Electron Transfer in Electrical Tribocharging Using a Quantum Chemical Approach

Abstract

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 transferremains unclear. Using a quantum chemical (QCh) approach, we studied the electron charge transfer (ECT) as one possible atomicscale 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.

Prediction of the Effective Work Function of Aspirin and Paracetamol Crystals by Density Functional Theory─A First-Principles Study

“…37,38 In recent years it has also been used to model triboelectric charging. Nikitina et al 39 applied time-dependent DFT to produce an ab initio predicted triboelectric series. It has also been used to study how material deformation and mechanically induced ionization at a surface might impact charge transfer.…”

“…Density Functional Theory (DFT) is a computational quantum mechanical modeling method that is widely used to study the electronic structure and properties of materials. , In recent years it has also been used to model triboelectric charging. Nikitina et al applied time-dependent DFT to produce an ab initio predicted triboelectric series. It has also been used to study how material deformation and mechanically induced ionization at a surface might impact charge transfer. − The work of Lin and Shao investigated how the presence of surface water can impact the electronic structure of a material, leading to a reversal in the polarity of transferred charges.…”