Thermodynamic and Other Effects of Electric Fields

The thermodynamic effects of electric fields exist and are well known. The application of an electric field to a solution can induce an effect on chemical equilibrium. For example, the equilibrium of Eq. (18) where C has a large dipolar moment while B has a small dipole is shifted toward C under the action of an electric field  

Typical examples are the conversion of the neutral form of an amino acid into its zwitterionic form, the helix-coil transitions in polypeptides and polynucleotides, or other conformational changes in biopolymers. Reactions of higher molecularity where reactants and products have different dipole moments are subject to the same effect (association of carboxylic acids to form hydrogen-bonded dimers). Equilibrium involving ions are often more sensitive to the application of an electric field the field induces a shift toward producing more ions. This is known as the dissociation field effect (DFE) or the second Wien s effect [134], 

In principle the effect of an electric field on chemical equilibria can be described by the thermodynamic relationship described by Eq. (71)  

if thermodynamic effects of an electric effect exist, the electric field strengths necessary are too high compared with the ordinary operating conditions of microwave heating. 

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