Triboelectric charging of a glass bead impacting against polymers: Antistatic effects in glass/PU electrification in a humidity-controlled environment

Abstract

A single impact triboelectric charging experimental setup has been used to investigate the antistatic effect of two additives coated at the surface of beads on impact charges resulting from impact between a glass bead and a polyurethane (PU) target, at various additive concentrations and two different RH conditions. Three configurations of additives have been studied exhibiting different behaviours with RH, underlining the importance of humidity conditions in antistatic properties. Results for additive A, an organic oil, showed almost no impact charge decrease at RH 1% while results for additive B, a quaternary ammonium salt, presented no difference between RH 1% and 45%. This behaviour could be explained by a difference in surface water desorption dynamic when placed in a low humidity environment. In a second part, additional measurements analysing the effect of RH and temperature in the same glass/PU impact configuration in absence of additives are discussed. No significant variation of impact charge was observed on glass/PU triboelectric charging, confirming that previous results were indeed related to the presence of additives at the surface of the beads. A comparison with another triboelectric pairing, glass/PTFE, also shows the likeliness of different charge transfer mechanisms being involved in glass/PU and glass/PTFE as well as a general effect of temperature on impact charge which could be connected to relaxation mechanisms.