Computational Tribochemistry: A Review from Classical and Quantum Mechanics Studies

Abstract

Recent years have witnessed the acceleration of research on tribochemical reactions in the tribology area. Together with new experimental findings, atomic modeling has increasingly contributed to the understanding of mechanistic insights and interpretation of tribochemical reactions and related frictional outcomes. Apart from showing agreement with experiments, efforts have been paid to develop simulation codes and models to bring simulations closer to practical tribotests with a reasonable computational expense. By simulations and modeling, tribochemical reactions and physical/chemical interactions between lubricants, surface−lubricant, contacting interfaces, and surface/ lubricant−environmental agents have been investigated. This work provides an up-to-date review of studies on physical/chemical interactions and tribochemical reactions in tribosystems using atomic computational simulations such as reactive force fields, quantum mechanics, and quantum mechanics/molecular dynamics. On the basis of the current development, we outline future prospects for the simulation and modeling section in the field of tribochemistry.

Insights into modeling approaches for boundary- and mixed-lubricated conditions

“…Cross-correlating experimental findings from tribo-testing and post-characterization with MD simulation results is crucial. This not only validates numerical outcomes but also provides fundamental bases and explanations for the intricate processes within the tribological interface (Martini and Kim, 2021;Ta et al, 2021;Onodera et al, 2010;He et al, 2023;Srivastava et al, 2021b).…”

Ab initio insights into the interaction mechanisms between H2, H2O, and O2 molecules with diamond surfaces

“…The presence of reactive dangling bonds on the clean DLC surfaces could significantly increase adhesion and friction. Still, those dangling bonds can be saturated by hydrogen and hydroxyl groups dissociated from water or hydrogen molecules [17,19,36,37,63]. The present results indicate that once formed, the C-H bonds are expected to resist subsequent dissociation due to, e.g., the wear-off caused by rubbing against a countersurface, more efficiently than the C-OH bonds.…”

Electrotunable friction with ionic liquid lubricants

“…MS methods can also be extended to include chemical reactivity between the lubricant and the confining surface and tackle tribochemistry problems and corrosion, which have become increasingly popular in the last years. Such simulations rely on quantum approaches to model formation and breaking of chemical bonds (Density Functional Theory, Quantum Mechanics/Molecular Mechanics, Reactive Force-fields) 76 . They complement surface chemistry techniques such as Scanning Electron Microscopy, STEM, or XPS 70 by providing a microscopic view of tribofilms 'in situ'.…”