Electric Charge Coefficients

When NiCl2 is a majority salt and the Na+ ion is a minority ion, Fig. 28 indicates the critical potentials measured with changing NiCl2 concentration at constant Na+ ionic concentration 

In the same case as Fig. 28, as shown in Fig. 29, critical potentials have been measured as the Na+ ionic concentration is altered with constant NiCl2 concentration. Then the experimental result is 

Using these results, we can calculate the electric charge coefficients from Eqs. (50) to (53), 

Finally, with the data of Eq. (59a) to (59c), the following electric charge coefficient was obtained 

From this result, as discussed in the preceding section, the instability in this case belongs to the case where the coefficient is smaller than -1. Hence it is concluded that the instability takes place when ( 2) becomes negative 

---

Electrically assisted transdermal dmg deflvery, ie, electrotransport or iontophoresis, involves the three key transport processes of passive diffusion, electromigration, and electro osmosis. In passive diffusion, which plays a relatively small role in the transport of ionic compounds, the permeation rate of a compound is deterrnined by its diffusion coefficient and the concentration gradient. Electromigration is the transport of electrically charged ions in an electrical field, that is, the movement of anions and cations toward the anode and cathode, respectively. Electro osmosis is the volume flow of solvent through an electrically charged membrane or tissue in the presence of an appHed electrical field. As the solvent moves, it carries dissolved solutes. 

Let us first assume that we have a spherical particle with a radius of 5 p.m similar to an idealized toner particle, which is comprised of polystyrene, in contact with an electrically conducting substrate. A typical electric charge on a toner particle of that size is of the order of 10" " C. The Hamaker coefficient (Eq. 15) for such as system would be about 1.5 eV. 

In view of the electrostatic nature of forces that primarily lead to deviation of the behaviour of electrolyte solutions from the ideal, the activity coefficient of electrolytes must depend on the electric charge of all the ions present. G. N. Lewis, M. Randall and J. N. Br0nsted found experimentally that this dependence for dilute solutions is described quite adequately by the relationship... 

The plot of permeability coefficient versus molecular radius in Figure 10 shows the interdependence of molecular size and electric charge. The permeability of the solutes decreases with increasing size. The protonated amines permeate the pores faster than neutral solutes of comparable size, and the anions of weak acids permeate the pores at a slower rate. The transport behavior of the ionic permeants is consistent with a net negatively charged paracellular route. These results are phenomenologically identical to those found in the transport kinetics of... 

Porstendorfer, J. and T.T. Mercer, Influence of Electric Charge and Humidity upon the Diffusion Coefficient of Radon Decay Products, Health Phvs. 37 191-199 (1979). 

Notice that we have added the electron to B and B in order to account for the electrical charge on the aqueous species. This incorporation provides a convenient check the electron s reaction coefficient must work out to zero in order for the reaction to be charge balanced. 

I. 46. The magnitude of the coefficient reflects the electric charge distribution of the ionic species. A 0.1 molal solution of Al2(S04)3 has an activity coefficient of only 0.035. It should also be noted that, in dilute solutions, activity coefficients of electrolytes decrease in magnitude with increasing concentration. A minimum is reached and the coefficient then increases with concentration. See Activity Debye-Huckel Law Biomineralization... 

Recall from transition state theory that the rate of a reaction depends on kg (the catalytic rate constant at infinite dilution in the given solvent), the activity of the reactants, and the activity of the activated complex. If one or more of the reactants is a charged species, then the activity coefficient of any ion can be expressed in terms of the Debye-Htickel theory. The latter treats the behavior of dilute solutions of ions in terms of electrical charge, the distance of closest approach of another ion, ionic strength, absolute temperature, as well as other constants that are characteristic of each solvent. If any other factor alters the effect of ionic strength on reaction rates, then one must look beyond Debye-Hiickel theory for an appropriate treatment. 

ELASTICITY COEFFICIENT ELECTRIC CHARGE ELECTRIC POTENTIAL ELECTROMOTIVE EORCE ELECTROACTIVE SPECIES ELECTROCATALYSIS Electrocyclic reaction,... 

Fortunately, such complicated reactions usually involve oxidation and reduction, and the oxidation numbers of each element make it much easier to determine the coefficients for a balanced reaction. First, assign oxidation numbers to the elements in each substance. Examine only the elements that change their oxidation number, and insert coefficients so the number of electrons lost equals the number of electrons gained. Then modify any coefficients so the other elements that don t change oxidation number also balance. Finally, check that the electrical charges and the number of atoms of the elements are equal on both sides of the reaction. 

In such a material under these conditions, Fourier s law again pertains, but the thermal conductivity K depends on the direct coefficient Lqq, as in Eq. 2.25, as well as on the direct and coupling coefficients associated with electrical charge flow. In general, the empirical conductivity associated with a particular flux depends on the constraints applied to other possible fluxes. 

Most nonequilibrium systems are characterized by variation of velocity, temperature, composition, or electrical potential with position and the consequent transport of momentum, energy, mass, or electric charge. Naturally, transport of two or more of these may occur simultaneously. Attention is focused here, however, on situations where only one transport process occurs and a transport coefficient can be calculated from its measured rate. For example, thermal conductivity can be calculated if the rate of energy transport and the temperature variation in the system are measured. 

This means that the electric charge will be automatically and topologically discretized in a model in which these two forms—and 0 a—are proportional the fundamental charge is equal to the proportionality coefficient and the... 

Q q R i l, i 2 Rb Rd Rg RP Ro r rc S Electric charge (As), heat (J), quality factor of a resonator Heat per unit area (J m-2), integer coefficient Radius of a (usually) spherical object (m), gas constant Two principal radii of curvature (m) Radius of a spherical bubble (m) Radius of a spherical drop (m) Radius of gyration of a polymer (m) Radius of a spherical particle (m) Size of a polymer chain (m) Radius (m), radial coordinate in cylindrical or spherical coordinates Radius of a capillary (m) Entropy (J K-1), number of adsorption binding sites per unit area (mol m-2), spreading coefficient (Nm-1)... 

In a free solution, the electrophoretic mobility (i.e., peiec, the particle velocity per unit applied electric field) is a function of the net charge, the hydrodynamic drag on a molecule, and the properties of the solutions (viscosity present ions—their concentration and mobility). It can be expressed as the ratio of its electric charge Z (Z = q-e, with e the charge if an electron and q the valance) to its electrophoretic friction coefficient. Different predictive models have been demonstrated involving the size, flexibility, and permeability of the molecules or particles. Henry s theoretical model of pdcc for colloids (Henry, 1931) can be combined with the Debye-Hiickel theory predicting a linear relation between mobility and the charge Z ... 

Influence of electric charge and humidity upon the diffusion coefficient of radon decay products. Health Physics, 37,191-9. 

---