Application of aerodynamic dispersion for evaluating charge transfer of the test materials due to collision will be addressed by the method reported in [1-4].  The main task here is to further develop the technique to measure the charge distribution of particles in the size range around 10 to 1000 µm using an external transverse electric field to modify particle trajectories from which the charge distribution can be evaluated.  The position and size of particles deposited at the base, as measured by Morphologi G3, will be used to infer by computation the particle charge magnitude and polarity. There is currently no commercial instrument for this purpose. A preliminary design concept of the new test rig is shown here. With advisory support from the industrial partner, Fluid Comp, PDRA5 will design a dispersion unit and receptacle equipped with electrodes for application of a transverse electric field.  The associated modelling work will be done in WP6, using the software packages described there, for trajectory calculation and its linkage with charge distribution. The industrial partner, Malvern Panalytical, will advise on the design of a unit for integration into Morphologi G3, which has already been provided on loan.

References:

1. Zarrebini, A., Ghadiri, M., Dyson, M., Kippax, P., & McNeil-Watson, F. (2013). Tribo-electrification of powders due to dispersion. Powder Technology, 250, 75–83.
2. Zafar, U., Alfano, F., & Ghadiri, M. (2018). Evaluation of a new dispersion technique for assessing triboelectric charging of powders. International Journal of Pharmaceutics, 543(1–2), 151–159.
3. Ali, M., & Ghadiri, M. (2017). Analysis of triboelectric charging of particles due to aerodynamic dispersion by a pulse of pressurised air jet. Advanced Powder Technology, 28(10), 2735–2740.
4. Alfano, F. O., di Renzo, A., di Maio, F. P., & Ghadiri, M. (2021). Computational analysis of triboelectrification due to aerodynamic powder dispersion. Powder Technology, 382, 491–504.