Frictional charging

Emission of light accompanying the rubbing or crushing of certain crystals and arising from frictional charge separation at the crystal surfaces. Also called piezoluminescence. 

D. Piezoluminescence Emission from frictional charges separation at the crystal... 

There are many other electrical phenomena associated with ice, such as frictional charging, which we do not have space to consider and others, such as Hall effect and the possibility of a ferroelectric transition, which must be mentioned only briefly. In the following sections we shall discuss in more detail the main features of the electrical behaviour outlined above. 

Desruisseaux, C., Long, D., Drouin, G, and Slater, G. W. Electrophoresis of composite molecular objects. 1. Relation between friction, charge, and ionic strength in free solution. Macromolecules 34, 44-52(2001). 

Japanese workers had independently reached similar qualitative conclusions based on limited series of oligomeric polystyrene derivatives. They utilized the related measurement technique of mercury contact charging. Later work using a complex frictional charging apparatus in vacuo confirmed our results as shown in Figure 5, a plot of their reported contact potential difference between a metal reference electrode and the films versus Hammett constant. Note the plateau effect at High potential differences. 

Kakiuchi [343] improved the induction method by avoiding the frictional charges due to surface contact. He made an apparatus with tte upper electrode fixed and the lower electrode, with the sample, movable. 

Subject matters to be discussed are the driving force for contact electrification, the charge carriers and the resultant charged states, the possibility that adsorption is involved in charge transfer and frictional charging. 

One other possible interference remains The cable noise. This effect can arise if movement of the shielded electrode cable causes the shielding network to rub against the polyethylene or teflon insulation, producing frictional charges. The so-called low noise cables can help to alleviate this problem. These contain a polyethylene insulation (to avoid the piezoelectric effect of teflon) which is coated with a layer of graphite powder or conducting synthetic resin. 

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