Relative chargeability of nanostructured and conventional particles by tribocharging

The relative chargeability of particles composed of aggregates of nanoparticles by tribocharging was measured and compared with that of conventional particles. Particles were dispersed through a Teflon® tribocharger into a 208m3 experimental chamber. The net charge-to-mass ratios of the dispersed particles were measured with a Faraday cup charge measuring device. Tribocharging with a Teflon® charger was able to charge the particles positively. NanoActive® TiO2 gained the greatest net charge-to-mass ratio (121mC/kg, s.d. = 007) followed by NanoActive® MgO (081mC/kg, s.d. = 012) and ISO fine test dust (066mC/kg, s.d. = 013). These net charge-to-mass ratios, however, were small compared to the Gaussian limit (<8%).Results suggest that commercially available tribochargers may not be suitable for imparting significant charge to nanostructured aggregates.