## A Collision Theory-Based Derivation of Semiempirical Equations for Modeling Dispersive Kinetics and Their Application to a Mixed-Phase Crystal Decomposition

journal contribution

posted on 12.10.2006, 00:00 by Peter J. SkrdlaIn recent works, the author has shown the utility of new, semiempirical kinetic model equations for treating
dispersive chemical processes ranging from slow (minute/hour time scale) solid-state phase transformations
to ultrafast (femtosecond) reactions in the gas phase. These two fundamental models (one for homogeneous/deceleratory sigmoidal conversion kinetics and the other for heterogeneous/acceleratory sigmoidal kinetics;
isothermal conditions), based on the assumption of a “

*Maxwell**−**Boltzmann-like*” distribution of molecular activation energies, provide a novel,*quantum**-**based*interpretation of the kinetics. As an extension to previous work, it is shown here that the derivation of these dispersive kinetic equations is supported by classical collision theory (i.e., for gas-phase applications). Furthermore, the successful application of the approach to the kinetic modeling of the solid-state decomposition of a binary system, CO_{2}·C_{2}H_{2}, is demonstrated. Finally, the models derived appear to explain some of the (solid-state) kinetic data collected using isoconversional techniques such as those often reported in the thermal analysis literature.