Tribo electric effects

Another process, associated with flow, is the tribo-electric effect in which electrons are transferred from one molecule to another during flow. This requires contact between donor and acceptor molecules or ions which are then forced apart and retain their charges. As stressed above, these centres are likely to be paramagnetic and should be detected by ESR spectroscopy. This phenomenon is very well established at the electrostatic level for surface charges, but is sometimes hard to distinguish from bond homolysis in several systems (Symons,... 

This latter reaction would rmih in an increase in ESR intensity and hence would explain the anomalous decay. Son doubt exists whether this proposed mechanism can explain the anomalous decay experienced in tensile tested samples. Firstly the friction effects to produce the tribo-electricity charge are not so clearly present. Secondly, Mead et al have dtown that the peroxy radical content decreases as... 

A type of angle-dependent x-ray photoemission spectroscopy was used to investigate the molecular orientation at the surface of sulfonated polystyrene as a function of reaction depth. A model based on these measurements indicates that at a critical sulfonation depth the aliphatic hydrocarbon backbone becomes exposed preferentially at the surface. These results are consistent with surface energy and tribo-electric charging measurements, which also reveal the effects of associative interactions in the form of conversion dependencies. 

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