A. M. Pimenova

The Influence of Water on the Physicochemical Characteristics of 1-Butyl-3-methylimidazolium Bromide Ionic Liquid

A modified synthesis of 1-butyl-3-methylimidazolium bromide (BMImBr) was suggested and performed, and some physicochemical properties of the product containing 0.64–13.6 wt % water were determined. Water increased the electrical conductivity and decreased the viscosity and melting point of the substance but weakly influenced its density. Water in amounts of 5–8 wt % (45–50 mol %) caused structural changes. The BMImBr · 0.5H2O crystal hydrate was found to be stable thermodynamically.

Electrochemical behavior of copper in 1-butyl-3-methylimidazolium bromide-copper(II) bromide binary ionic liquid

The methods of potentiometry, voltammetry, and gravimetry are used to study the electrochemical behavior of copper in the BMImBr-CuBr2 ionic liquid (0–30.5 mol % CuBr2). It is shown that electrochemical reduction of copper(II) occurs irreversibly, in two one-electron stages (transfer coefficient α of the cathodic process are 0.58 and 0.46, accordingly, for the first and second stages). Diffusion coefficients of copper-containing ions DCu(II) at 60°C are 1.3 × 10−7 and 1.6 × 10−7 cm2 s−1 in melts with the CuBr2 concentration of 0.1 and 1.5 mol kg−1 of BMImBr, accordingly. High (up to 98%) deposition efficiency and high-quality copper deposit can be obtained in the potential range of −2.0 to −1.8 V (vs. a platinum quasireference electrode). It is found that the copper corrosion rate grows at an increase in the CuBr2 concentration in the binary melt and is comparable with that in aqueous solutions of H2SO4-CuSO4.

Kinetics of anodic oxidation of copper in an ionic liquid composed of 1-butyl-3-methyl imidazolium bromide monohydrate

Cyclic voltammetry, chronopotentiometry, and gravimetry were used to study the electrochemical oxidation of copper in an ionic liquid, 1-butyl-3-methyl imidazolium bromide monohydrate.

Electrochemical Properties of the System of Ag—1-Butyl-3-Methylimidazolium Bromide Low- Temperature Ionic Liquid—Silver Bromide

The methods of potentiometry, electrochemical impedance spectroscopy, cyclic voltammetry, and gravimetry were used to study the electrochemical behavior of a silver electrode in low-temperature ionic liquids of BMImBr and BMImBr—AgBr, and also the process of cathodic reduction of Ag(I) compounds out of a BMImBr—AgBr melt. It is shown that an AgBr film is formed on the silver surface and its properties are determined by the ionic liquid composition. It is found that the process of silver electrodeposition from a BMImBr—AgBr binary alloy occurs irreversibly, at a high current efficiency (up to 100%) and a good quality of the deposit at low current densities. At 70°C, the transfer coefficients of the cathodic process (α = 0.56 and 0.16) and diffusion coefficients (DAg(I) = 0.48 × 10−7 cm2/s and 3.3 × 10−7 cm2/s) of silver-containing ions are determined in ionic liquids with the AgBr concentration of 0.81 and 1.53 mol/kg BMImBr, accordingly.

Electrochemical oxidation of tantalum and niobium in 1-butyl-3-methylimidazolium bromide melt containing water admixtures

The niobium and tantalum anodic oxidation is studied using electrochemical methods in a ionic liquid, 1-butyl-3-methylimidazolium bromide (BMImBr), containing water admixtures. It is found that resistive oxide layers are formed on the metal surface in the polarization process and their growth follows the complicated parabolic or inverse logarithmic laws. It is shown that under the given conditions, the chemical stability of oxide layers on niobium is considerably lower than that on tantalum.

Electrochemical properties of 1-butyl-3-methylimidazolium bromide melt containing water impurities

AbstractThe effect of a water impurity (1.8–10 wt %) on the conductivity of the ionic liquid-H2O binary system was studied in a wide temperature range. It was shown that the interaction between components is characteristic of this system, and the molar ratio of components 1: 1 is boundary between the structures of solution and melt. The basic kinetic features of electrochemical reduction of water of the BMImBr-H2O binary system were determined by voltammetry with linear potential sweep. The transfer coefficient for the cathodic process (α = 0.46) and H2O molecule diffusivities were determined depending on the water content (

Electroconductivity of low-temperature ionic liquid 1-butyl-3-methylimidazolium bromide-silver bromide. Effects of AgBr concentration and temperature

D_{H_2 O}

Properties of 1-n-butyl-3-methylimidazolium bromide–copper (II) bromide ionic liquid as electrolyte for electrochemical deposition of copper

= (0.2–1.3) × 10−10 cm2s−1).