(80f) Powder Electrostatics: Focus on Fundamentals Needed to Understand Applications

When two particles are colliding or sliding on each other, electric charges could be exchanged at the surfaces. This contact electrification called triboelectric effect is an old fundamental scientific subject. However, despite many studies dedicated to this subject, the fundamental mechanisms behind the triboelectric effect are not fully understood. In particular, the charging of objects composed by the same isolating material and charging of particulate materials are still a matter of theoretical investigations. From an experimental point of view, difficulties are also emerging when an electrostatic measurement is performed on a particulate system.

In this presentation, we will look at the state of the art on powder electrostatics and we will analyze the recent theoretical models. Afterward we will make the connection with experimental and numerical (DEM simulations adapted to implement tribocharging) studies. From an experimental perspective, we will focus on a measurement method (GranuCharge from GranuTools) able to measure the ability of a powder to electrostatically charge during a flow.