Electrical tribocharging is a fundamental physicochemical phenomenon and the basis of electrophotographic development. Despite extensive study, a complete understanding of the mechanism–commonly referred to as electron or ion transfer–remains unclear. Using a quantum chemical (QCh) approach, we studied the electron charge transfer (ECT) as one possible atomic-scale mechanism of tribocharging. We also describe ECT for several systems based on two materials in contact (tribopairs). Methods of density function theory and time-dependent density function theory were applied to QCh modeling using a cluster approach. A series of energetic and charge characteristics at the atomic level were calculated: including the highest- and lowest-occupied molecular orbitals (respectively) and the Fermi levels of complex components in their individual (free) as well as contact states, before and after electron excitation, ECT-excited energy states, charge distribution in the complexes, and the dipole moments of the excited complexes with ECT. Correlations were evaluated between the transferred charges and dipole moments and between transferred charges and Fermi levels. Furthermore, we could show that the QCh analysis offers insight into the ranking of tribocharging agents based on their chemical nature.
Ekaterina Nikitina, Herbert Barthel, Mario Heinemann, "Electron Transfer in Electrical Tribocharging Using a Quantum Chemical Approach" in Journal of Imaging Science and Technology, 2009, pp 40503-1 - 40503-9, https://doi.org/10.2352/J.ImagingSci.Technol.2009.53.4.040503