Advances in Tribochemistry

Mechanochemical reactions are ubiquitous, but often go unnoticed or are considered atypical. One example of mechanochemistry is a chemical reaction that occurs at the sliding interface of two solid materials, often called tribochemical reactions. Another example is the synthesis of organic chemicals through the collision of solid particles, for example in ball milling processes. Mechanochemical reactions are quite different from chemical reactions that occur through heating, photon irradiation, or electrical bias. In contrast to these chemical reactions, for which the transition or flow of electrons between electronic states leads to changes in the atomic positions of molecules involved in the reactions, a mechanistic understanding of mechanochemically-activated reactions, in which a mechanical force alters reaction energies and pathways, has not yet been well established.

Mechanochemical reactions rely on factors such as mechanical interaction, temperature, physical and chemical properties of solid surfaces, and even environmental factors such as additives or gas molecules. Therefore, it is extremely challenging to elucidate the potential reaction pathway due to the very large number of degrees of freedom and complexity of reaction conditions involved in buried interfaces. Central questions include: how are mechanical stresses transferred to molecules from external solid surfaces, displacing the molecular conformation from equilibrium states or positions; and how to control reaction pathway or gates that can suppress unwanted reactions, or facilitate wanted reactions. Recent technological advances such as the atomic force microscope, transmission electron microscope, and other microscopic approaches offer promising alternatives to studying these issues. This experimental approach needs to be complemented by numerical simulations such as reactive molecular dynamic (MD) simulations and density functional theory (DFT) calculations.

We welcome reviews and original research articles that address, but are not limited to, the following themes:
• Tribochemical reactions at sliding interfaces with additives and related applications
• Theory, modeling, and experiments of tribochemical wear
• Modeling and simulations of mechanochemical reactions based on MD and DFT simulations
• Superlubricity due to mechanochemical reactions
• Novel multiscale computational approaches for studying mechanochemical reactions
• Novel experimental approaches such as high resolution and surface enhanced spectroscopies