The effect of ball mass on the mechanochemical transformation of a single-component organic system: anhydrous caffeine.

ABSTRACT: Mechanochemical methodologies, particularly ball milling, have become commonplace in many laboratories. In the present work, we examine the effects of milling ball mass on the polymorphic conversion of anhydrous caffeine. By investigating a single-phase system, the rate-limiting step of particle-particle contact formation is eliminated. It is found that larger milling balls lead to considerably faster conversion rates. Modelling of the transformation rate suggests that a single, time-independent rate constant is insufficient to describe the transformation. Instead, a convolution of at least two rate-determining processes is required to correctly describe the transformation. This suggests that the early stages of the transformation are governed only by the number of particle-ball collisions

SUBMITTER: Michalchuk AAL 

PROVIDER: S-EPMC6434987 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature