Relative Chargeability of Nanostructured and Conventional Particles by Tribocharging

Abstract

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 20.8 m³ 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 (1.21 mC/kg, s.d. = 0.07) followed by NanoActive® MgO (0.81 mC/kg, s.d. = 0.12) and ISO fine test dust (0.66 mC/kg, s.d. = 0.13). 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.

Keywords:

• chargeability
• charge-to-mass ratio
• Faraday cup sampler
• nanostructured particles
• tribocharging

Acknowledgments

This work was funded by the United States Marine Corps Systems Command through M2 Technologies, Inc. and Kansas Agricultural Experiment Station. The technical assistance provided by Darell Oard, Edna Razote, Emad Almuhanna, and Tyler Pjesky is acknowledged.

Notes

^a Source: Measured using Aerodynamic Particle Sizer® (APS).

^b Source: Thermoclad Co., Erie, PA.

^c Source: Measured using multipycnometer.

^d Source: Nanoscale Corp., Manhatan, KS.

^a Average of three replicates.