Polarization induced bound surface charge

The key factor in most biological processes is the need for a small change of the pH concentration created by the release of H ions during biochemical reactions. Therefore, determination of pH is a prerequisite for many processes. The sensing mechanism for pH is the polarization-induced bound surface charge by interaction with the polar molecules in the liquids. Application of ZnO nanorods as pH sensors... 

There is a certain correlation between the polarization and the surface-bounded charges density. To establish this, we must imagine that we have cut in a flat dielectric plate an elementary volume (e.g., in the form of a cylindrical rod) along the field force lines perpendicular to the dielectric s surfaces (Figure 4.22). Assume the face area to be AS, the cylinder length I and the bounded charges density a . Therefore Aq=ASa and the induced electric dipole moment p = Aql = a ASl. Then the polarization of the allocated dielectric rod shall be found relating the electric moment p of the rod to its volume AV, i.e., = p/AV. 

On the macroscopic scale we have earlier defined the polarization, P, to represent the bound charges induced per unit area on the surface of the material. Therefore, if we take unit areas on opposite faces of a cube separated by a distance d, the dipole moment due to unit area will be... 

H-O bond contraction. Coulomb repulsion, and dual-process polarization drive the supersolidity with multiple features. The molecular separation doo = d + dn grows and molecular size d shrinks simultaneously at the skins because of the molecular under-coordination [21]. The H-0 bond contraction follows the rule of BOLS correlation the doo expansion results from the Coulomb repulsion between electron pairs on adjacent oxygen atoms [21, 24]. The polarization of water molecules in the molecular clusters [25, 26], surface skins, or ultrathin films of water is related to the molecule volume expansion because of the molecular charge conservation. The undercoordination-induced polarization lowers the work function of the bound electrons [6]. 

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