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Concept: 1-Butyl-3-methylimidazolium hexafluorophosphate


Abundant lignocellulosic biomass could become a source of sugars and lignin, potential feedstocks for the now emergent bio-renewable economy. The production and conversion of sugars from biomass have been well-studied, but far less is known about the production of lignin that is amenable to valorization. Here we report the isolation of lignin generated from the hydrolysis of biomass dissolved in the ionic liquid 1-butyl-3-methylimidazolium chloride. We show that lignin can be isolated from the hydrolysate slurry by simple filtration or centrifugation, and that the ionic liquid can be recovered quantitatively by a straightforward wash with water. The isolated lignin is not only free from ionic liquid, but also lacks cellulosic residues and is substantially depolymerized, making it a promising feedstock for valorization by conversion into fuels and chemicals.

Concepts: Scientific method, Water, Ionic liquid, Cellulose, Maize, Social sciences, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


In the present study, a rapid and repeatable microemulsion electrokinetic chromatography (MEEKC) method was developed for the simultaneous determination of three isomers (α-, β- and γ-asarone) in Acorus tatarinowii by using ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF(6)) as oil phase. Experimental parameters including the microemulsion compositions (concentrations of surfactant, co-surfactant and oil phase), pH, concentration of borate buffer, capillary temperature and voltage were intensively investigated. Finally, the main compounds in the methanol extract of A. tatarinowii were well separated within 11min using a running buffer composed of 40mmol/L sodium dodecyl sulfonate (SDS), 2.0mol/L n-propanol, 8mmol/L [BMIM]PF(6) in 10mmol/L borate buffer of pH 9.5. The developed method was applied to determine the contents of α-, β- and γ-asarone in A. tatarinowii from five different producing areas in China (Anhui, Hebei, Sichuan, Zhejiang and Chongqing). The results indicated that the contents of three asarones are quite different in the investigated A. tatarinowii samples. On the other hand, the MEEKC with ionic liquid as oil phase should be a promising method for the analysis of volatile components especially isomers in medicinal herbs.

Concepts: Liquid, Yangtze River, Emulsion, Ionic liquid, Borax, 1-Butyl-3-methylimidazolium hexafluorophosphate, Hexafluorophosphate, Ionic liquids


In this manuscript, we have characterized two different micellar aggregates containing all nonvolatile components. We have shown (i) the effect of ethylammonium nitrate (EAN) addition on the properties of micellar solution of Triton X-100 in 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF(6)) and (ii) the effect of bmimPF(6) addition on the properties of micellar solution of Triton X-100 in EAN. To investigate the effect, we have used (1)H NMR, pulsed-field gradient spin-echo NMR (PFGSE NMR), and methyl orange (MO) and coumarin 153 (C-153) as absorption and emission probes, respectively. The penetration of added EAN inside the Triton X-100/bmimPF(6) micellar aggregates is indicated by (i) red shift in both the absorption spectra of MO and emission spectra of C-153 and (ii) downfield shift of proton signals of ethylene oxide units in Triton X-100. On the other hand, (1)H NMR and PFGSE NMR indicates the penetration of added bmimPF(6) inside the Triton X-100/EAN micellar aggregates. However, the constancy of both the absorption spectra of MO and emission spectra of C-153 indicates that the microenvironment around the probe molecules remains unaffected. We have also investigated the effect of micelle formation and the effect of penetration of ionic liquids (ILs) in micellar aggregates, on the solvation dynamics of C-153. The solvent relaxation around C-153 gets retarded on going from neat ILs to the micellar solution of Triton X-100 in ILs. In addition to this, we have also observed that with the addition of EAN in Triton X-100/bmimPF(6) micellar aggregates the solvation dynamics becomes faster, whereas with the addition of bmimPF(6) in Triton X-100/EAN micellar aggregates we did not observe any notable change in solvation dynamics. This observation further supports the conclusions drawn from UV-visible and NMR studies.

Concepts: Solvent, Ionic liquid, Absorption spectroscopy, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ethylammonium nitrate, Hexafluorophosphate, Ionic liquids, Paul Walden


BACKGROUND: In the present study, three ionic liquids, namely 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), and 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM]DEP), were used to partially dissolve rice husk, after which the cellulose were regenerated by the addition of water. The aim of the investigation is to examine the implications of the ionic liquid pretreatments on rice husk composition and structure. RESULTS: From the attenuated total reflectance Fourier transform-infrared (ATR FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results, the regenerated cellulose were more amorphous, less crystalline, and possessed higher structural disruption compared with untreated rice husk. The major component of regenerated cellulose from [BMIM]Cl and [EMIM]DEP pretreatments was cellulose-rich material, while cellulose regenerated from [EMIM]OAc was a matrix of cellulose and lignin. Cellulose regenerated from ionic pretreatments could be saccharified via enzymatic hydrolysis, and resulted in relatively high reducing sugars yields, whereas enzymatic hydrolysis of untreated rice husk did not yield reducing sugars. Rice husk residues generated from the ionic liquid pretreatments had similar chemical composition and amorphousity to that of untreated rice husk, but with varying extent of surface disruption and swelling. CONCLUSIONS: The structural architecture of the regenerated cellulose and rice husk residues showed that they could be used for subsequent fermentation or derivation of cellulosic compounds. Therefore, ionic liquid pretreatment is an alternative in the pretreatment of lignocellulosic biomass in addition to the conventional chemical pretreatments.

Concepts: Starch, Scientific techniques, Ionic liquid, Cellulose, Scanning electron microscope, Cellulosic ethanol, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


Complete biodegradation of a newly-synthesized chemical in a wastewater treatment plant (WWTP) eliminates the potential for novel environmental pollutants. However, differences within- and between-WWTP microbial communities may alter expectations for biodegradation. WWTP communities can also serve as a source of unique consortia that, when enriched, can metabolize chemicals that tend to resist degradation, but are otherwise promising green alternatives. We tested the biodegradability of three ionic liquids (ILs): 1-octyl-3-methylpyridinium bromide (OMP), 1-butyl-3-methylpyridinium bromide (BMP) and 1-butyl-3-methylimidazolium chloride (BMIM). We performed tests using communities from two WWTPs at three time points. Site-specific and temporal variation both influenced community composition, which impacted the success of OMP biodegradability. Neither BMP nor BMIM degraded in any test, suggesting that these ILs are unlikely to be removed by traditional treatment. Following standard biodegradation assays, we enriched for three consortia that were capable of quickly degrading OMP, BMP and BMIM. Our results indicate WWTPs are not functionally redundant with regard to biodegradation of specific ionic liquids. However, consortia can be enriched to degrade chemicals that fail biodegradability assays. This information can be used to prepare pre-treatment procedures and prevent environmental release of novel pollutants.

Concepts: Water, Sewage treatment, Ionic liquid, Soil contamination, Land degradation, Green chemistry, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


Agarose has been functionalized (acetylated/carbanilated) in an ionic liquid (IL) medium of 1-butyl-3-methylimidazolium acetate at ambient conditions. The acetylated agarose showed a highly hydrophobic nature, whereas the carbanilated agarose could be dissolved in water as well as in the IL medium. Thermoreversible ionogels were obtained by cooling the IL sols of carbanilated agarose at room temperature. The ionogel prepared from a protic-aprotic mixed-IL system (1-butyl-3-methylimidazolium chloride and N-(2-hydroxyethyl)ammonium formate) demonstrated a superior self-healing property, as confirmed from rheological measurements. The superior self-healing property of such an ionogel has been attributed to the unique inter-intra hydrogen-bonding network of functional groups inserted in the agarose. The ionogel was tested as a flexible solid electrolyte for an activated-carbon-based supercapacitor cell. The measured specific capacitance was found to be comparable with that of a liquid electrolyte system at room temperature and was maintained for up to 1000 charge-discharge cycles. Such novel functionalized-biopolymer self-healing ionogels with flexibility and good conductivity are desirable for energy-storage devices and electronic skins with superior lifespans and robustness.

Concepts: Water, Electrochemistry, Solid, Liquid, Ionic liquid, Gas, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


A series of hybrid tellurium chlorides based on ionic liquids (ILs), namely, α-[Bmim]2TeCl6 (1, Bmim = 1-butyl-3-methyl imidazolium), β-[Bmim]2TeCl6 (2), [HOOCMim]2TeCl6 (3, HOOCMim = 1-carboxymethyl-3-methyl imidazolium), [Bzmim]2TeCl6 (4, Bzmim = 1-benzyl-3-methyl imidazolium), [EPy]2TeCl6 (5, EPy = 1-ethylpyridinium), [Bmmim]2TeCl6 (6, Bmmim = 1-butyl-2,3-dimethyl imidazolium), have been synthesized and characterized. Different kinds of supramolecular networks have been obtained via self-assemblies of isolated [TeCl6]2- anions and various ionic liquid cations. Interestingly, all the title compounds exhibit semiconducting behaviors: their optical absorption edges calculated from reflectance spectra are in the range of 2.54-2.68 eV; their electrical conductivities measured by using two-probe direct current (DC) method indicate values from 2.06 × 10-9 to 4.65 × 10-6 S/cm, which are typical for semiconductors and comparable to the reported crystalline hybrid metal halides. The luminescent property studies reveal that only compounds 3 and 6 exhibit intense emissions both at 77 and 298 K, probably owing to the minimum distortion of the TeCl6 octahedra in 3 and 6.

Concepts: Ion, Semiconductor, Ionic liquid, Electrical conductivity, Ions, Green chemistry, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


Zinc oxide nanoparticles of 60 nm were dispersed in PBS and 2 different ionic liquids- choline acetate, 1-Butyl-3-methylimidazolium chloride. These formulations were tested in 4 different strains- Escherichia coli, Bacillus cereus, Klebsiella pneumoniae, and Staphylococcus epidermidis. Out of these combinations, maximum efficiency was obtained for ZnO nanoparticle dispersed in imidazolium based ionic liquid against skin specific S. epidermidis. Through a series of experiments, it has been established that the mechanism of killing this skin-specific bacteria is through ROS production leading to bacterial cell lysis. Further, it was also established that this formulation is biocompatible and non-toxic to normal keratinocyte cells under co-culture conditions.

Concepts: Bacteria, Staphylococcus, Escherichia coli, Enterobacteriaceae, Ionic liquid, Staphylococcus epidermidis, 1-Butyl-3-methylimidazolium hexafluorophosphate, Ionic liquids


Lignocellulose is considered a major source for the production of valuable chemicals. Efficient degradation of lignin as the natural carrier of the lignocellulosic biomass represents a key limiting factor in biomass digestibility. Recently, biological delignification methods have been promoted as sustainable and environmentally friendly alternatives to the traditional technologies. In this study, porous nanocomposite of Fe3O4@SiO2@KIT-6 with magnetic properties was synthesized. The immobilized laccase supported on nanocomposite with enhanced stability in a hydrophobic ionic liquid has been developed for both olive pomace delignification and degradation of phenolic extracts from the pomace. After 6 h incubation, the degradation rate of lignin and phenol by the immobilized laccase was estimated to be 77.3% and 76.5%, respectively. The immobilized laccase retained 70% of its initial degradation ability after 11 successive batch treatments of olive pomace. Furthermore, the immobilized laccase retained >70% of its initial activity after 21 days of storage at room temperature. The obtained results indicated that the immobilized laccase on magnetic mesoporous support together with (1-Butyl-3-methylimidazolium hexafluorophosphate) ([Bmim][PF6]) could potentially provide a promising procedure for an improved enzymatic degradation of lignin and phenol in the related industries.

Concepts: Magnetism, Ionic liquid, Immobilized enzyme, Vanillin, 1-Butyl-3-methylimidazolium hexafluorophosphate, Hexafluorophosphate, Ionic liquids, Ligninase


Sulfonamides are antibiotics widely used in the treatment of diseases in dairy cattle. However, their indiscriminate use for disease control may lead to their presence in tissues and milk and their determination requires a sample preparation step as part of an analytical approach. Among the several sample preparation techniques available, those based upon the use of sorptive materials have been widely employed. Recently, the application of ionic liquids immobilized on silica surfaces or polymeric materials has been evaluated for such an application. This manuscript addresses the evaluation of silica based ionic liquid obtained by a sol-gel synthesis process by basic catalysis as sorbent for on-line solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry for sulfonamides determination. Infrared vibrational spectroscopy confirmed the presence of the ionic liquid on the silica surface, suggesting that the ionic liquid was anchored on to the silica surface. Other sorbents varying the ionic liquid alkyl chain were also synthesized and evaluated by off-line solid-phase extraction in the sulfonamide extraction. As the length of the alkyl chain increased, the amount of extracted sulfonamides decreased, possibility due to a decrease in the electrostatic interaction caused by the reduction in the polarity, as well as the presence of a hexafluorophosphate anion that increases the hydrophobic character of the material. The use of 1-butyl-3-methylimidazolium hexafluorophosphate as a selective ionic liquid sorbent enabled the isolation and sulfonamide pre-concentration in bovine milk by on-line solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The limit of quantification for the method developed was 5-7, 5 μg/mL < ? > < ? > Author: please check values < ? > < ? > , with extraction recoveries ranging between 74 and 93% and intra- and inter-assay, between 1.5-12.5 and 2.3-13.1, respectively. This article is protected by copyright. All rights reserved.

Concepts: Spectroscopy, Mass spectrometry, Analytical chemistry, Cattle, Ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate, Hexafluorophosphate, Ionic liquids