2. Analytical processing of kinetics according to solid morphology

When recording thermograms, one may ask how to relate the results obtained to the reaction taking place on an atomic scale: in other words, how does the macroscopic result observed in thermogravimetry provide access to the mechanism of the reaction itself? Conversely, what overall solid transformation kinetics does a given reaction mechanism, governed by a given limiting step, lead to? Theoretical work has long been devoted to this question. In many cases, the proposed models are now well recognized in terms of the relationship between the morphology of the initial solid (plates, powders, wires, etc.) and the shape of the thermograms. However, the effect of other parameters is still the subject of active research: the kinetic consequences of mechanical stresses that may originate in the product formed or at the reactant/product interface, the influence of the porosity of the layer formed......