The Greek philosopher and mathematician, Thales of Miletus observed, in around 600 BC, that by rubbing amber with wool, the amber could be made to attract small items like leaves or dust. This is known as the triboelectric effect.
In 1757, the Swedish physicist, Johan Carl Wilcke, published the first Triboelectric Series: a list that ranks materials according to their tendency to gain or lose electrons and therefore how quickly a material develops a charge relative to other materials on the list.
This list is not exhaustive but serves to illustrate that many industrial plastics will develop a charge easily and that this charge is of a negative polarity.
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