Bulk material electric charge

In this equation, the second term describes purely electrostatic work, connected with an infinitely slow transfer of charge zF from infinity in a vacuum into the bulk of the second phase, i.e. to a point with electric potential 0. Here only electric charge is transferred, not a material species with which it might be connected. The ratio of this work to the transferred charge is equal to the inner electrical potential 0 of the given phase. 

Polyurethanes with antistatic properties are suitable for use where static electrical charges must be dissipated. The polyurethane must be compounded to provide the antistatic properties throughout the whole bulk of the material. The antistatic agent, if a liquid, must not migrate to the surface readily. Surface coating the item is not desirable, as the effect is only temporary. 

The astute reader may argue at this point that since the bulk of any material has to be neutral, it follows that f was constant across that material and therefore the electric work was a constant that could be included in p.°, for instance. The fundamental problem with this approach, however, is that in order to insert a charged particle into a given phase, an interface has to be crossed. It follows that if a given interface is charged with respect to the bulk, the electric work can no longer be neglected. 

Electrical charges generated by static electrization scatter not only over the surface but across the material bulk as well. The direct consequence of friction-induced electrization process in polymers is the emergence of the electret state. 

The surface of the material may become charged (for example, by contact with a different material). The charge is evident from the associated external electric field and may give rise to hazardous discharges. The charge decays by conduction through the surface or bulk of the material. 

SnO containing films the bulk materials and cast-side surfaces were characterized as dielectric in nature with loss and conduction. The air-side charging characteristics, on the other hand, were markedly different from the volume mode charging characteristics. No short term polarization occurred in the samples implying little or no direct contribution from the polymer matrix to the air-side electrical properties. Also, the air-side electrical resistivity of BTDA-ODA polyimide films at room temperature was reduced substantially for both cobalt chloride modified and tin chloride dihydrate modified samples (i.e. six orders of magnitude and eleven orders of magnitude, respectively). 

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