Triboelectricity and friction. —V. On surface strain and relaxation of like solids

Abstract

It has been shown that the position of a solid, in the triboelectric series, depends on the previous treatment of its surface: thus, ebonite when rubbed by hard solids is lowered in the series; on heating it is raised again. This reversible process holds good, it was shown, for a great number of metals and non-metals. Later it was demonstrated† that charges arise when two identical surfaces of, say, clean annealed ebonite are rubbed together. Each surface becomes charged and, as rubbing continues, the charges change in amount, and even in sign, in a systematic way. The effects were attributed to progressive strain on the surface, brought about by pressure and friction. In the present paper we endeavour to standardise these effects by measuring the charges arising between known areas, pressed together by known forces, at stated temperatures.