What can a kinetic modelling approach reveal about the intricacies of mechanochemical kinetics?

Abstract

Mechanochemistry is emerging as a powerful and sustainable route to chemical compound's synthesis. Yet, many fundamental aspects of its reactivity remain poorly understood, limiting its wider adoption as a truly green technology. A key challenge lies in rationalising the kinetic behavior of mechanochemical reactions, owing to the inherently multiscale and heterogeneous nature of the process. In this work, we address this challenge by applying a well established phenomenological kinetic model to ball milling experimental data from a benchmark reaction: the base-catalysed disulfide exchange between two symmetric disulfide homodimers. This approach enables a quantitative comparison between ball mill neat grinding (NG) and ball mill liquid assisted grinding (LAG) conditions, as well as the effects of different seeding levels of the disulfide heterodimer, the reaction product, and its two polymorphs. Our results provide a coherent quantitative picture of the underlying mechanisms at play, revealing how variations in liquid content and seeding conditions influence the kinetic parameters that govern transformations.