Tribochemistry as an Alternative Synthesis Pathway

Abstract

While reactions driven by mechanical force or stress can be labeled mechanochemical, those specifically occurring at a sliding interface inherit the name tribochemical, which stems from the study of friction and wear: tribology. Increased perception of tribochemical reactions has been gained through technological advancement, and the development of new applications remains on-going. This surprising physico-kinetic process offers great potential in novel reaction pathways for synthesis techniques and nanoparticle interactions, and it could prove to be a powerful cross-disciplinary research area among chemists, engineers, and physicists. In this review article, a survey of the history and recent usage of tribochemical reaction pathways is presented, with a focus on forging new compounds and materials with this sustainable synthesis methodology. In addition, an overview of tribochemistry’s current utility as a synthesis pathway is given and compared to that of traditional mechanochemistry.

Computational Tribochemistry: A Review from Classical and Quantum Mechanics Studies

“…Thus, it has become an intensive topic of interest indicated by a rapid increase in the number of publications in the field "tribochemistry", especially from the 1990s (Figure 1). 2 Through the years, many analytical techniques such as scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS), have been utilized for surface characterization and tribofilm analyses. However, due to the complexity of reactions in contact regions, it is challenging to unveil the precise mechanism of these reactions under dynamical conditions.…”

“…Increment in the number of publications in the field of “tribochemistry” over the past 50 years. Reprinted with permission from ref . Copyright 2020 MDPI.…”

SpeedMixing: Rapid Tribochemical Synthesis and Discovery of Pharmaceutical Cocrystals without Milling or Grinding Media**

“…SpeedMixing cocrystallization operates without bulk solvents, using conditions typically found in liquid‐assisted mechanochemistry, but also without grinding or milling media. By relying only on rapid mixing in the absence of any grinding media, the SpeedMixing approach represents a unique [9] route to bulk synthesis based on tribochemical effects, i.e. by shear and rubbing of particles, without impact and crushing present in other mechanochemical techniques such as milling [10] .…”

Mechanochemical reactions of GaN-Al2O3 interface at the nanoasperity contact: Roles of crystallographic polarity and ambient humidity

“…The shear-induced formation of oxide and hydroxide layers on GaN surface with the aid of water molecules in high humidity conditions distinctly improved the removal rate by two orders of magnitude compared with that in dry air conditions, and the removal process was described as the mechanical abrasive removal of the continuously oxidized layer on GaN substrate. However, the mechanochemical removal and the stress corrosion-induced mechanical removal process are difficult to distinguish under the plastic yield contact situation [22,23]. Besides, the wurtzite GaN single crystal has a spontaneous polarization along the <0001> crystal orientation and exhibits two different polar faces with distinct polarization orientations, i.e., Ga-polar (0001) and N-polar (0001) crystal faces.…”