Magnetic Ionic Liquid Research Articles

Facile Construction of Magnetic Ionic Liquid Supported Silica for Aerobic Oxidative Desulfurization in Fuel

With the rapid growth in fuel demand, deep desulfurization of fuel oil is vitally necessary for the sake of health and environmental protection. In this work, a kind of magnetic ionic liquid supported silica is prepared by a facile ball milling method, and applied in the aerobic oxidative desulfurization of organosulfurs in fuel. The experimental results indicated that ball milling procedure can increase the specific surface area of samples, which is beneficial to oxidative desulfurization process. Under the optimal reaction conditions, the prepared materials can have an entire removal of aromatic sulfur compounds as well as a good recycling ability. Moreover, the introduction of Fe3O4 did not decline the desulfurization performance, but help the catalyst to be easily separated after reaction.

Liquid-liquid equilibria for (polypropylene glycol 400 based magnetic ionic liquids + inorganic salts) aqueous two-phase systems at 298.15 K

Two polypropylene glycol 400 (PPG400) based temperature-sensitive magnetic ionic liquids were successfully used to construct the temperature-sensitive magnetic ionic liquid aqueous two-phase systems (MILATPs). This temperature-sensitive MILATPs combined temperature-controlled recovery and the advantages of a MILATPs and is showing great potential in the field of extraction and separation. In this work, aqueous two-phase equilibrium data of the temperature-sensitive MILATPs ([HOPPG400BMIM][Tempo-OSO3] + K3PO4/K2CO3/ Na2CO3 + H2O systems and [BMIMPPG400BMIM][Tempo-OSO3]2 + K3PO4/K2CO3/ Na2CO3 + H2O systems) were determined at 298.15 K under 0.1 MPa. Three common empirical equations including Merchuk equation were adopted to fit the experimental binodal data with satisfactory correlation performances. Inorganic salts screening demonstrated that K3PO4 and K2CO3 have better phase-forming ability than Na2CO3. Morever, [HOPPG400BMIM][Tempo-OSO3] has a better phase-forming ability than [BMIMPPG400BMIM][Tempo-OSO3]2. Subsequently, tie line data for systems containing K3PO4 or K2CO3 were determined and correlated by two empirical equations with satisfactory correlation performances. Furthermore, the temperature- controlled recovery of temperature-sensitive magnetic ionic liquid was ideally realized simply by heating. All these experimentally measured liquid–liquid equilibrium data and the theoretical correlations can provide valuable reference for future application in the field of extraction and separation.

Tungstate supported on magnetic ionic liquid-modified graphene oxide as an efficient and recyclable catalyst for the selective oxidation of sulfides

An effective and recyclable catalyst based on tungstate ion immobilization on magnetic ionic liquid modified graphene oxide (WO4@Fe3O4/GO-IL) has been synthesized in this research. The catalyst was characterized by various techniques such as Raman spectroscopy, X-ray diffraction, thermogravimetric analysis, electron microscopy transmission and scanning, and vibrating sample magnetometer. Also, for the selective oxidation of sulfides to the corresponding sulfoxides, the as-synthesized catalyst was investigated. Additionally, the WO4@Fe3O4/GO hybrid was used to study the role of ionic liquid in this transformation and, the observed yield of methyl phenyl sulfoxide was remarkably inferior. Also, by using an external magnet, the catalyst can be quickly retrieved and recycled successfully in five following reaction cycles without any significant reduction in activity and selectivity of the catalyst.

An overview of magnetic ionic liquids: From synthetic strategies to applications in microextraction techniques.

Remarkable progress has been achieved in the application of magnetic ionic liquids in microextraction-based procedures. These materials exhibit unique physicochemical properties of ionic liquids featuring additional responses to magnetic fields by incorporating a paramagnetic component within the chemical structure. This intriguing property can open new horizons in analytical extractions because the solvent manipulation is facilitated. Moreover, the tunable chemical structures of magnetic ionic liquids also allow for task-specific extractions that can significantly increase the method selectivity. This review aimed at providing an up-to-date overview of articles involving synthesis, physicochemical properties, and applications of magnetic ionic liquids highlighting recent developments and configurations. Moreover, a section containing critical evaluation and future trends in magnetic ionic liquid-based extractions is included.

Removal and recovery of triphenylmethane dyes from wastewater with temperature-sensitive magnetic ionic liquid aqueous two-phase system

In this report, temperature-sensitive magnetic ionic liquids (MILs) were discovered for the first time. Two polypropylene glycol 400 (PPG400) based temperature-sensitive MILs were synthesized, characterized and successfully applied to construct the first reported temperature-sensitive magnetic ionic liquid aqueous two-phase system (MILATPs). To the best of our knowledge, this proposed temperature-sensitive MILATPs combined the advantages of rapid extraction, organic solvent free for the whole process, magnetic separation and thermo-recovery of MIL in a separation process for the first time. Temperature-sensitive MILATPs were successfully applied for the removal and recovery of three triphenylmethane dyes from wastewater. Phase behaviors and several influencing factors on dye extraction efficiency were detailedly investigated and optimized with good performances. Both high purities of MIL and dye could be ideally recovered simply by heating and the recoveries of dyes were higher than 93%. Additionally, the two MILs could be recycled for at least 6 times with steadily high extraction efficiencies. Furthermore, this novel temperature-sensitive MILATPs had been successfully applied for real industrial dyed wastewater treatment with satisfactory recoveries of both MIL and dye. This novelly proposed temperature-sensitive MILATPs is simple and green method which is showing great potential in a separation-recovery process and the industrial treatment of dyed wastewater.

Magnetic-ionic-liquid-integrated microfiber Mach-Zehnder interferometer for simultaneous measurement of magnetic field and temperature

A microfiber Mach-Zehnder interferometer (MMZI) integrated with magnetic ionic liquid (MIL) for simultaneous measurement of magnetic field and temperature is proposed and experimentally demonstrated. The MMZI-based sensor is fabricated by splicing a section of microfiber between two segments of single- mode fibers with pre-designed lateral offset, and then encapsulating the sensor structure into a capillary tube filled with MIL. By monitoring the wavelength shifts of two interference dips in the transmission spectrum at the same time, magnetic field and environmental temperature can be simultaneously measured. Experimental results show that the magnetic field and temperature sensitivities reach 25.5 pm/Oe and −4.63 nm/°C for the magnetic field and temperature ranges of 0 Oe to 375 Oe and 30 °C to 42 °C, respectively. In order to resolve the temperature cross sensitivity, a sensor matrix is set up by employing different magnetic field as well as temperature sensitivities of the two selected transmission dips. Our proposed MMZI sensor has several desirable merits such as compact structure, ease of fabrication, and low cost, which make it a good candidate for magnetic field/temperature dual-parameter sensing and related applications.

Ultra-high stability and magnetic response of magnetorheological fluids based on magnetic ionic liquids and carbonyl iron fibers

A novel magnetic ionic liquid (IL) based on 1-methylethyl ether-3-butylimidazole cation and [FeCl4]− anion was synthesized for application as a carrier of magnetorheological fluids (MRFs). Stability and magnetic response of the MRFs were investigated as a function of the anion chemical structure and content of carbonyl iron fibers. The MRFs based on the magnetic ILs displayed better redispersibility, slower settling rates, and increased magnetic-induced stress compared with conventional MRFs based on oils or ILs. Furthermore, the mechanism of MRFs with good performance was investigated and proposed by molecular dynamic simulation. These results do not only confirm that the magnetic ILs are potential carriers of MRFs but also provide a new way to improve the stability and magnetic response of MRFs for various applications.

Simultaneous Measurement of Temperature and Magnetic Field Based on Ionic-Liquid-Infiltrated Side-Hole Fibers

A dual-parameter fiber-optic sensor based on magnetic ionic liquids (MILs) functionalized side-hole fibers (SHFs) has been proposed and experimentally demonstrated for simultaneous measurement of temperature and magnetic field intensity. Multiple transmission dips are present in the transmission spectrum due to resonance coupling between the fundamental core mode and high-order modes in the MIL inclusion. The wavelength shifts of these resonance dips are highly sensitive to the environmental temperature and applied magnetic field intensity, providing an ideal sensing platform for simultaneous measurement of the above two physical parameters. Experimental results indicate that our proposed sensor exhibits temperature and magnetic field sensitivities up to −3.466 nm/°C and −0.0303 nm/Oe for the measurement ranges of 25 °C to 100 °C and 20 Oe to 200 Oe, respectively. The MILs-infiltrated SHFs sensor paves new way toward developing photonic devices for temperature/magnetic field dual-parameter sensing and high-precision wavelength-tuning based on functional materials.

Literature review as a didactical content analysis: Sustainable magnetic lubricants based on ionic liquids

Magnetic lubricants are usually petroleum-based, but not renewable and cannot be environmentally degraded. It can cause the environmental problems. Magnetic lubricants based on ionic liquids can be environmental friendly. The ionic liquid lubricants are synthesized from vegetable oil fatty acids, which is a locally sustainable and renewable sources. This molecular engineering can be used to integrate the concept of sustainability into teaching and learning. This study aimed to obtain the concept map and teaching learning sequence (TLS) from the scientist’s conception. The method used is a qualitative content analysis (literature analysis type), using an instrument in the form of a content analysis format. The first phase begins with collecting literatures in the form of textbooks, monographs, review results and research articles. The next phase is descriptive analysis, selecting categories, and evaluating the material didactically. This research produces the concept map, TLS and clarified chemical concepts. The scientist’s conception obtained is the application, function, characteristics of media magnetic lubricants, ionic liquids and examples of magnetic lubricants based on ionic liquids. Concept map and TLS can illustrate the relationship between one concept and another. They also show the relationship between science, technology and engineering. The results can be used as the basis for the preparation of teaching materials and didactical designs for teaching and learning.

Guanidinium Hydrophobic Magnetic Ionic Liquid-Based Dispersive Droplet Extraction for the Selective Extraction of DNA.

Six hydrophobic magnetic guanidinium ionic liquids (HMILs) were designed and prepared for the extraction of DNA. The physical and thermal properties of the HMILs were characterized using vibrating sample magnetometry, density meter, rotational rheometer, Karl Fischer moisture, Fourier transform infrared spectrometry, and thermogravimetric analysis. Single-stranded DNA and duplex DNA extracted by HMILs can be rapidly collected by a magnet. Three assisted extraction methods, including vortex extraction, mechanical shaking extraction, and ultrasonic extraction, were introduced to extract DNA with HMILs and the extraction efficiencies were evaluated using NanoDrop. Influencing factors of the DNA extraction were comprehensively evaluated, involving the HMIL volume, extraction time, pH, and extraction temperature. The HMIL-based extraction method can well extract DNA from complex matrices and Escherichia coli cell lysates.

Magnetic Ionic Liquids in Sample Preparation: Recent Advances and Future Trends

In the last decades, a myriad of materials has been synthesized and utilized for the development of sample preparation procedures. The use of their magnetic analogues has gained significant attention and many procedures have been developed using magnetic materials. In this context, the benefits of a new class of magnetic ionic liquids (MILs), as non-conventional solvents, have been reaped in sample preparation procedures. MILs combine the advantageous properties of ionic liquids along with the magnetic properties, creating an unsurpassed combination. Owing to their unique nature and inherent benefits, the number of published reports on sample preparation with MILs is increasing. This fact, along with the many different types of extraction procedures that are developed, suggests that this is a promising field of research. Advances in the field are achieved both by developing new MILs with better properties (showing either stronger response to external magnetic fields or tunable extractive properties) and by developing and/or combining methods, resulting in advanced ones. In this advancing field of research, a good understanding of the existing literature is needed. This review aims to provide a literature update on the current trends of MILs in different modes of sample preparation, along with the current limitations and the prospects of the field. The use of MILs in dispersive liquid–liquid microextraction, single drop microextraction, matrix solid-phase dispersion, etc., is discussed herein among others.

Unravelling the Interactions of Magnetic Ionic Liquids by Energy Decomposition Schemes: Towards a Transferable Polarizable Force Field.

This work aims at unravelling the interactions in magnetic ionic liquids (MILs) by applying Symmetry-Adapted Perturbation Theory (SAPT) calculations, as well as based on those to set-up a polarisable force field model for these liquids. The targeted MILs comprise two different cations, namely: 1-butyl-3-methylimidazolium ([Bmim]+) and 1-ethyl-3-methylimidazolium ([Emim]+), along with several metal halides anions such as [FeCl4]−, [FeBr4]−, [ZnCl3]− and [SnCl4]2− To begin with, DFT geometry optimisations of such MILs were performed, which in turn revealed that the metallic anions prefer to stay close to the region of the carbon atom between the nitrogen atoms in the imidazolium fragment. Then, a SAPT study was carried out to find the optimal separation of the monomers and the different contributions for their interaction energy. It was found that the main contribution to the interaction energy is the electrostatic interaction component, followed by the dispersion one in most of the cases. The SAPT results were compared with those obtained by employing the local energy decomposition scheme based on the DLPNO-CCSD(T) method, the latter showing slightly lower values for the interaction energy as well as an increase of the distance between the minima centres of mass. Finally, the calculated SAPT interaction energies were found to correlate well with the melting points experimentally measured for these MILs.

Ultrasound-assisted dispersive solid phase extraction for promoting enrichment of ng L−1 level Hg2+ on ionic liquid coated magnetic materials

Herein, we investigated the enrichment behavior of inorganic mercury (Hg2+) on magnetic adsorbent with different ultrasound (US) energy field input. The enrichment rate of 0.10 μg L−1 mercury is increased by 4.5 times after US instead of stirring as dispersion mode. The input of higher frequency and power ultrasound can accelerate the enrichment of magnetic ionic liquid adsorbent and reduce the Hg2+ residue, importantly, which has not been reported. The positive correlation between cavitation effect and acoustic frequency and power in imaging experiments documents that US parameters are the key factors affecting the magnetic solid phase extraction. In addition, in-situ desorption and detection of adsorbate and recovery of adsorbent can be realized by slurry vapor generation (SVG) technology. The recovery of Hg2+ in four cycles is more than 90%, which indicates that the structure and properties of the material are not affected by the application of US. Hence, the degradation of adsorption properties caused by agglomeration of magnetic materials can be improved by introducing dispersion methods such as US. At the same time, 95% enrichment efficiency and 0.01–1.0 μg L−1 linear calibration range corresponding to 150 mL sample documents that magnetic ionic liquid adsorbent combined with US and sensitive spectral detector can meet the needs of ng L−1 level Hg2+ analysis in natural water samples.

Molecular dynamics simulation of extractive desulfurization of diesel oil model using magnetic ionic liquids

This paper serves as a molecular dynamics (MD) study on the desulfurization of diesel oil model using magnetic ionic liquids (MILs). In this regard, three different MILs, namely, [emim][FeCl4], [bmim][FeCl4] and [hmim][FeCl4] have been used to remove the dibenzothiophene (DBT) from n-dodecane as diesel oil model. The effects of alkyl chain length of cation in MIL, temperature, initial sulfur content and mass ratio of MIL to diesel oil on two vital parameters of desulfurization process i.e. percentage of S-removal and Nernst partition coefficient (KN) were investigated. These two parameters were calculated based on the method proposed by Feng and Mi (Ind. Eng. Chem. Res. 2014, 53, 20234-20240), in which they used the radial distribution function (RDF) plots obtained by Conductor-like Screening Model for Real Solvents (COSMO-RS) to evaluate the desulfurization of fuel oil, quantitatively. Our results showed that the [bmim][FeCl4] has the highest DBT-philisity and its S-removal efficiency increases with increasing temperature and the concentration of the MIL. Furthermore, from the investigation of the initial sulfur content in diesel oil model it is concluded that the MIL can be a good extractor for oil refinery applications with a wide range of sulfur content in diesel oil. The results of RDF and combined distribution function (CDF) plots and also Voronoi tessellation analysis showed that the DBT molecules are adsorbed mainly by the MIL molecules compared with the n-dodecane which leads to DBT-removal. Also, it is found that the DBT molecules interact with the cation of MIL more than its anion. The results of domain analysis showed that the n-dodecane subset is stiffer than the MIL and DBT subsets. Altogether, the Fe-containing MILs can be a good sulfur extractor with high S-removal efficiency, lower toxicity than common volatile organic solvents, and low cost compared to the other common methods such as hydrodesulfurization (HDS), for future oil refinery applications.

Magnetic ionic liquids as microRNA extraction solvents and additives for the exponential amplification reaction

The detection of microRNAs (miRNAs) from highly complex matrices has become an area of immense interest as their characterization in biological samples has been utilized for disease diagnosis and body fluid identification. However, conventional northern blotting miRNA detection lacks the sensitivity required to detect circulating miRNAs. Additionally, polymerase chain reaction-based methods for miRNA detection require modified oligonucleotides that are difficult to design. Exponential amplification reaction (EXPAR) is an isothermal amplification method used for miRNA detection that is simple to design but suffers from non-specific amplification that masks low concentration miRNAs. Previous studies have shown that magnetic ionic liquids (MILs) are a promising alternative to traditional nucleic acid extraction methods capable of preconcentrating DNA from complex matrices. In this study, three hydrophobic magnetic ionic liquids (MILs) were investigated as EXPAR additives and miRNA extraction solvents. The addition of MIL to the EXPAR buffer decreased the background signal from non-specific amplification and increased the reaction rate. Reactions containing MIL could detect miRNA at concentration levels down to 10 aM. In comparison, reactions that did not contain MIL could not discriminate 10 fM lethal-7a (let-7a) standards from the no trigger control (NTC). All three MILs extracted miRNA from 2-fold diluted plasma, artificial urine, and artificial saliva with only a 1 min dispersion step. By integrating the miRNA-enriched MIL into the EXPAR buffer, the extraction and detection of femtomolar concentrations of miRNA required only 10 min. In contrast, conventional spin column kits require at least 20 min to isolate miRNA, indicating that a dispersive MIL-based extraction is ideal for high throughput analysis of miRNA.

Determination and correlation of phase equilibria of chiral magnetic ionic liquid aqueous two-phase systems with different inorganic salts at 298.15 K

Three novel chiral magnetic ionic liquids (MILs) with L-Pro anion were synthesized and applied to construct chiral magnetic ionic liquid aqueous two-phase systems (chiral MILATPs). This is the first reported chiral MILATPs and is showing great potential in the extractive resolution of racemic amino acids. In this work, aqueous two phase equilibrium binodal data of these chiral MILATPs ([CnMIM-Tempo][L-Pro](n = 2–4) + K2CO3/K3PO4/Na2CO3/Na2SO4 + H2O) were measured at temperature of 298.15 K. Three classical empirical equations including Merchuk equation were applied for the correlation of the experimental binodal data to obtain the binodal curve. Satisfactory correlation performances were achieved. The screening of inorganic salt revealed that K2CO3 and K3PO4 are better salting-out reagents than Na2CO3 and Na2SO4. Investigation of chiral MIL species demonstrated that chiral MIL with longer alkyl chain length of cation has better phase forming ability when the values of n are in the ranges of 2–4. Moreover, tie-line data for systems containing K2CO3 or K3PO4 were measured and correlated by Othmer-Tobias equation with satisfactory fitting performances (all R2 higher than 0.99). These results has ensured the reliability of these experimental data. The phase behaviors of these chiral MILATPs in this work has proved to meet the need of practical application and all these tested aqueous two-phase equilibrium data as well as the corresponding thermodynamic fitting can provide us useful reference for the future application in the field of extractive resolution of racemic amino acids.

Recyclable Magnetic Fe3O4 Nanoparticle-Supported Chloroaluminate Ionic Liquids for Heterogeneous Lewis Acid Catalysis

Recyclable Magnetic Fe₃O₄ Nanoparticle-Supported Chloroaluminate Ionic Liquids for Heterogeneous Lewis Acid Catalysis

Spin glass behavior and magnetic boson peak in a structural glass of a magnetic ionic liquid

Glassy magnetic behavior has been observed in a wide range of crystalline magnetic materials called spin glass. Here, we report spin glass behavior in a structural glass of a magnetic ionic liquid, C4mimFeCl4. Magnetization measurements demonstrate that an antiferromagnetic ordering occurs at TN = 2.3 K in the crystalline state, while a spin glass transition occurs at TSG = 0.4 K in the structural glass state. In addition, localized magnetic excitations were found in the spin glass state by inelastic neutron scattering, in contrast to spin-wave excitations in the ordered phase of the crystalline sample. The localized excitation was scaled by the Bose population factor below TSG and gradually disappeared above TSG. This feature is highly reminiscent of boson peaks commonly observed in structural glasses. We suggest the “magnetic” boson peak to be one of the inherent dynamics of a spin glass state.

Extractive resolution of racemic phenylalanine and preparation of optically pure product by chiral magnetic ionic liquid aqueous two-phase system

In this report, chiral magnetic ionic liquid aqueous two-phase system was developed for the first time. Three novel chiral magnetic ionic liquids ([C2-4MIM-Tempo][L-Pro]) were synthesized and successfully used to construct aqueous two-phase system with inorganic salts (K2HPO4, K2CO3, K3PO4, Na2SO4, Na2CO3) for the extractive resolution of racemic phenylalanine. This novel system combined the advantages of organic solvent free, magnetic phase separation and rapid extraction together in an enantiomer resolution process for the first time. Phase behaviors and various influencing factors on resolution performance were systematically studied and optimized. The optimal extractive resolution conditions are: 1.4 g added water, 450 mg [C4MIM-Tempo][L-Pro], 100 mg Cu(OAc)2, 20 mg DL-Phe, 0.85 g K2HPO4, pH of added water as 7, system temperature as 298.15 K. Based on this, a novel preparation method of highly optically pure L-phenylalanine and D-phenylalanine was developed and achieved a satisfactory performance even in gram-scale. The e.e. value of L-phenylalanine in chiral MIL-rich phase reached 94.3% and the e.e. value of D-phenylalanine in salt-rich phase could reach 98.1%. Moreover, chiral magnetic ionic liquid could be recycled for at least 6 times with consistently good resolution ability. Hopefully, this green and recyclable resolution approach is showing great potential in industry.

Determination of four parabens in cosmetics by high-performance liquid chromatography with magnetic solid-phase and ionic dispersive liquid–liquid extraction

Abstract To determine the trace amount of four benzoic acid esters in cosmetics, ionic dispersive liquid–liquid microextraction (DLLME) and magnetic solid-phase extraction were combined and optimized. After solvent optimization, 1-octyl-3-methylimidazolium hexafluorophosphate was selected as the extraction solvent to form hydrophobic droplets in the process of ionic DLLME, followed by removal of ions from the sample solution containing Fe3O4@GO nano-materials. The magnetic nano-materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. Some parameters affecting the efficiency of extraction were optimized using Box-Behnken design. Under optimized conditions, the limit of detection for all the preservatives was less than 0.135 mg/L and the accuracy ranged from 88.5% to 101%. This technology could determine the trace amount of preservatives in cosmetics with comparatively higher accuracy and sensitivity.