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The present study focused on coupling cellulose nanofibers (alternative materials for plastics and metals) with a magnetic ionic liquid (synthesized by a microwave-assisted method) through mixing to yield magnetic cellulose nanofibers (MCNFs) that can be recycled by attracting them to a magnet. Accordingly, two types of ionic liquids were synthesized: (a) 1-butyl-3-methylimidazolium tetrachloroferrate(III) {[bmim] FeCl 4 } and (b) 1-glycidyl-3-methylimidazolium tetrachloroferrate {[glmi]FeCl 4 }, which were characterized by the fast atom bombardment mass spectrometry (FAB-MS) technique. Impregnation of the cellulose nanofibers with the {[bmim]FeCl 4 } ionic liquid caused the latter to be physically adsorbed onto the nanofibers to produce {MCNF@{[bmim]FeCl 4 }, whereas the corresponding {[glmi]FeCl 4 } ionic liquid was chemically bonded to the cellulose nanofibers to yield magnetic {MCNF@[glmi]FeCl 4 } nanofibers. Under the experimental conditions used, the corresponding magnetic moments were 0.222 A m 2 kg -1 for {MCNF@ {[bmim]FeCl 4 } and 0.095 A m 2 kg -1 for {MCNF@[glmi]FeCl 4 }.

Plants contain many kinds of natural organic compounds, and their compounds possess many useful properties. Natural organic compounds are important for the development of medicines, pesticides, fragrances, cosmetics, and synthetic chemicals. In this chapter, we introduce efficient methods for extraction and isolation of valuable natural organic compounds from various plant leaves by using cellulose-dissolving ionic liquids. High-polarity ionic liquids, which can dissolve cellulose, contribute to the extraction of natural organic compounds from plant leaves probably by breaking down plant cell walls, which are composed of cellulose, hemicellulose, and lignin. Extraction and isolation of shikimic acid from ginkgo leaves, caffeoylquinic acids from sweet potato leaves, and neral and geranial (which combine to form citral) from lemon myrtle leaves were performed. Ionic liquids can achieve extraction rates greater than those achieved with water and other organic solvents. Graphical Abstract.

Shikimic acid, the starting material in the commercial synthesis of oseltamivir phosphate (Tamiflu®), was efficiently extracted and isolated from Ginkgo biloba leaves utilizing the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl), which dissolves cellulose., (This journal is © The Royal Society of Chemistry 2011)

Cations in ionic liquids (ILs) are typically derived from ammonium or phosphonium structures with long alkyl chains, and it is well established that the central atom significantly influences the properties of the resulting ILs. In this study, an arsonium-based IL, trihexylmethylarsonium bis(trifluoromethylsulfonyl)amide, was synthesized. The arsonium cation was found to contribute to lower viscosity and higher ionic conductivity, while maintaining sufficient stability compared to its phosphonium counterpart. [ABSTRACT FROM AUTHOR]

A zwitterion is a neutral compound that has both a cation and an anion in the same molecule. Quaternary ammonium cations are frequently used for zwitterions. Zwitterions with quaternary ammonium cations are also common in biological molecules, such as phospholipids, which are the main components of cell membranes. Chemically, they have broad applicability because they are dielectric, non‐volatile, and highly polar compounds with a large dipole moment. In addition, after salt addition, ion exchange does not occur in the presence of zwitterions. Owing to these characteristics, zwitterions have been applied as novel electrolyte materials targeting high ionic conductivity. In this review, application of zwitterions and their polymers for Li‐ion batteries is addressed. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA) is a resin derived from biomass. In addition to its various superior properties, CA is preferable to existing petroleum-derived resins from the viewpoint of green chemistry. Therefore, the acetylation of cellulose is one of the most important subjects in cellulose research. In this study, we found that the acetylation of cellulose could proceed in some protic ionic liquids (PILs) composed of amidine and acetic acid with ΔpKa = ca. 8.4–8.7 under mild conditions without any catalyst. The degree of substitution (DS) of the produced CA was above 1.84, and the maximum DS was 2.87 when the ΔpKa of the PIL was about 8.5. In propionate-based PILs, cellulose was not only acetylated but also propionated; however, the cellulose acetylation did not occur in formate-based PILs. It was revealed that the esterification of cellulose proceeded through the anion exchange between carboxylic anhydride and anion species of the PIL. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) containing zwitterions have been studied as electrolytes for lithium-ion batteries (LIBs). The effects of addition of a pyrrolidinium zwitterion in an IL electrolyte on the thermal and electrochemical stability and charge/discharge properties of Li/LiCoO 2 and graphite/Li cells were investigated. The thermal decomposition temperature of the IL electrolyte composed of N -methyl- N -propylpyrrolidinium bis(fluorosulfonyl)amide ([P13][FSA])/lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) with 3-(1-butylpyrrolidinium)propane-1-sulfonate (Bpyps) as the zwitterionic additive, the thermal decomposition temperature was about 300 °C. The electrochemical window of [P13][FSA]/LiTFSA/Bpyps was 0–+5.4 V vs. Li/Li + , which was almost identical to that of [P13][FSA]/LiTFSA. Li|electrolyte|LiCoO 2 cells containing the IL/Bpyps electrolyte system exhibited high capacities in the cut-off voltage range of 3.0–4.6 V, even after 50 cycles. The increase in the interfacial resistance between the electrolyte and cathode with cycling was suppressed. In the cyclic voltammograms of cells employing a graphite electrode, the intercalation/deintercalation of lithium ions were observed in the range of 0 and + 0.4 V vs. Li/Li + . Further, graphite|electrolyte|Li cells containing [P13][FSA]/LiTFSA/Bpyps exhibited stable charge/discharge cycle behaviour over 50 cycles. [ABSTRACT FROM AUTHOR]

Lipase-catalyzed polymerizations of L-lactide were carried out in four kinds of ionic liquids (ILs) in order to investigate the effect of ILs on the conversion, molecular weight, and yield of the obtained poly(lactide) (PLLA). PLLA could be synthesized in ILs of 1-butyl-3-methylimidazolium ([C4mim]) except in [C4mim][N(CN)2]. While the number-average molecular weight ( Mn) of the PLLA obtained in [C4mim][PF6] was below 4000 g mol−1 and the yield was below 10%, the Mn and yield of the PLLA obtained in [C4mim][BF4] reached 55000 g mol−1 and 35%, respectively. The Mn values of PLLAs in the ILs were clearly higher than those of PLLAs obtained in bulk and in toluene (<44000 g mol−1). The polymerization in the ILs proceeds even at lower temperatures as compared with that in bulk. The effect of lipase content on the Mn of PLLA was also investigated. When [C4mim][BF4] was used as the solvent, the highest Mn was obtained at a lipase content of 10 wt%. In the case of [C4mim][NTf2], the most suitable lipase content depended on the polymerization temperature. [C4mim][BF4] was suitable to obtain higher molecular weight PLLA and higher polymer yield at lower lipase contents. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: We have synthesized two kinds of new Lewis-base ionic liquids (ILs); one is based on the relatively strong Lewis basic acetate anion, and the other is a salt composed of a mono-alkylated diamine such that the Lewis base site is incorporated in the cation. 1-Octyl-4-aza-1-azonia-bicyclo[2.2.2]octane bis(trifluoromethanesulfonyl)amide, [C8dabco]TFSA, and N-butyl-N-methylpyrrolidinium acetate, [p1,4]OAc, melted into fluid liquids at 26 and 81°C, respectively. The thermal decomposition of [p1,4]OAc started at around 150°C, whereas the thermal stability of [C8dabco]TFSA was almost equal to that of typical TFSA-based ILs in spite of the Lewis base site. This suggests that if the Lewis base site is incorporated into the cation the IL can maintain higher thermal stability. In addition, as a further result of the presence of the basic nitrogen, [C8dabco]TFSA can dissolve hydrated Cu(NO3)2 whereas the other TFSA-based ILs cannot. [Copyright &y& Elsevier]

After decades of development, ionic liquid gel polymer electrolytes (ILGPEs) are currently experiencing a renaissance as a promising electrolyte to be used in electrochemical devices. Their inherent tendency towards poor electrochemical properties have limited their applications and commercialization activities. Henceforth, gel polymer electrolyte (GPE) is being introduced to alleviate the abovementioned issues. In this work, the assessment of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] in poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) to form ILGPE was done. The relationship of [BMIM][BF4] towards the dielectric properties at different wt. % ratios and temperature was ascertained. The results indicated that [BMIM]BF4 is able to facilitate fast conduction. Moreover, it was found that [BMIM][BF4] could serve as an effective agent in reducing crystallinity and glass transition temperature of the polymer and thus enhanced the ionic conductivity of the samples. Notwithstanding, the ILGPE sample possessed a high thermal stability up to 300 °C and good electrochemical stability of 4.2 V which are beneficial for operation in electrochemical devices. All in all, the correlation between the ionic liquid chemistry and electrochemical performances could provide a valuable insight to rational selection and design for ILGPE electrolytes. [ABSTRACT FROM AUTHOR]

Abstract: Lithium was electrochemically inserted from a Li+ ion containing ionic liquid into graphite or tin to observe lithium isotope effects that accompanied the insertion. While no preferential uptake of the lithium isotopes was detected with graphite, the lighter isotope, 6Li, was preferentially fractionated into tin with the single-stage lithium isotope separation factors, S, ranging from 1.004 to 1.008 at 25 °C. It was speculated that a Li+ ion was inserted into graphite together with an anionic component of the ionic liquid and, upon the reduction of the Li+ ion to a lithium atom, the anion was released from graphite, while a Li+ ion alone was inserted into tin. Molecular orbital calculations supported this speculation in a qualitative fashion. [Copyright &y& Elsevier]

A protic ionic liquid (PIL) composed of 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) and acetic acid can dissolve cellulose under mild conditions and catalyse its transesterification. To investigate the relationship between physicochemical properties and chemical structures, PILs composed of DBU and carboxylic acids with varying alkyl chain lengths were prepared as cellulose-dissolving solvents. The thermal behaviours of the PILs were analysed by thermogravimetry and differential scanning calorimetry, and their viscosities, ionic conductivities, and cellulose-dissolution abilities were determined. The effect of the alkyl chain length in the carboxylate ion on the physicochemical properties of the PILs was investigated. With increasing chain length, the thermal stability and ionic conductivity increased, whereas the melting point (T m), glass-transition temperature (T g), cellulose solubility, and viscosity decreased. The cellulose solubility increased as the difference between the p K a values of the DBU and carboxylic acid (Δp K a) increased. In addition, the cellulose solubility increased with the increasing density of the PIL. It was revealed that PILs with a high Δp K a value and a carboxylate ion with a short alkyl chain are suitable for cellulose dissolution. A protic ionic liquid (PIL) composed of 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) and acetic acid can dissolve cellulose under mild conditions and catalyse its transesterification. In this study, PILs composed of DBU and carboxylic acids with varying alkyl chain lengths were prepared, and the relationship between physicochemical properties and chemical structures was investigated. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) containing zwitterions were studied as electrolytes for lithium-ion batteries. The effect of a pyrrolidinium zwitterion with a long ether side chain on the thermal and electrochemical properties of an IL and the charge/discharge properties of Li/LiCoO 2 , Li/LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC), and graphite/Li cells with IL/zwitterion electrolytes was investigated. The melting temperature of the IL-based electrolyte composed of N -methyl- N -methoxymethylpyrrolidinium bis(fluorosulfonyl)amide ([Pyr 1,1O1 ][FSA]) and lithium bis(fluorosulfonyl)amide (LiFSA) with 3-(1-(2-(2-methoxyethoxy)ethyl)pyrrolidin-1-ium-1-yl)propane-1-sulfonate (OE2pyps) as the zwitterionic additive was about −18 °C. The electrochemical window of [Pyr 1,1O1 ][FSA]/LiFSA/OE2pyps was over 5 V vs. Li/Li + . Li|electrolyte|LiCoO 2 cells containing the [Pyr 1,1O1 ][FSA]/LiFSA/OE2pyps electrolyte system exhibited high capacity values in the cut-off voltage range of 3.0–4.3 V, even after 50 cycles. Moreover, increases of interfacial resistance between the electrolyte and cathode during cycling were suppressed. Li|electrolyte|NMC cells containing this electrolyte system also exhibited high capacities in a wide cut-off voltage range of 3.0–4.6 V, even after 50 cycles. In the cyclic voltammograms of cells employing a graphite electrode, the intercalation/deintercalation of lithium ions was observed between 0 and + 0.4 V vs. Li/Li + . Further, graphite|electrolyte|Li cells containing [Pyr 1,1O1 ][FSA]/LiFSA/OE2pyps exhibited stable charge/discharge cycle behavior over 5 cycles. [ABSTRACT FROM AUTHOR]