(128c) Contact Charging in Particulate Flows

Contact charging is a well-known phenomenon wherein material surfaces become asymmetrically charged following their contact and separation. In particulate flows, contact charging occurs through a combination of particle-particle and particle-wall interactions. For insulating materials, water is thought to play a central role, through the transport of water ions. This talk will first touch upon recent molecular dynamics simulations to characterize the thermodynamic driving forces for water ions to transfer from one surface to another [1]. It will then examine the effects of space charge and micro-discharges in the gas on the extent of particle charging [2-4]. It will then illustrate the interplay between gas-particle flows and charge accumulation on particles in fluidized beds.

[1] M.A. Webb, H. Zhang, and S. Sundaresan, “Can thermodynamics explain contact charging between insulating polymer surfaces?”, paper presented at the APS March Meeting 2023, Las Vegas, NV.

[2] X. Liu, J. Kolehmainen, I. Nwogbaga, A. Ozel, and S. Sundaresan, “Effect of particle size on tribocharging,” Powder Technol., 375, 199-209 (2020)

[3] X. Liu and S. Sundaresan, “The effect of gas on tribocharging of particles in a vibrated bed,” Powder Technol., 401, 117272 (2022).

[4] J. Hou, X. Liu, M. H. Rahaman, H. Li, S. Sundaresan, J. R. Grace, and X. Bi, ”Effect of gas properties and wall materials on particle charging in fluidized beds,” Can. J. Chem. Eng., 101, 244-255 (2023).