Electrodeposition of nanocrystalline silver films and nanowires from the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate

We report in this paper on the electrodeposition of nanocrystalline silver films and nanowires in the air and water stable ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate [EMIm]TfO containing Ag(TfO) as a source of silver. The study was performed by means of cyclic voltammetry and chronoamperometry, and the electrodeposits were characterized by SEM-EDX and XRD. The cyclic voltammetry behaviour showed typical reduction and oxidation peaks corresponding to the deposition and stripping of silver in the employed electrolyte. XRD patterns of the electrodeposited silver layers revealed the characteristic peaks of crystalline silver with crystallites in the nanosize regime. Silver nanowires with average diameters and lengths of about 200 nm and 3 μm, respectively, were prepared by potentiostatic deposition within a commercial nuclear track-etched polycarbonate template.     

基于COSMO-RS模型的分离油酚混合物的离子液体萃取剂筛选

低温煤焦油中酚类化合物的分离对其充分利用具有重要意义。基于COSMO-RS模型,以间甲酚和异丙苯作为模型化合物,研究了离子液体在分离油酚体系中的应用;利用Turbomole软件建立了包含27种离子液体阴离子和48种离子液体阳离子的s-图谱数据库,结合COSMOtherm软件对组成的1296种离子液体进行筛选,探讨了阴阳离子对间甲酚分离效果的影响,并对筛选得到适宜的离子液体进行液液相平衡实验验证。结果表明,离子液体阴离子对间甲酚分离效果影响较大,以Cl^-和CH₃COO^-为阴离子的离子液体与间甲酚之间具有较强的氢键相互作用,因此具有较好的分离效果;阳离子对间甲酚分离效果影响较小,碳链或支链的增加能适当提高离子液体对间甲酚的分离效果。实验得到的bmimOAc、bmimCl、emimOAc、TPAC四种离子液体-间甲酚-异丙苯的液液相平衡数据表明,四种离子液体对间甲酚均具有较大的分配系数和选择性,且萃取分离效果的顺序为：emimOAc > bmimOAc > TPAC > bmimCl,与COSMO-RS模拟筛选得到的结果一致,表明筛选具有较高的准确性。     

Effect of water on extractive desulfurization of fuel oils using ionic liquids:A COSMO-RS and experimental study

When evaluating ionic liquids(ILs) for extractive desulfurization(EDS) of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work,COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H_2 O mixtures,which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C_4MIM][H_2PO_4], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the crosssolubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range(b 10 wt%) was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent–solute interactions and the COSMO-RS based analysis.     

A study on designing a paired electrolysis for electro-induced Michael addition using tetrafluoroborate-based ionic liquid as electrolysis medium and pre-catalyst in a divided cell

Simultaneous double electro-induced synthesis of Michael adducts in both the compartments of a divided cell has been achieved by galvanostatic electrolysis in 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid, exploiting the direct electro-generation of the enolate in the cathodic side and the electro-generation of the Lewis acid BF₃ in the anodic side of the cell.     

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate: Preparation, physico-chemical characterization, and theoretical study

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether (PEGdME) and the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF₆) have been prepared and characterized by different techniques. Coordination of the IL by the polymer occurs mainly in the amorphous phase. This finding was correlated with previous theoretical investigations of a similar model for polymer electrolytes based on poly(ethylene oxide), PEO, and IL. It has been obtained ionic conductivity σ ∼ 10⁻³ S cm⁻¹ for the polymer electrolyte with 35 wt% of IL at 100 °C. The same order of magnitude for σ was obtained by molecular dynamics simulation of PEO/IL. This work demonstrates consistency between experimental and theoretical results for polymer electrolytes containing ionic liquids.     

Physicochemical properties of glycine-based ionic liquid [QuatGly-OEt][EtOSO(3)] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate) and its binary mixtures with poly(ethylene glycol) (M(w) = 200) at various temperatures

This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL) [QuatGly-OEt][EtOSO(3)] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO(3)] with poly(ethylene glycol) (PEG) [M(w) = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO(3)] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF) equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (V(m) (E) ) and deviations (Δη, Δ(x)n, Δ(Ψ)n, Δ(x)R, and Δ(Ψ)R) are discussed in terms of molecular interactions and molecular structures in the binary mixture.     

High-pressure phase equilibria for the synthesis of ionic liquids in compressed CO2 for 1-hexyl-3-methylimidazolium bromide with 1-bromohexane and 1-methylimidazole

The use of carbon dioxide in the synthesis of ionic liquids (ILs) has many advantages over conventional solvents. Here, the high-pressure phase equilibria (including CO₂ solubility, volume expansion, and mixture critical points) are measured and modeled for the system involved in the synthesis of a model imidazolium ionic liquid 1-hexyl-3-methylimidazolium bromide ([HMIm][Br]) from 1-bromohexane and 1-methylimidazole. The global phase behavior of 1-methylimidazole was investigated and found to be a Type V system (or potentially IV) from the classification of Scott and van Konynenburg with regions of vapor–liquid equilibrium, vapor–liquid–liquid equilibrium, liquid–liquid equilibrium, an upper and lower critical endpoint and mixture critical points. The solubility and volume expansion of CO₂ in 1-methylimidazole, 1-bromohexane, a 1:1 mixture of 1-methylimidazole and 1-bromohexane and [HMIm][Br] was determined at 313.15 K and 333.15 K for pressures ranging from 10 to 160 bar. The solubility of CO₂ and the volume expansion increases in the order of [HMIm][Br]  1-methylimidazole < 1:1 mixture of reactants < 1-bromohexane. The Peng–Robinson equation of state with van der Waals 2-parameter mixing rules was used with estimated critical properties to well correlate the vapor–liquid equilibrium. The results have important ramifications on the kinetics and process constraints of an actual IL synthesis with CO₂.     

离子液体1-乙基-3-甲基咪唑醋酸盐对酿酒酵母AY93161的毒性及其酒精发酵过程的影响

为了考察离子液体在由木质纤维原料制备可发酵糖中的残留对后续酒精发酵过程的影响,对离子液体1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)对酿酒酵母AY93161的毒性及其酒精发酵过程的影响进行研究。通过亚甲基蓝染色,利用OLYMPUS CX41显微镜观察不同[Emim]Ac浓度下对数生长期酵母细胞的形态结构,出芽情况及代谢活性,发现在[Emim]Ac浓度高于5 g·L^-1时,酵母细胞的形态结构会发生变化,在[Emim]Ac浓度高于0.1 g·L^-1时,随着[Emim]Ac浓度的增加,酵母的出芽速率及代谢活性降低。通过平板培养和液体悬浮培养测得[Emim]Ac对酵母的半有效浓度EC50和半抑制浓度IC50分别为4.45、7.70 g·L^-1。通过测定不同[Emim]Ac浓度下酵母酒精发酵的过程数据,发现在[Emim]Ac浓度低于0.1 g·L^-1时,对酵母酒精发酵过程几乎无影响,在[Emim]Ac浓度高于0.1 g·L^-1时,对酵母酒精发酵有抑制作用,[Emim]Ac对酵母酒精发酵的抑制作用主要是由其对菌体生长的抑制所致。     

Facile preparation for robust and freestanding silk fibroin films in a 1‐butyl‐3‐methyl imidazolium acetate ionic liquid system

Silk fibroin film (SFF) with excellent mechanical properties was prepared for the first time with Bombyx mori silk fibroin as the material and 1‐butyl‐3‐methyl imidazolium acetate ([Bmim]OAc) ionic liquid (IL) as the solvent. The aim was to understand whether the microstructure of SFF could be modified and whether the mechanical properties were improved when [Bmim]OAc IL was used as a solution. With this new system, the obtained SFF was easily peeled off of the substrate, and the silk fibroin proteins retained the α‐helix secondary structure (silk I). Further test results show that the tensile strength (126.8–129.7 MPa) and anti‐UV performance were stronger than the silk fibroin regenerated by traditional ways. Therefore, this study provided and identified a new method with [Bmim]OAc to obtain SFF with strong mechanical properties. This facile preparation and related SFF with excellent mechanical strength could have potential applications in biocompatible implants, synthetic coatings for artificial skin, and many other areas. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42822.     

New polymer electrolytes based on ether sulfate anions for lithium polymer batteries: Part I. Multifunctional ionomers: Conductivity and electrochemical stability

New lithium conducting ionomers based on commercial polyethers were synthesized by chemical modification in order to incorporate not only the anionic function on the polymer backbone but also polar aprotic and (or) protic groups improving both the salt dissociation and the anion-solvating ability of the multifunctional copolymers. The choice of environmentally friendly rather than perfluorinated anionic functions did not appear to compromise for the ionic conductivity. Lastly, the preliminary results on the use of an electrochemically stable and relatively cheap additive sparteine appear promising and could be generalized to a variety of polymer electrolytes for lithium batteries.     

An in situ scanning tunneling microscopic study of electrodeposition of bismuth on Au(1 1 1) in a 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid: Precursor adsorption and underpotential deposition

In this article, the electrodeposition of Bi on Au(1 1 1) surface in the underpotential region in BMIBF₄ ionic liquid containing BiCl₃ is studied by cyclic voltammetry and in situ scanning tunneling microscopy (STM). The cyclic voltammogram shows several cathodic and anodic peaks associated with underpotential deposition (UPD) of Bi and dissolution of the UPD deposit, respectively, in the potential region between −0.38 and −0.7 V versus Pt quasi-reference electrode. In situ STM results indicate there is a BiCl₃ precursor adsorption stage prior to the Bi UPD. The adsorption of BiCl₃ leads to the formation of unique hexagonal and trigonal supramolecular assembly with a Au(1 1 1)(10 × 10) structure. The initial stage of Bi UPD proceeds with the formation of Au(1 1 1)(7 × 7) R21.8° adlayer structure composed of Bi trigonal clusters at −0.5 V. A structural transformation occurred at −0.6 V resulting in a unique “zipper-like” double-chain pattern composed of well-aligned Bi trigonal clusters which can be denoted by Au(1 1 1)(5 × 25√3/3) structural model. The trigonal clusters composed of six Bi atoms seem to be the main characteristic elemental units of Bi UPD adlayer regardless of underpotential shift. These features are dramatically different from those observed in Bi(III)-containing acidic aqueous solutions as well as in chloroaluminated ionic liquid, but are similar to those of Sb UPD in BMIBF₄ ionic liquid, which reveals profound solvent effects on the electrodeposition of semimetals.