Cations mobility

Metallic Cations, mobile — Metallic bond Variable mp good conductors in solid insoluble in Na... 

A prerequisite condition for the increase in conductivity being caused by added ligands is a high association constant of the salt in the absence of added ligand. If the association constant is low, as it is for AN-based solutions, a decrease of conductivity may occur, because the Stokes radius of the solvated Li+ ion is increased by ligands with molecular diameters larger than that of AN, entailing lower cation mobility [214],... 

ZEBRA 567 energy efficiency 15 enhancement factor, lithium alloys 367 enhancing cation mobility 518 enthalpy 9... 

An important characteristic feature, common to all these reactions, is the formation of a single product (barrier) phase. In addition, the lattice structures of both reactants and products are relatively simple and information on appropriate physical and chemical properties of these substances is available. Complex iodide formation is of particular interest because of the exceptionally large cation mobilities in these phases. Experimental methods have been described in Sect. 1 and Chap. 2. 

Figure 3. Isotherms of and in (Li, K)(C03)i/2. The values of pure K(C03)i/2 are extrapolated with respect to temperature because the temperatures are less than the melting point (1164 K). (Reprinted from C. Yang, R. Takagi, K. Kawamura, and I. Okada, Internal Cation Mobilities in the Molten Binary System Li2C03-K2C03, Electrochim. Acta 32 1607-1611, Fig. 2, Copyright 1987 with permission from Elsevier Science.)...

Figure 14. Isotherms of % and La n (Y, La) 3Cl. (Reprinted from H. Matsuura, I. Okada, Y. Iwada, and J. Mochinaga, "Internal Cation Mobilities in the Molten Binary Systems (Y, La)Cl3 and (Y, Dy)Cl3, J. Electrochem. Soc.l43(l) 336,1996, Fig. 4. Reproduced by permission of the Electrochemical Society, Inc.)...

Since the membrane is permeable for cations but not for the anions A, it should intrinsically contain anions R . When these are fixed, their concentration, Cr, will remain the same everywhere. Hence in layers ( J,) and (ii) the overall cation concentration should also be the same, and the diffusion potential (which is caused by a possible difference in cation mobilities) is extremely small. In the left-hand part of the membrane system, the concentration of cations M + in each of the phases is equal to the given (invariant) concentration of anions A or, respectively the potential difference between the phases is determined, according to Eq. (5.10), by the cation concentration ratio. The right-hand part of the membrane system corresponds to the system (5.22), where phase (P) now takes the place of phase (a), and phase (rj) takes that of phase (y). As a result, we obtain for the membrane potential. 

Polymer-metal composites Cationic mobility activated electrically in membranes of the Nafion (DuPont) and Flemion (Asahi Glass) type leads to a bending response, again mimicking muscle action. 

In this paper the relation between cation mobility and catalytic activity in lean SCR NOx by CH4 on (Ag,Co)- and (Co,Ag)-FER have been studied by combining XRD Rietveld refinement in fresh and used catalysts with SCR catalytic testing performed in dry and wet conditions. UV-Vis DRS measurements were also performed. 

In this paper a detailed study on the relation between structural modifications due to reaction condition induced cation mobility and Ag,Co-FER catalytic activity, studied by XRD and UV-Vis DRS Rietveld refinement, is reported. 

The segregation or demixing is a purely kinetic effect and the magnitude depends on the cation mobility and sample thickness, and is not directly related to the thermodynamics of the system. In some specific cases, a material like a spinel may even decompose when placed in a potential gradient, although both potentials are chosen to fall inside the stability field of the spinel phase. This was first observed for Co2Si04 [39]. Formal treatments can be found in references [37] and [38],... 

Li — alkali metal. Metallic bonds present (cations, mobile electrons). Low-density metal. 

Bicarbonate Forms slightly soluble bicarbonates with cations Mobile in solution... 

A glass membrane in an electrolyte solution cannot be taken to be a homogeneous system in the direction perpendicular to the surface. When the membrane is in contact with the solution, water molecules can enter it and form a 5-100 nm thick hydrated layer [319]. The formation of this hydrated layer is actually a condition for good functioning of the glass electrode. The basic characteristics of the glass structure probably do not change in the hydrated layer, but the cation mobility increases considerably compared with the compact membrane interior... 

As discussed earlier, cations move most quickly towards the point of detection and time has to be allowed for separations to develop and the EOF should not exceed the cationic mobility by an amount which is incompatible with achieving separation. 

Carbon disulfide is isovalent to carbon dioxide and it also has a bent monomer anion. While gas-phase CO2 has negative EAg of —0.6 eV [24], for CS2, EAg is +0.8 eV [34]. Despite this very different electron affinity, Gee and Freeman [34] observed long-lived electrons in CS2 (with lifetime > 500 psec) with mobility ca. 8 times greater than that of solvent cations. Over time, these electrons converted to secondary anions whose mobility was within 30% of the cation mobility. Between 163 and 500 K, the two ion mobilities scaled linearly with the solvent viscosity, as would be expected for regular ions. Of course, Gee and Freeman s identification of the long-lived high-mobility solvent anions as electron is just a manner of speech Obviously, quasifree or solvated electrons cannot survive for over a millisecond in a positive-EAg liquid. 

The explanation for the two slopes in the plot lies in the fact that even a very pure crystal of NaCl contains some impurities, and the line corresponding to low temperatures (on the right of the plot) is due to the extrinsic vacancies. At low temperatures, the concentration of intrinsic vacancies is so small that it can be ignored because it is dominated by the defects created by the impurity. For a particular amount of impurity, the number of vacancies present will be essentially constant, jj in this extrinsic region thus depends only on the cation mobility due to these extrinsic defects, whose temperature dependence is given by Equation (5.9) ... 

The low frequency absorption II originates from the Maxwell-Wagner effect already observed in dehydrated X-type zeolites (8). In the presence of water the enhanced cationic mobility intensifies this effect. This interpretation disagrees with that of Matron et al. (10). They ascribed their low frequency a-process to cations on site I and site II. This is improbable in view of the correspondence with the Maxwell-Wagner effect in dehydrated X-type zeolites, observed by us (8). 

Equation (8.14) demonstrates once more that the cation flux caused by the oxygen potential gradient consists of two terms 1) the well known diffusional term, and 2) a drift term which is induced by the vacancy flux and weighted by the cation transference number. We note the equivalence of the formulations which led to Eqns. (8.2) and (8.14). Since vb = jv - Vm, we may express the drift term by the shift velocity vb of the crystal. Let us finally point out that this segregation and demixing effect is purely kinetic. Its magnitude depends on ft = bB/bA, the cation mobility ratio. It is in no way related to the thermodynamic stability (AC 0, AG go) of the component oxides AO and BO. This will become even clearer in the next section when we discuss the kinetic decomposition of stoichiometric compounds. 

A somewhat different situation is depicted in Figure 10-19. A flux of A+ cations is driven (e.g., by an electric field) across the boundary of the phase combination AX (a)/BX(jS). Since the AX side is anodic, the boundary shifts into BX. Two cases can be distinguished with respect to the cation mobilities 1) b%>b and 2) bXfirst case, the planar boundary is morphologically unstable since... 

The sorptive, catalytic, and ion-exchange properties of zeolites depend strongly on the kind, position, and mobility of the charge-balancing cations. Since chemical shifts and multiplicities of lines are related to site occupancy and their widths to cationic mobility, NMR can in principle provide important information on the nature of the intracrystalline environment. 

Consider an open capillary-type liquid junction. When it is filled with a non-equitransferrant electrolyte (i.e., one with different anion and cation mobilities) a diffusion potential develops that can be measured at the ends of the capillary. Does the value of the diffusion potential change when you change the length of the capillary Why ... 

Many materials have the properties of low conductance (high impedance) and low loss. These materials are often referred to as dielectrics. In addition, many materials not normally considered as dielectrics exhibit these properties. It is well known that dielectric methodologies are a good test for the study of molecular and cationic mobilities in materials [88,101-134],... 

Besides, the interaction of divalent cations with the zeolite framework and water is stronger on account of the higher charge and lower cationic radius exhibited by Ca2+ (Ca2+ 0.99 A) in contrast with Na+ and K+ (Na+ 0.95 A and K+ 1.33 A). This effect induces a lower mobility of divalent cations, on account of the fact that divalent cations are more intimately linked with the zeolite framework. Hence, the lower cationic mobility is an additional reason for the decrement in the permittivity of tested samples, and this effect is also detected by the thermodielectric analyzer as a decrease in V0 [110,119],... 

Anderson, J. M., Ineson, P. Huish, S. A. (1983). Nitrogen and cation mobilization by soil fauna feeding on leaf litter and soil organic matter from deciduous woodlands. Soil Biology and Biochemistry, 15, 463—7. 

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