The obtained AAILs were characterized by 1H NMR analysis and TG-DTG analysis. The basic physical properties of density, dynamic viscosity, and conductivity were systemically measured. The apparent molar volume, limiting apparent molar volume, excess molar volume, isobaric expansivity coefficient and apparent molar expansivity were estimated from density. The viscosity deviation, the molar and limiting conductivities were calculated from dynamic viscosity and conductivity, respectively. Various models were used to correlate the experimental data, and the molecular interactions were discussed. The information obtained from this work serves as the basement to the AAILs application.

Thermochemical study of CO2 capture by mesoporous silica gel loaded with the amino acid ionic liquid 1-ethyl-3-methylimidazolium glycinate

A series of composite CO2 sorbents were obtained by placing an amino acid ionic liquid (AAIL) 1-Ethyl-3-methylimidazolium glycine ([Emim][Gly]) into mesoporous silica gel using an impregnation method. The parameters of the porous structure for the silica support and composite sorbents were determined from nitrogen adsorption-desorption isotherms measured at 77 K. The morphology of the materials was studied using field-emission scanning electron microscopy. It was shown that at lower [Emim][Gly] loadings (<50 wt%), the sorption is fast and the dynamic CO2 sorption capacity of the material is proportional to the mass content of the AAIL. At higher [Emim][Gly] loadings (≥50 wt%), the rate of CO2 sorption by the AAIL decreases due to hindered mass transfer. An increase in CO2 concentration in the gas flow leads to a faster sorption and higher CO2 sorption capacity for the AAIL-containing composite. Meanwhile, the integral enthalpy of sorption decreases with increasing CO2 concentration, which can be explained by the greater contribution of physical adsorption/absorption processes to the total CO2 sorption capacity at higher CO2 concentrations. The most promising composite material (40 wt% [Emim][Gly]/SiO2) was tested in consecutive temperature-swing sorption-desorption cycles. It was demonstrated that lowering the regeneration temperature from 100 to 80 °C leads to a decrease in the dynamic sorption capacity of the material, but ensures its stability in the cyclic sorption-desorption process.

Enhancing CO2 absorption with amino acid ionic liquid [N1111][Gly] aqueous solution by twin-liquid film flow: Experimental and numerical study

• The rheological response of [N 1111 ][Gly] aqueous solution during CO 2 capture. • Twin-liquid film behavior with [N 1111 ][Gly] aqueous solution and its mass transfer performance. • Film thickness is reduced and film velocity is improved for high viscosity [N 1111 ][Gly] aqueous solution by twin-liquid film. • Accommodation of the twin-liquid film to fluid viscosity by modulating window dimensions. Tetramethylamine glycine ([N 1111 ][Gly]) (ILs) is a potential substitute for the alcohol amine absorbent. However, its high viscosity restricts industrial CO 2 absorption due to poor mass transfer performance. Surface renewal is the key to enhance interfacial mass transfer for highly viscous fluids. Considering the rheological response of the [N 1111 ][Gly] aqueous solution during CO 2 capture, the twin-liquid film is suggested for the [N 1111 ][Gly] aqueous solution. The behavior of the twin-liquid film has been investigated by flow experiments and numerical simulation. Reduction of film thickness and improvement of surface velocity can be achieved by the interplay between the twin films, which enhances surface renewal frequency. The accommodation of the twin-liquid film to fluid viscosity can be satisfied by modulating window dimensions. The enhanced mass transfer performance of the twin-liquid film with [N 1111 ][Gly] aqueous solution, illustrated by enhanced surface renewal frequency, proves it a feasible way for industrial CO 2 capture.

Mesoporous poly(amino acids) ionic liquid with excellent extraction performance for sunset yellow

The poly amino acid ionic liquid {1-ethyl-3-benzyltriethylammonium alanine P[ETA][Ala]} was synthesized and characterized with Fourier Transform Infrared Spectroscopy (FTIR), Carbon Nuclear Magnetic Spectra(13C NMR), Scanning Electron Microscope (SEM), X-ray (XRD), Brumaire-Emmett-Teller (BET). SEM and BET confirmed that P[ETA][Ala] was a porous material. Under optimized conditions, the linear range of sunset Yellow (SY) was 0.02–20.00 μg mL−1, the limit of detection (LOD) was 0.01 μg mL−1 and the enrichment factor was 11.0 (pre-extraction solution volume/elution volume). The isothermal adsorption and kinetic models were investigated to explain the extraction (adsorption) mechanism of SY on P[ETA][Ala]. This proposed method was successfully applied the analysis of beverage samples with recoveries of 92.0–110.0% and relative standard deviations of 1.1–5.0%.

Ionic liquid-modulated aerobic oxidation of isoeugenol and β-caryophyllene via nanoscale Cu-MOFs under mild conditions

Novel synergistic systems based on Cu-1,3,5-benzenetricarboxylate and ionic liquid are developed for the convenient conversion of renewable olefins, isoeugenol and β-caryophyllene, under very mild conditions (i.e. 313 K and 1 atm O2). Using acidic ionic liquid [C4mim][HSO4] (5.0 mol%) as co-catalyst, Cu3(BTC)2-Lauric acid (LA) afforded high selectivity (95.8%) and excellent yield (86.3%) for vanillin methyl ketone during the aerobic oxidation of isoeugenol. In comparison, 91.1% selectivity for vanillin together with 28.9% conversion of isoeugenol was obtained over Cu3(BTC)2-LA in the presence of amino acid ionic liquid, [C4mim][Ala]. Additionally, 91.3% selectivity and 86.5% yield for β-caryophyllene epoxide were provided by Cu3(BTC)2-LA with the aid of neutral [C4mim]Cl (5.0 mol%), indicating the importance of different types of ILs in tuning the microenvironments of designed Cu3(BTC)2-LA nanosystems. Simultaneously, Cu3(BTC)2-LA/IL showed superior stability during above-mentioned transformations, as verified by TEM, FT-IR and XRD analyses. Insights into the synergistic free radical routes were supported by fluorescence and DRUV-Vis characterizations.

A Systematic Review of Amino Acid-Based Adsorbents for CO2 Capture

The rise of carbon dioxide (CO2) levels in the atmosphere emphasises the need for improving the current carbon capture and storage (CCS) technology. A conventional absorption method that utilises amine-based solvent is known to cause corrosion to process equipment. The solvent is easily degraded and has high energy requirement for regeneration. Amino acids are suitable candidates to replace traditional alkanolamines attributed to their identical amino functional group. In addition, amino acid salt is a green material due to its extremely low toxicity, low volatility, less corrosive, and high efficiency to capture CO2. Previous studies have shown promising results in CO2 capture using amino acids salts solutions and amino acid ionic liquids. Currently, amino acid solvents are also utilised to enhance the adsorption capacity of solid sorbents. This systematic review is the first to summarise the currently available amino acid-based adsorbents for CO2 capture using PRISMA method. Physical and chemical properties of the adsorbents that contribute to effective CO2 capture are thoroughly discussed. A total of four categories of amino acid-based adsorbents are evaluated for their CO2 adsorption capacities. The regeneration studies are briefly discussed and several limitations associated with amino acid-based adsorbents for CO2 capture are presented before the conclusion.

A New Compartmentalized Scale (PN) for Measuring Polarity Applied to Novel Ether-Functionalized Amino Acid Ionic Liquids.

Functionalized and environmentally friendly ionic liquids are required in many fields, but convenient methods for measuring their polarity are lacking. Two novel ether-functionalized amino acid ionic liquids, 1-(2-methoxyethyl)-3-methylimidazolium alanine ([C1OC2mim][Ala]) and 1-(2-ethoxyethyl)-3-methylimidazolium alanine ([C2OC2mim][Ala]), were synthesized by a neutralization method and their structures confirmed by NMR spectroscopy. Density, surface tension, and refractive index were determined using the standard addition method. The strength of intermolecular interactions within these ionic liquids was examined in terms of standard entropy, lattice energy, and association enthalpy. A new polarity scale, PN, is now proposed, which divides polarity into two compartments: the surface and the body of the liquid. Surface tension is predicted via an improved Lorentz-Lorenz equation, and molar surface entropy is used to determine the polarity of the surface. This new PN scale is based on easily measured physicochemical parameters, is validated against alternative polarity scales, and is applicable to both ionic and molecular liquids.

Synthesis, anti-leishmanial screening, molecular docking, and ADME study of 1-amidoalkyl 2-naphthol derivatives catalyzed by amino acid ionic liquid

Synthesis, anti-leishmanial screening, molecular docking, and ADME study of 1-amidoalkyl 2-naphthol derivatives catalyzed by amino acid ionic liquid

Excess properties and activation properties for viscous flow of amino acid ionic liquids with H2O binary mixtures

Amino acid ionic liquids (ILs) 1-butyl-2,3-dimethylimidazolium glycine ([C4Dmim][Gly]), 1-butyl-2,3-dimethylimidazolium alanine ([C4Dmim][Ala]) and 1-butyl-2,3-dimethylimidazolium threonine ([C4Dmim][Thr]) were prepared. Over the temperature from (288.15–318.15) K, the density, surface tension and viscosity for binary system mixtures of ILs with H2O were measured, and excess thermodynamic properties and activation properties for viscous flow of these binary system mixtures were systematically studied. Secondly, the variation trend between excess molar volume (VE)/excess molar surface Gibbs energy (gsE) and mole fraction for ILs + H2O binary system mixtures was investigated. With the increase of mole fraction, the VE and gsE values of binary system mixtures increased firstly and then decreased, and they were positive value, which may be due to the weak chemical interaction between ILs and H2O in the mixture. Furthermore, according to the thermodynamic formula, the Gibbs energy of activation for viscous flow of the relative viscosity (ΔG≠r), activation entropy (ΔS≠r) and activation enthalpy (ΔH≠r) were calculated. Over the entire concentration range, the ΔG≠r values for binary system mixtures of ILs with H2O were negative value, and the result was in good agreement with relative viscosity (ηr).

Cu(II)‐Amino Acid Ionic Liquid Surfactants: Metallovesicles as Nano‐Catalytic Reactors for Cross Dehydrogenative Coupling Reaction in Water

AbstractUtilization of the water as a reaction medium is very challenging due to the organic molecules insolubility in the aqueous medium. Still, self‐assembled structures like micelles and vesicles can act as nanoreactors to perform the organic reactions in water. In our efforts to achieve a chemical reaction in water, we have synthesized sustainable Cu (II) based amino acid (phenylalanine or valine) ionic liquid surfactants [AAC12]2[CuCl4], constructed their metallovesicles, and utilized these as nano‐catalytic reactors for C−C bond formation in the propargyl amines under the oxidative conditions. Aggregation of [AAC12]2[CuCl4] in an aqueous medium was studied using surface tension, pyrene fluorescence, and specific conductivity measurements. TEM and DLS analysis confirmed the formation of metallovesicles. [AAC12]2[CuCl4] metallovesicles acted as multitasking nanoreactors to provide a bio‐based template, water as a solvent, no additional catalyst to perform the reaction, and high yield (up to 94 % in low Cu(II) 0.012 mol%). Furthermore, The retention in the chirality of amino acid is observed in [AAC12]2[CuCl4], which can be a promising approach for one‐pot synthesis of chiral moieties in a greener way for future pharmaceutical manufacturing and other Cu(II) catalyzed reactions.

Application of amino acid ionic liquids for increasing the stability of DNA in long term storage

The structural stability of DNA is important because of its biological activity. DNAs due to their inherent chemical properties are not stable in an aqueous solution, therefore, a long period of storage of DNA at the ambient condition in bioscience is of importance. Ionic liquids (ILs) as interesting alternatives compared to organic solvents and water due to their considerable properties can be used as new agents to increase the stability of DNA for a long period of storage. In this article, molecular dynamics (MD) simulations and quantum chemistry calculations were applied to investigate the effects of amino acid ionic liquids ([BMIM][Ala], [BMIM][Gly], [BMIM][Val], [BMIM][Pro] and [BMIM][Leu]) on the dynamical behavior and the structural stability of calf thymus DNA. Based on the obtained MD results ILs enter into the solvation shell of the DNA and push away the water molecules from the DNA surface. Structural analysis shows that [BMIM]+ cations can occupy the DNA minor groove without disturbing the double-helical structure of DNA. ILs due to strong electrostatic and van der Waals (vdW) interactions with the DNA structure contribute to the stability of the double-helical structure. Quantum chemistry calculations indicate that the interactions between the [BMIM]+ cation and DNA structure has an electrostatic character. Moreover, this cation forms a more stable complex with the CGCG region of the DNA in comparison with AATT base pairs. Overall, the results of this study can provide new insight into the application of ILs for maintaining DNA stability during long-term storage. Communicated by Ramaswamy H. Sarma

Optimization of Poly(ethylene terephthalate) Fiber Degradation by Response Surface Methodology Using an Amino Acid Ionic Liquid Catalyst

Optimization of Poly(ethylene terephthalate) Fiber Degradation by Response Surface Methodology Using an Amino Acid Ionic Liquid Catalyst