Ionic electrolytes

Ratner, M.A. (2000), Polymer Electrolytes Ionic Transport Mechanisms and Relaxation Coupling, MRS Bull. 25(3), 31. 

C. Karavasilis, S. Bebelis, and C.G. Vayenas, Selectivity Maximization of Ethylene Epoxidation via NEMCA with Zirconia and (3"-Al203 Solid Electrolytes, Ionics 1, 85-91 (1995). 

Generally, in solid electrolytes, ionic conductivity is predominant (( = 1) only over a limited chemical potential. The electrolytic conductivity domain is an important factor limiting the application of solid electrolytes in electrochemical sensors. 

The terminology applied in the different papers might vary. For example, both the terms buffer concentration and electrolyte concentration are frequently used and usually refer to the same. The same occurs for the terms buffer pH and electrolyte pH, and buffer ionic strength and electrolyte ionic strength. However, for the exact meaning or practical implications, we refer to the corresponding literature. 

Examined factors were buffer or electrolyte concentration,buffer or electrolyte pH,7i,73,74 Q). electrolyte ionic strength, " rinse times,capillary temperature,... 

Electrolytes Ionic solutes that conduct electricity within a solution. 

The two basic kinds of nickel—zinc main separators are the membranes and the microporous separators. Membrane separators are those in which ionic transport occurs through the interaction of the hydrophilic groups attached to the polymer with the ionic groups in the electrolyte. Ionic transport through mi-... 

Total molar conductivity of electrolyte Ionic molar conductivity Chemical potential... 

Many reactions, particularly those that involve ionic compounds, take place in aqueous solution. Substances whose aqueous solutions contain ions and therefore conduct electricity are called electrolytes. Ionic compounds, such as NaCl, and molecular compounds that dissociate substantially into ions when dissolved in water are strong electrolytes. Substances that dissociate to only a small extent are weak electrolytes, and substances that do not produce ions in aqueous solution are nonelectrolytes. Acids dissociate in aqueous solutions to yield an anion and a hydronium ion, H30 +. Those acids that dissociate to a large extent are strong acids those acids that dissociate to a small extent are weak acids. 

Water vapour is produced at the anode diluting the fuel. The hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR) occur at the triple phase boundary (TPB) zone where the electrode (electronic phase), electrolyte (ionic... 

Combined with densities, molecular weights, and transference numbers (fractions of the current carried by the various ionic constituents), the conductivity yields the relative velocities of the ionic constituents under the influence of an electric field. The mobilities (velocity per unit electric field, cm2 s-1 V-1) depend on the size and charge of the ion, the ionic concentration, temperature, and solvent medium. In dilute aqueous solutions of dissociated electrolytes, ionic mobilities decrease slightly as the concentration increases. The equivalent conductance extrapolated to zero electrolyte concentration may be expressed as the sum of independent equivalent conductances of the constituent ions... 

In the high-frequency range (/>10Hz), the series resistance variation with temperature can be neglected. In the low-frequency range, the ESR increases when the temperature decreases [54], This is caused by the electrolyte ionic resistance RT which is strongly influenced by the temperature. Above 0°C Rt varies slowly with the temperature. Below 0°C, the temperature dependency is more... 

Comparing this approach with previous work - except the studies on solid electrolytes - ionic liquids have two distinct advantages over aqueous or organic solvents (i) Due to their extremely low vapor pressure ionic liquids can be used without any problem in standard plasma vacuum chambers, and the pressure and composition in the gas phase can be adjusted by mass flow controllers and vacuum pumps. As the typical DC or RF plasma requires gas pressures of the order of 1 to 100 Pa, this cannot be achieved with most of the conventional liquid solvents. If the solvent has a higher vapor pressure, the plasma will be a localised corona discharge rather than the desired extended plasma cloud, (ii) The wide electrochemical windows of ionic liquids allow, in principle, the electrodeposition of elements that cannot be obtained in aqueous solutions, such as Ge, Si, Se, A1 and many others. Often this electrodeposition leads to nanoscale products, as shown e.g. by Endres and coworkers [60]. 

Another key limiting factor for the conversion of C02 is the low mass-transfer rates of C02 at the electrode/catalyst surface, which is exacerbated by the low solubility of C02 in many electrolytes. Ionic liquids [34] may help to solve this problem, as Zhao et al. [35] originally proposed. 

Ionic current — The propagation of charge by ions. Ionic currents can flow between electrodes in an - electrolyte solution, in - solid electrolytes, in molten salts (including - ionic liquids) and also in plasmas. In solid electrolytes ionic currents can be accompanied by electronic currents, whereas they will be always accompanied by electronic currents in plasmas. 

UV-Vis spectroscopy — Electronic absorption in the UV-Vis range by species generated during electrochemical reactions or being present at the electrochemical interface between the electronically conducting electrode and an ionically conducting phase (electrolyte solution, molten electrolyte, ionic liquid, solid electrolyte) can be studied with in situ UV-Vis spectroscopy in various modes [i-iii] ... 

Thin layer — A layer of -+ electrolyte solution (molten salt electrolyte, - ionic liquid) of about 2 to 100 pm thickness is commonly treated as a thin layer because of particular properties and behavior. In bulk - electrolysis methods the amount of convertible species contained in a thin layer is very limited, thus exhaustive electrolysis becomes feasible. In numerous spectroelec-trochemical setups the electrolyte solution confined between the electrode surface under investigation and the... 

Quaternary phosphonium salts are organophosphorous compounds used as Wittig olefination reagents, phase transfer catalysts, electrolytes, ionic liquids, and as surface active reagents. Their preparation involves the C-P bond formation in tertiary phosphines. We envisaged that addition of phosphines to unsaturated compounds should be preferable as compared to the conventional method using a substitution reaction of organohalogen compounds (Scheme 1). In this chapter, we describe our recent study on this subject. 

When an electrode (electronic conductor) is contacted with an electrolyte (ionic conductor), it shows some potential and attracts ions with opposite sign, forming electrical double-layer at the electrode/electrolyte interface, as shown in Figure 17. lu. Increasing its electrode potential causes further adsorption of ions... 

The terms pure liquid electrolyte, ionic liquid, fused salt, and molten salt are used synonymously. 

A.L. Loeb, J.Th.G. Overbeek and P.H. WIersema. The Electrical Double Layer around a Spherical Colloid Particle, M.I.T. Press (1961). (Covers symmetrical and asymmetrical electrolytes, ionic components of charge and Gibbs energies.)... 

An operational definition endorsed by the International Union of Pure and Applied Chemistry (lUPAC) and based on the work of Bates determines pH relative to that of a standard buffer (where pH has been estimated in terms of p"H) from measurements on cells with liquid junctions the NBS (National Bureau of Standards) pH scale. This operational pH is not rigorously identical to p H defined in equation 30 because liquid junction potentials and single ion activities cannot be evaluated without nonthermodynamic assumptions. In dilute solutions of simple electrolytes (ionic strength, I < 0.1) the measured pH corresponds to within 0.02 to p H. Measurement of pH by emf methods is discussed in Chapter 8. 

Electrolyte Ionic Resistivity (G-cm) Maximum Membrance Thickness (mm)... 

The electrolysis products of different carboxylates have been compared with the ionization potentials of the intermediate radicals. From this it appeared that alkyl radicals with gas-phase ionization potentials smaller than 8 eV mainly lead to carbenium ions. Accordingly, a-substituents such as carboxy, cyano or hydrogen support the radical pathway, whilst alkyl, cycloalkyl, chloro, bromo, amino, alkoxy, hydroxy, acyloxy or aryl more or less favor the route to carbenium ions. Besides electronic effects, the oxidation seems also to be influenced by steric factors. Bulky substituents diminish the extent of coupling. The main experimental factors that affect the yield in the Kolbe electrolysis are the current density, the pH of the electrolyte, ionic additives, the solvent and the anode material. 

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