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A new approach for the formation of Al–Ti alloy in 1-ethyl-3-methylimidazolium chloride (EmimCl) was investigated. The dissolution of titanium electrodes in presence of EmimCl:AlCl3 was performed at various potentials to understand the effect of voltage on the reaction rate. It was observed that at low potentials, the presence of titanium hinders the reaction and diminishes the formation of aluminum and aluminum–titanium alloy at the cathode. However, at higher potentials there was substantial formation of Al3Ti alloy. To understand the reaction mechanism during the electrolysis, the electrolyte was characterized using Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–vis) and nuclear magnetic resonance (NMR) techniques. The material on the cathode was characterized using scanning electron microscope (SEM) and Energy dispersive X-ray (EDX) techniques. From the above analysis it was found that titanium forms a complex with aluminum and also assists in formation of AlCl4− phase in the acidic ionic liquid.

Vapour–liquid equilibrium data (water activity, vapour pressure, osmotic coefficient, and activity coefficient) of the mixed electrolyte aqueous solutions, 1-ethyl-3-methylimidazolium chloride, (EmimCl) + tri-potassium phosphate, EmimCl + potassium carbonate, EmimCl + potassium chloride and their corresponding binary aqueous solutions have been measured by the isopiestic method at a temperature of 298.15 K. The osmotic coefficients for binary aqueous solutions were correlated to the Pitzer, modified Pitzer and TCPC models. The osmotic coefficient of mixed electrolyte with common anion was correlated to the Pitzer model. From these data, the corresponding mean activity coefficients, γ ± , have been calculated. The activity coefficients of mixed electrolytes were calculated by Scatchard’s neutral electrolyte method. A modified Pitzer model has been used to predict the osmotic and activity coefficients of mixed electrolyte solution with common anion.

In this study, Al was electrodeposited on a platinum substrate at room temperature from an ionic liquid bath of EMIC containing AlCl3 using potentiostatic polarization (PP), galvanostatic polarization (GP), monopolar current pulse polarization (MCP) and bipolar current pulse polarization (BCP). Transition of current or potential during galvanostatic or pulse polarization revealed that the initial stage of the deposition process was controlled by a nucleation process depending on the polarization condition. For example, the average size of Al deposits decreased with increasing current density in the case of GP. FE-SEM observation showed that dense and compact Al deposits with a smooth surface were obtained by the current pulse method. Roughness factor evaluated from electrochemical impedance measurement confirmed the smooth surface of these deposits. Adhesion strength of Al deposits was greatly improved using BCP in which an anodic pulse was combined with a cathodic pulse for electrodeposition. In this study, the optimal parameters for BCP were found to be IC = −16.0 mA cm−2, IA = 1.0 mA cm−2, rC (duty ratio) = 0.5, and f = 2 Hz. The mechanisms of electrodeposition by these three methods are discussed.

We studied the coordination environment about Cu(II) in a pure ionic liquid, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl), and in binary mixtures of this compound with water across the entire range of compositions, using a combination of X-ray absorption fine structure (XAFS), ultraviolet-visible (UV-vis) spectroscopy, and electronic structure calculations. Our results show a series of stages in the ion pairing of the divalent cation, Cu(II), including the contact ion pairing of Cu(2+) with multiple Cl(-) ligands to form various CuCl(n)((2-n)) polyanions, as well as the subsequent solvation and ion pairing of the polychlorometallate anion with the EMIM(+) cation. Ion-pair formation is strongly promoted in [EMIM]Cl by the low dielectric constant and by the extensive breakdown of the water hydrogen-bond network in [EMIM]Cl-water mixtures. The CuCl(4)(2-) species dominates in the [EMIM]Cl solvent, and calculations along with spectroscopy show that its geometry distorts to C(2) symmetry compared to D(2d) in the gas phase. These results are important in understanding catalysis and separation processes involving transition metals in ionic liquid systems.

An Al coating film, electrodeposited on a Mg alloy from aluminum chloride–1-ethyl-3-methylimidazolium chloride (AlCl 3 –EMIC) ionic liquid, effectively prevents the substrate from rapid corrosion in a hostile environment. The thickness of the Al film can be easily determined by controlling the total cathodic charge applied, because the current efficiency of the electrodeposition reaction is close to 100%. Heat treatment at 450 °C under an argon atmosphere for 10 min causes an inter-diffusion at the Al/Mg interface, optimizing the protective performance of the coating film. Prolonging heating leads to a Mg 17 Al 12 intermetallic phase and a Mg solid solution phase to be formed at the expense of the deposited Al film. This phase transformation gives rise to a degradation in the corrosion resistance of the Al-coated sample.

The corrosion properties of carbon steel (CS), 304 stainless steel (304 SS), and pure titanium (Ti) are first studied in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid (IL). An active-to-passive transition behavior was clearly observed for CS. The 304 SS exhibited the best stability among the materials; no considerable corrosion was recognized even in this high-chloride environment. In contrast, although Ti resists corrosion in ambient environments, it was not passivated in the IL and became severely corroded under an anodic applied potential. The material corrosion behaviors and mechanisms in the non-aqueous, low-oxygen, and high-halogen-containing IL are completely different from those in traditional aqueous solutions. Keywords: Ionic liquid, Corrosion behavior, Titanium, Stainless steel, Carbon steel

A recently improved ionic liquid force field was used to compute the viscosity for binary and ternary mixtures of 1-ethyl-3-methylimidazolium chloride ([emim][Cl]) with water, acetonitrile, and glucose. For the same systems, experimental viscosity data are provided. The simulation and experimental results were in reasonable agreement. Simulations consistently overestimate the viscosities for the mixtures of [emim][Cl] and glucose while the viscosities of the mixtures of glucose and water are well reproduced. Both experiments and simulations show that the addition of acetonitrile reduces the viscosity of a solution of [emim][Cl] and glucose by more than an order of magnitude.

The co-deposition of Al and Zn on AZ91D magnesium alloy from a Lewis acidic aluminum chloride–1-ethyl-3-methylimidazolium chloride (AlCl3–EMIC, with a molar ratio of 60:40) ionic liquid containing 1 wt% ZnCl2 at room temperature was studied. The effect of potential on the deposition rate, the microstructure and the chemical composition of the deposit was explored. The experimental results show that the simultaneous deposition of Al and Zn on Mg alloy can be achieved under properly controlled potential conditions. The deposition rate increased while the amount of Zn existing in the coating decreased with increasing negative deposition potential. In the ionic liquid studied, a uniform chemical composition of the coating was obtained when the deposition was performed at −0.2 V (vs. Al).

The influence of reaction atmosphere on the liquefaction and depolymerization of wood in an ionic liquid, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), has been systematically studied. The wood samples were treated with [C2mim][Cl] at 120°C under various atmospheres such as oxygen, nitrogen, and carbon dioxide, both dried and humidified. The percentage of residue after the treatment shows that oxygen considerably accelerates the liquefaction of wood in [C2mim][Cl], and humidity hardly affects liquefaction under any atmosphere. Gel permeation chromatography (GPC) and high performance liquid chromatography (HPLC) analyses on the solubilized compounds in [C2mim][Cl] indicate that oxygen and humidity enhance the depolymerization of the wood component. Thus, the reaction atmosphere was revealed to influence, and 1be capable of controlling, the reaction of wood in [C2mim][Cl].

Reaction of Japanese beech (Fagus crenata) in an ionic liquid, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), which can dissolve cellulose, was investigated. Although both lignin and polysaccharides such as cellulose and hemicelluloses can be liquefied at a treatment temperature of around 100°C, the liquefaction of polysaccharides mainly occurs at the beginning of the treatment with [C2mim][Cl]. Cellulose crystallinity in the wood was gradually broken down as the treatment continued. The solubilized polymers were depolymerized to low molecular weight compounds. The results indicate that [C2mim][Cl] is an effective solvent and reagent for the liquefaction of wood components and subsequent depolymerization of them.

Porous anodic alumina template is synthesized by electrochemical anodization of aluminum and used to grow cobalt nanowires. The cobalt nanowires produced by direct current electrodeposition are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and physical property measurement system. Test results indicate that the average diameter of cobalt nanowires is about 45 nm, which is generally the same as the pore diameter of porous anodic alumina template, and the cobalt nanowires electrodeposited from mixture of 1-ethyl-3-methylimidazolium chloride ionic liquid and ethylene glycol have a smoother surface and better magnetic properties than cobalt nanowires electrodeposited from aqueous solution, and they show a better squareness. Therefore it can be concluded that the cobalt nanowires electrodeposited from mixture of 1-ethyl-3-methylimidazolium chloride ionic liquid and ethylene glycol using porous anodic alumina template can be used as a perpendicular magnetic recording film.

The electrodeposition of AlIn, AlSb, and AlInSb alloys was examined at copper rotating wire electrodes in the Lewis acidic 66.7–33.3 mol.% (m/o) aluminum chloride–1–ethyl–3–methylimidazolium chloride room-temperature ionic liquid. The Sb content in the AlSb binary electrodeposits depended on the applied current density, but the In content in the AlIn alloys was quite low, ∼ 1 at.% (a/o), and independent of the current density. Variation of the partial current densities for the In and Sb during AlInSb deposition suggested that the deposition of a second phase rich in In and Sb, possibly InSb, occurs simultaneously at higher applied current densities. However, no X-ray diffraction patterns are apparent in these deposits other than that for face-centered cubic Al. Thus, the AlInSb deposit most likely consists of a non-equilibrium mixture of Al x In y Sb 100– x – y and amorphous or nanocrystalline InSb. The AlInSb alloy semiconductor deposits prepared during this investigation exhibited photocatalytic behavior and could catalyze the photodecomposition of water under illumination with visible light.

Electrodeposition of a metallic Al layer on a Mg alloy from a Lewis acidic Al chloride–1-ethyl-3-methylimidazolium chloride (EMIC) ionic liquid has been carried out at room temperature. The effects of the AlCl3 to EMIC molar ratio, in the range from 50%–50% to 60%–40%, on the electrodeposition characteristics were investigated. Scanning electron microscopy, X-ray energy dispersive spectroscopy, and X-ray diffractometry were used to examine the surface morphology, the chemical composition, and the crystal structure of the deposited layers prepared in the ionic liquids with different AlCl3 to EMIC ratios. The improvement of corrosion resistance of a Mg alloy to the Al surface coating was also evaluated by means of various electrochemical methods. The electrochemical impedance spectroscopic data indicated that while a bare Mg alloy had a polarisation resistance of only 470 Ω cm2 in 3˙5 wt-% NaCl solution, the Al coated sample deposited in the ionic liquid with 60%AlCl3 showed a resistance as high as ...

We report here a nonenzymatic sensor by using a nanoporous platinum electrode to detect glucose directly. The electrode was fabricated by electrochemical deposition and dissolution of PtZn alloy in zinc chloride-1-ethyl-3-methylimidazolium chloride (ZnCl2-EMIC) ionic liquid. Both SEM and electrochemical studies showed the evidences for the nanoporous characteristics of the as-prepared Pt electrodes. Amperometric measurements allow observation of the electrochemical oxidation of glucose at 0.4 V (vs. Ag/AgCl) in pH 7.4 phosphate buffer solution. The sensor also demonstrates significant reproducibility in glucose detection; the higher the roughness factor of the Pt electrode, the lower the detection limit of glucose. The interfering species such as ascorbic acid and p-acetamidophenol can be avoided by using a Pt electrode with a high roughness factor of 151. Overall, the nanoporous Pt electrode is promising for enzymeless detection of glucose at physiological condition.

The electrodeposition of nickel and nickel–zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel–zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel–zinc alloys are dependent on the deposition potential. For the Ni–Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni–Zn was always less than 50 atom%.

This work describes the fabrication of porous some metal films by electrochemical formation and electrochemical dealloying of Zn alloys in a ZnCl2-EMIC ionic liquid, without using hazardous acids or bases. The effects of the amounts of deposited zinc, deposition potential, current, and temperature on the pore structure are described. It is worth to note that in this process, the zinc(II) species in the IL was consumed during the electrodeposition step but was recovered during the electrochemical dealloying step, making the IL re-usable.

A dense and adhesive Al layer was successfully electrodeposited on a Mg alloy in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid. The corrosion resistance of the uncoated and Al-coated samples was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization measurements in 3.5 wt% NaCl solution. It was confirmed that the protective Al layer significantly reduces the corrosion rate of the Mg alloy. However, the deposition potential was a crucial factor that governed the structure and therefore the protection capability of the Al layer. Keywords: Magnesium alloy, Corrosion, Electrodeposition, Al-coating, Ionic liquid

Glucose is an important carbohydrate, relevant both for its biological functions and as a raw material for industrial processes. As a monomer of cellulose, the most abundant biopolymer, it is an alternative feedstock for fuels and chemicals in the biorefinery framework. Since glucose is often used and processed in aqueous solutions, it is important to understand the structural, volumetric, and dynamic properties of aqueous glucose solutions at varying concentrations. Molecular dynamics (MD) simulations are an effective means for computing the properties of liquid solutions, but the technique relies upon accurate intermolecular potential functions (i.e., \"force fields\"). Here we evaluate the accuracy of the recently developed GROMOS 56A(CARBO) glucose force field for its ability to model the density, viscosity, and self-diffusivity of aqueous glucose solutions as a function of concentration. We also compute different structural properties, including hydrogen bonds, radial and spatial distribution functions, and coordination numbers. The results show that the force field accurately models the density and viscosity of dilute solutions up to a glucose mole fraction of 0.1. At higher glucose concentrations, the force field overestimates the experimental density and viscosity. By analyzing the liquid structure, it is found that the glucose molecules tend to associate at higher concentrations, which leads to deviation from the experimental results. This suggests that, while the GROMOS 56A(CARBO) force field performs well for highly dilute glucose solutions (conditions under which it was developed), it is not appropriate for carrying out simulations of more concentrated glucose solutions. It is possible to obtain much more accurate densities and viscosities at high glucose concentrations by uniformly reducing the partial charges on glucose by 20%, which attenuates the self-association tendencies of glucose.

The electrodeposition and surface morphology of aluminium on tungsten (W) and aluminium (Al) electrodes from 2 : 1 molar ratio AlCl 3 –[EMIm]Cl ionic liquids were investigated. Analyses of the chronoamperograms indicate that the deposition process of aluminium on W substrates was controlled by instantaneous nucleation with diffusion-controlled growth, while the deposition processes of aluminium on Al electrodes were found to be associated with kinetic limitations. Constant potential deposition experiments showed that the electrodeposits obtained on both W and Al electrodes between − 0.10 and − 0.40 V (vs. Al(III)/Al) are dense, continuous and well adherent. Dense aluminium deposits were also obtained on Al substrates using constant current deposition between 10 and 70 mA/cm 2 , and the current efficiency was found to be dependent of the current density varying from 85% to 100%.

Voltammetry at a glassy carbon electrode was used to study the electrochemical co-deposition of Pd–In from a chloride-rich 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate air-stable room temperature ionic liquid at 120 °C. Deposition of Pd alone occurs prior to the overpotential deposition (OPD) of bulk In. However, underpotential deposition (UPD) of In on the deposited Pd was observed at the potential same as the deposition of Pd. The UPD of In on Pd was, however, limited by a slow charge transfer rate. Samples of Pd–In alloy coatings were prepared on nickel substrates and characterized by energy dispersive spectroscope (EDS), scanning electron microscope (SEM) and X-ray powder diffraction (XRD). The electrodeposited alloy composition was relatively independent on the deposition potential within the In UPD range. At more negative potentials where the OPD of Pd–In has reached mass-transport limited region, the alloy composition corresponds to the Pd(II)/In(III) composition in the plating bath. The Pd–In alloy coatings obtained by direct deposition of Pd and UPD of In on the deposited Pd appeared to be superior to the Pd–In alloys that were obtained via the co-deposition of Pd and bulk In at OPD potentials.

The electrodeposition of palladium–silver alloys was investigated in a basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate ionic liquid containing Pd(II) and Ag(I). Cyclic voltammetry experiments showed that the reduction of Ag(I) occurs prior to the reduction Pd(II). Both electrodeposition processes require nucleation overpotential. Energy-dispersive spectroscopy data indicated that the composition of the Pd–Ag alloys could be varied by deposition potential and concentrations of Pd(II) and Ag(I) in the solution. The Pd content in the deposited Pd–Ag alloy increased with decreasing deposition potential and the Pd mole fraction in the plating bath. At potentials where the deposition of both Pd and Ag was mass-transport limited, the Pd/Ag ratio in the electrodeposited alloys was slightly less than the Pd(II)/Ag(I) ratio in the ionic liquid due to the smaller diffusion coefficient of Pd(II). Scanning electron micrographs of the electrodeposits showed that in general, the Pd–Ag alloys were nodular and become more compact upon increasing the temperature up to 120 °C.

Voltammetry at a glassy carbon electrode was used to study the electrochemical deposition of Cd–Te from the Lewis basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate air-stable room temperature ionic liquid between 80 °C and 140 °C. Deposition of tellurium alone occurs through a four-electron reduction of Te(iv) to Te which could be further reduced to Te(-ii) at a more negative potential. The Cd–Te electrodeposits could be obtained by the underpotential deposition (UPD) of Cd on the deposited Te. The UPD of Cd on Te was, however, limited by a slow charge transfer rate. Samples of Cd–Te electrodeposits were prepared on tungsten and titanium substrates and characterized by energy dispersive spectroscope (EDS), scanning electron microscope (SEM), and X-ray powder diffraction (XRD). The results showed that an excess amount of Cd(ii) was required in order to prepare CdTe codeposits with a Cd/Te atomic ratio approached 1/1. The deposit composition was independent of the deposition potential within the Cd UPD range. Raising the deposition temperature increased the UPD rate of Cd and promoted the formation polycrystalline CdTe.

The electrodeposition of PtZn from a Lewis acidic 40–60 mol% zinc chloride–1-ethyl-3-methylimidazolium chloride ionic liquid containing PtCl 2 was investigated at polycrystalline tungsten substrates at 90 °C. Cyclic voltammetric data indicates that Pt(II) was reduced at a potential slightly more positive than Zn(II) was. The Pt–Zn electrodeposits exhibited multiple anodic stripping waves. The Zn-dominant deposits were stripped at a potential less positive than that of the Pt-dominant deposits. Energy-dispersive spectroscopy and scanning electron microscopy data indicated that the composition and morphology of the electrodeposited Pt–Zn alloys were affected by the deposition potential and the Pt(II) concentration in the plating solution. The electrodeposition of Zn at a Pt substrate also produced surface Pt–Zn alloys. The Pt of the electrochemically prepared Pt–Zn alloys was easier to oxidize than the bulk Pt substrate.

The electrochemistry of indium species was investigated at glassy carbon, tungsten and nickel electrodes in a basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate ionic liquid. Amperometric titration experiments suggest that In(III) chloride is complexed as [InCl 5 ] 2 - in this ionic liquid. The electrochemical reduction of [InCl 5 ] 2 - to indium metal is preceded by overpotential driven nucleations. The effective anodic dissolution of indium to indium(III) requires, however, the presence of sufficient chloride ions at the electrode surface. The electrodeposition of indium at glassy carbon and tungsten electrodes proceeds via three-dimensional instantaneous nucleation with diffusion-controlled growth of the nuclei. At the nickel electrode, the deposition proceeds via three-dimensional progressive nucleation with diffusion-controlled growth of the nuclei. Raising the deposition temperature decreases the average radius of the individual nuclei, r. Scanning electron microscopic and x-ray diffraction data indicated that bulk crystalline indium electrodeposits could be prepared on nickel substrates within a temperature range between 30 and 120 °C.

Electric conductivities of 50-50 mol% ZnCl2-EMIC and its mixtures with 0.6714 mol% PdCl2 room-temperature molten salts (RTMS) have been measured by a computerized system based on a d.c. four-probe method. The conductivity of the former is greater than that of the latter. These conductivities are well fitted by Arrhenius equations and the activation energies are calculated to be 25.22 and 26.28 kJ/mol, respectively. Cyclic voltammetry for the ZnCl2-EMIC-PdCl2 melt has been performed on Pt and Cu working electrodes. The cathodic reduction waves of Pd2+ and Zn2+ species and the oxidation waves for Zn-Pd alloys rich in Zn and Pd have been observed for the cyclic voltammograms on the Pt working electrode. The deposition potentials have been measured to be −0.7 V and −1.3 V on the Cu substrate. The morphology and composition of the electrodeposited layers obtained under different conditions have been analyzed by SEM and EDS, respectively; layers with a finer (about 300 - 500 nm), denser and higher Pd content have been obtained by pulse plating on the Cu sheet at ton/toff = 3/1 under −0.7 V at 80 °C. The XRD patterns also reveal that the structure of these deposited layers can be regarded as amorphous. Tafel polarization curves of the electrodeposited layers in 3.5 wt% NaCl solution have been drawn. The results indicate that the Zn-Pd alloy deposits have much higher corrosion resistance and protection efficiency than the Zndeposited layer; the corrosion potentials shift positively by about 700 ∼ 950 mV. Furthermore, the pulse plating has a better performance than the direct current plating, and the reason is discussed.

The electrochemical behavior of vanadium(II) was examined in the 66.7-33.3 mole percent aluminum chloride-1-ethyl-3-methylimidazolium chloride molten salt containing dissolved VCl2 at 353 K. Voltammetry experiments revealed that V(II) could be electrochemically oxidized to V(III) and V(IV). However at slow scan rates the V(II)/V(III) electrode reaction is complicated by the rapid precipitation of V(III) as VCl3. The reduction of V(II) occurs at potentials considerably negative of the Al(III)/Al electrode reaction, and Al-V alloys cannot be electrodeposited from this melt. However electrodeposition experiments conducted in VCl2-saturated melt containing the additive, 1-ethyl-3-methylimidazolium tetrafluoroborate, resulted in Al-V alloys. The vanadium content of these alloys increased with increasing cathodic current density or more negative applied potentials. X-ray analysis of Al-V alloys that were electrodeposited on a rotating copper wire substrate indicated that these alloys did not form or contain an intermetallic compound, but were non-equilibrium or metastable solid solutions. The chloride-pitting corrosion properties of these alloys were examined in aqueous NaCl by using potentiodynamic polarization techniques. Alloys containing ~10 a/o vanadium exhibited a pitting potential that was 0.3 V positive of that for pure aluminum.

The electrochemistry and electrodeposition of antimony were investigated on glassy carbon and nickel electrodes in a basic 1-ethyl-3-methylimidazolium chloride-tetrafluoroborate room temperature ionic liquid. Cyclic voltammetry results show that Sb(III) may be either oxidized to Sb(V) via a quasi-reversible charge-transfer process or reduced to Sb metal. Diffusion coefficients for both Sb(III) and Sb(V) species were calculated from rotating disc voltammetric data. Analysis of chronoamperometric current–time transients indicates that the electrodeposition of Sb on glassy carbon proceeded via progressive three-dimensional nucleation with diffusion-controlled growth of the nuclei. Raising the deposition temperature results in decreased average radius of the individual nuclei. Dense deposits can be obtained within a deposition temperature range between 30 to 120 °C. Scanning electron microscopy revealed dramatic changes in the surface morphology of antimony electrodeposits as a function of deposition temperature; deposits obtained at 30 °C had a nodular appearance whereas those obtained at 80 and 120 °C consisted of evenly distributed fine polygonal crystals.

Electric conductivity of the molten zinc chloride-1-ethyl-3-methylimidazolium chloride phases has been measured by a computerized system using the d.c. four-probes method. The sequence of the conductivities for the different component melts is ZnCl2-EMIC > ZnCl2-EMIC-CoCl2 > ZnCl2- EMIC-DyCl3 > ZnCl2-EMIC-CoCl2-DyCl3. The results may be explained in terms of the viscosity increase due to the complex formation. The electrochemistry and the nucleation mechanism of cobalt(II) or/and dysprosium chloride in acidic ZnCl2-EMIC melts have been investigated by cyclic voltammetry and chronoamperometry at different temperatures, respectively. The results of the SEM and VSM analyses reveal that reduction of Dy3+ to Dy2+ may have occurred, while reduction of Dy3+ to Dy(0) is conjectured to play no role. Moreover, the results of chronoamperometry experiments show that nucleation in the alloy electrodeposition is instantaneous, and that, as the applied deposition potential becomes more negative, the nucleation density increases, which rapidly shortens the time required for the diffusion zones to overlap. Electrodeposition of a Dy-Co-Zn alloy on a Ni or Cu sheet from the 50-50 mol% ZnCl2-EMIC melt containing 1.687 mol% CoCl2 and 1.114 mol% DyCl3 has been accomplished, and the morphology and the composition have been analyzed by SEM and EDS, respectively. The magnetism of the deposited layer is discussed based on the results of the VSM analysis.

Negative ion fast atom bombardment mass spectra (FAB-MS) recorded for ZnCl 2 –1-ethyl-3-methylimidazolium chloride (ZnCl 2 –EMIC) ionic liquids with various compositions indicate that various Lewis acidic chlorozincate clusters (ZnCl 3 − , Zn 2 Cl 5 − and Zn 3 Cl 7 − ) are present in ZnCl 2 –EMIC ionic liquids depending on the percentage of ZnCl 2 used in preparing the ionic liquids; higher ZnCl 2 percentage favors the larger clusters. Cyclic voltammetry reveals that the potential limits for a basic 1:3 ZnCl 2 –EMIC melt correspond to the cathodic reduction of EMI + and anodic oxidation of Cl − , giving an electrochemical window of approximately 3.0 V which is the same as that observed for basic AlCl 3 –EMIC ionic liquids. For acidic ionic liquids that have a ZnCl 2 /EMIC molar ratio higher than 0.5:1, the negative potential limit is due to the deposition of metallic zinc, and the positive potential limit is due to the oxidation of the chlorozincate complexes. All the acidic ionic liquids exhibit an electrochemical window of approximately 2 V, although the potential limits shifted in the positive direction with increasing ZnCl 2 mole ratio. Underpotential deposition of zinc was observed on Pt and Ni electrodes in the acidic ionic liquids. At proper temperatures and potentials, crystalline zinc electrodeposits were obtained from the acidic ionic liquids.

In this paper, structural evaluations of a room temperature ionic liquid, 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl), were systematically investigated at high pressures. Our Raman spectra, infrared spectra, and synchrotron X-ray diffraction investigations show that crystalline [EMIM]Cl experienced structural instabilities at high pressures and underwent at least four successive structural transitions at around 5.8, 9.3, 15.8, and 19.1 GPa, respectively. Notably, the abrupt emergence of photoluminescence from the sample at around 19.3 GPa, originated from the pressure-induced polymerization of the [EMIM]+ cations, as confirmed by the mass spectrometry experiments. Our results also indicate that high pressure significantly affected the conformational equilibrium of the [EMIM]+ cations. The structural transitions are influenced by the ion stacking modes determined by the hydrogen bonds and possibly by some chemical reactions in addition to the cation conformational isomers.

To establish an effi cient method for effective utilization of lignocelluloses, many studies on lignocellulose conversion technology have been carried out. A promising novel method is treatment with ionic liquids, which are organic salts with melting points in the vicinity of ambient temperature. Ionic liquids have many notable characteristics such as negligible vapor pressure, thermal stability, recyclability, and nonfl ammability. It has been found that some ionic liquids are able to dissolve cellulose, and there have been several reports on applications of ionic liquids to cellulose. Previous work has shown that wood components are decrystallized and depolymerized as they are liquefi ed by treatment with ionic liquids. The differences in the reaction behavior of two different wood species with ionic liquid have been studied. Signifi cant differences in lignin liquefaction behavior were explained by differences in the chemical structure of the lignin in the two wood species. The reaction atmosphere was also found to infl uence the liquefaction of wood. Although many studies on ionic liquid treatment of wood have already been reported, the resulting morphological changes of wood have not been elucidated. For that reason, in the present study, the morphological changes in wood after treatment with the ionic liquid 1-ethyl-3-methylimidazolium chloride were studied by light microscopy.

The solubility of LaCl3 in acidic AlCl3–1-ethyl-3-methylimidazolium chloride (AlCl3–EMICl) ambient temperature melts at 298 K increases as the acidity of the melts increases. When LaCl3 was dissolved in the melt (molar fraction of AlCl3, N=0.667), Raman spectra of AlCl4− and Al2Cl7− anion were observed. From these results, the dissolution reaction in the acidic melts is thought to be: 3Al2Cl7−+LaCl3⇄La(III)+6AlCl4−. Electrochemical measurements and potentiostatic electrolysis were performed in various LaCl3 saturated AlCl3–EMICl melts. The electrodeposits obtained at more negative potential than −0.18 V versus Al(III)/Al in a LaCl3 saturated acidic melt (N=0.667) were pure aluminum metal. It was suggested that lanthanum metal electrodeposits at around −1.95 V in the LaCl3 saturated melt (N=0.667) after addition of excessive LiCl and 50 mmol kg−1 of SOCl2.

The density functional theory was used to investigate the interactions between 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) and benzene/pyridine/pyrrole/thiophene. The complexes formed between [EMIM]Cl and benzene/pyridine/pyrrole/thiophene were optimized at the ωB97XD/6-31++G** level, and the optimized complexes were further analyzed by natural bond orbital, atoms in molecules, and noncovalent interaction. The calculated results show that the interaction energy between ionic liquid and benzene/pyridine/pyrrole/thiophene is in the order pyrrole > pyridine > thiophene > benzene. The major interactions between ionic liquid and benzene/pyridine/pyrrole/thiophene are hydrogen bonding and π-π interaction, accompanied by C···H, N···H, H···H, and S···H weak interactions. Both cation and anion of ionic liquid are involved in interactions with aromatic compounds.

The electrodeposition of cobalt and zinccobalt alloys on nickel, tungsten, copper, and glassy carbon electrodes was investigated in 40.0–60.0 mole percent (mol%) zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt containing cobalt(II) at 80°C. At potentials positive of 0.15 V (vs. Zn), cobalt deposition on nickel occurs via three-dimensional instantaneous nucleation with diffusion controlled growth of the nuclei. At potentials between 0.1 and 0.0 V, underpotential deposition of zinc on cobalt occurs. At potentials more negative than −0.1 V, bulk zinc deposition takes place via three-dimensional instantaneous nucleation with mixed diffusion and kinetic controlled growth. The zinc content of the ZnCo alloys was found to vary nonlinearly with the deposition potential. X-ray diffraction measurements indicate that the ZnCo deposits with a low zinc content may be amorphous and the crystalline nature of the ZnCo electrodeposits increases as the zinc content of the deposits increases. Addition of propylene carbonate co-solvent to the melt solution decreases the melting temperature of the solution and enables the electrodeposition to be performed at 40°C.

The electrochemistry of cadmium species was investigated at glassy carbon, polycrystalline tungsten and platinum electrodes in a basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate room temperature molten salt. Amperometric titration experiments suggest that Cd(II) chloride is complexed as [CdCl 4 ] 2− in this melt. [CdCl 4 ] 2− could be reduced to cadmium metal via a single-step quasi-reversible electron transfer process. On the other hand, effective dissolution of cadmium to Cd(II) is effected by the presence of sufficient chloride ions. The electrodeposition of cadmium proceeds via three-dimensional progressive nucleation with diffusion-controlled growth. The average Stokes–Einstein product for [CdCl 4 ] 2− is (2.3±0.1)×10 −10 g cm s −2 K −1 . The cadmium electrodeposits are found to be very pure and adhere well on the tungsten substrate.

A continuous and adhesive Al layer was successfully electrodeposited on a Mg alloy in aluminum chloride/1-ethyl-3-methylimidazolium ionic liquid at room temperature. Surface morphology, crystal structure, and chemical composition of the deposit were examined with a scanning electron microscope, an X-ray diffractometer, and an X-ray energy dispersive spectroscope, respectively. The corrosion resistance of the Al-coated Mg alloy was also evaluated.

The electrodeposition of the Nb3Sn alloy film from the Lewis basic NbCl5-SnCl2-EMIC melt (50 mol%

The electrodeposition of zinc on glassy carbon and nickel substrates was investigated in the 50.0–50.0 mol% zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. The electrodeposition of zinc on both electrodes required a nucleation overpotential. Analysis of the chronoamperometric current–time transients suggested that the electrodeposition of zinc on both substrates involved instantaneous three-dimensional nucleation with mixed diffusion and kinetic controlled growth of the nuclei. Scanning electron microscopic analysis indicated that the quality of the zinc electrodeposits is greatly enhanced by the addition of propylene carbonate as a `cosolvent'. It was also found that the deposits produced from plating baths with higher propylene carbonate concentrations or at higher temperatures exhibited larger grain size.

The electrochemistry of 1-ethyl-3-methylimidazolium chloride (EMIC) is important because the reduction of the 1-ethyl-3-methylimidazolium cation (EMI + ) defines the negative potential limit of room temperature molten salt electrolytes made by mixing EMIC with AlCl 3 . Since EMIC constitutes both part of the solvent and the supporting electrolyte in the molten salt, it is difficult to examine its electrochemistry quantitatively in the melt. Thus, EMIC has been studied as an analyte at a glassy carbon electrode in acetonitrile with 0.1 M tetra-n-butylammonium perchlorate (TBAP) as the supporting electrolyte. EMI + is reduced at - 2.35 V measured vs. a reference electrode consisting of a silver wire in 0.1 M TBAP/CH 3 CN. Controlled potential coulometry indicates that the reduction is a one-electron process. Subsequent voltammograms exhibit two small oxidation peaks at -0.45 and -0.65 V but no new reduction peaks. Exhaustive oxidation of these two peaks gives less than 15% as many coulombs as for the initial reduction peak, indicating that the reduction of EMI' is irreversible. Comparison of the voltammograms to those for 1-methylimidazole indicates that the reduction process does not cleave the ethyl group from the five-membered ring to give the precursor of EMIC. Mass spectra of the reduction product shows no evidence of dimer formation. The dominant product of EMI + reduction is not electroactive within the accessible voltage window of acetonitrile or the molten salt. Thus, slight degradation of the electrolyte should not interfere with the operation of EMIC/AlCl 3 molten salt cells

A series of studies on the acidity of AlCl3−1-ethyl-3-methylimidazolium chloride (EMIC) melts buffered with alkali metal chlorides were carried out. The solubility of HCl, a strong Bronsted acid in these melts, was measured in melts buffered with LiCl, NaCl, and KCl. The solubility of HCl in all three melts is 450−475 mM under 1 atm of HCl, approximately the same as that in the acidic (AlCl3-rich) melts. The relative solubility products of LiCl, NaCl, and KCl were measured, and it was found that Ksp(NaCl)/Ksp(LiCl) = 72 ± 6 and Ksp(KCl)/Ksp(NaCl) = 1000 ± 400. It is likely that the differences in the acidity of HCl in the various melts are due to the differences in the solubility product of the relevant alkali metal chlorides. These ratios are consistent with the results of previous studies on the acidity of HCl in the melts. The concentrations of the strongly Lewis acidic Al2Cl7- ion in melts buffered with LiCl were measured using an aluminum electrode. The results of the potentiometric work indicate tha...

A simple electrochemical strategy is described to prepare high surface area nanostructured platinum electrode by alloying and de-alloying of PtZn in a Lewis acidic ZnCl2-1-ethyl-3-methylimidazolium chloride ionic liquid. The resulting Pt electrode showed significantly enhanced current for hydrogen and methanol redox reactions, due to the increased surface area.