Fractal Reaction in Solids: Reaction Functions Reconsidered

Based on the fractal nature of pulverized solid particles described in previous reports by the authors, the reaction mechanism which defines the reaction rate of a heterogeneous system is reconsidered. The 9 functions given in a commonly used classification by Sharp et al. are shown collectively in 3 functions. The introduction of diffusion in a non-integer dimension results in functions deviating from the known ones, particularly in a diffusion-controlled reaction. Though the models referred here are too simple to be directly applied to a system consisting of many particles, this paper shows that it is meaningless to discuss a particular reaction by fitting it to a classical 1-, 2-, and 3-dimensional reaction mechanism.