Redistribution of Charges

The charging process of a conducting spherical particle on contact with a flat electrode is described in ref [98]. In this work, the charge acquired by the particle was determined, and the force of particle interaction with the flat electrode was calculated. 

Particles can acquire a charge not necessarily as a result of contact with each other, but also as a result of an electric discharge in the clearance between them. In this case, it is necessary to know the electric field strength in the clearance. 

The natural condition of particles in direct contact is equality of the potentials of their surfaces. If the charge is acquired as a result of a breakdown, this condition is not always obeyed. 

the process of charge redistribution between particles should begin even before their contact, as a result of significant growth of the strength of the electric field in the clearance between them (see Section 12.2). However, because of incomplete equalization of the potentials of the particles and the presence of molecular forces of interaction, it can proceed unnoticed. In coarsely disperse systems, in which the size of particles, R, is around 1-200 pm, the process of charge redistribution can be the main barrier to integration of the dispersed phase. Thus, in 

Consider the process of redistribution of charges between two conducting spherical particles of radii Ri and R2 upon their collision in a uniform external electric field of strength Eq. The charges on the particles before collision are specified and are equal to and g - Note that upon redistribution of the charges the total charge on the particles Q maintained. The problem of defini- 

---

When two conducting phases come into contact with each other, a redistribution of charge occurs as a result of any electron energy level difference between the phases. If the two phases are metals, electrons flow from one metal to the other until the electron levels equiUbrate. When an electrode, ie, electronic conductor, is immersed in an electrolyte, ie, ionic conductor, an electrical double layer forms at the electrode—solution interface resulting from the unequal tendency for distribution of electrical charges in the two phases. Because overall electrical neutrality must be maintained, this separation of charge between the electrode and solution gives rise to a potential difference between the two phases, equal to that needed to ensure equiUbrium. 

The relatively large p shows that the reaction is very sensitive to substituent effects and implies that there is a relatively large redistribution of charge in the transition state. 

At any interface between two different phases there will be a redistribution of charge in each phase at the interface with a consequent loss of its electroneutrality, although the interface as a whole remains electrically neutral. (Bockris considers an interface to be sharp and definite to within an atomic layer, whereas an interphase is less sharply defined and may extend from at least two molecular diameters to tens of thousands of nanometres the interphase may be regarded as the region between the two phases in which the properties have not yet reached those of the bulk of either phase .) In the simplest case the interface between a metal and a solution could be visualised as a line of excess electrons at the surface of the metal and an equal number of positive charges in the solution that are in contact with the metal (Fig. 20.2). Thus although each phase has an excess charge the interface as a whole is electrically neutral. 

The redistribution of charges leading to Eq. (1) involves both free charges and dipolar layers. Therefore can be split into two... 

This idea has been developed by Burton and Ingold,7 but not upon a very satisfactory theoretical basis. From their work it is not clear why the postulated redistribution of charge should occur after, but not before, dissociation,... 

In such complex system as aluminosilicate precursor gels, various lifetime components can appear reflecting material structure. The gel structure is a result of direct interaction of cations with silicate, aluminate and aluminosilicate anions, redistribution of charges and electron density over the system of aluminosiloxane bonds with effect on the formation of different structural units [24],... 

It is of interest in this connection that Steam,26 in a discussion of enzyme kinetics from the point of view of statistical mechanics and quantum mechanics, regards interaction between a dipole (as part of the enzyme protein) and the reacting groups of the substrate, e.g., C—0, resulting in a redistribution of charge within the C—0 bond, as a more rational mechanism of activation than the loosening of the bond by distortion. 

The bonding of ions to metals is dominated by Coulomb attraction since there is a significant difference in electron affinity between the metals and ions. The bonding also involves a redistribution of charge through intermolecular charge transfer (between adsorbed ions and the surface) and intramolecular polarization (in ions and on the surface), which reduces the Pauli repulsion. 

The first term is the potential caused by the spherically distributed charge Q, the second term is the potential caused by redistribution of charge Q in response to the nonhomogeneous field of point charges —Q/n, and the third is the ordinary coulombic potential caused by the charges —Q/n. The potential Vl(r,0,[Pg.205]

The redistribution of charge occurs in the precursor or encounter complex [A B] with a first-order rate constant kx (Equation 6.105). 

Reactions that involve O2 as the reactant or the product may occur by an inner- or outer-sphere pathway when the redox partner is a transition metal. The same is true of reactions that consume or produce (V-. The inner-sphere reaction is defined by the presence of a bond to 02 in the transition state. Different types of inner-sphere reactions are possible including those that form covalent intermediates and those that do not. The outer-sphere reaction simply converts O2 to C>2, or vice versa, in the absence of covalent bonding. The free energy barrier in the reaction is expected to arise from the reorganization needed to accommodate electron transfer and the redistribution of charge. An additional contribution derives from lengthening or contracting the 0—0 bond. 

In the case of wide band gap insulators the current will be low at all voltages but will initially exceed that to be expected under equilibrium conditions because of a redistribution of charges in the vicinity of the junctions. This makes it... 

---