Hydrotalcites are an important class
of layered materials, displaying
ion-exchange, adsorption, and base catalytic properties. The crystallization
kinetics for hydrotalcites are however hardly available. Nevertheless,
as their reconstruction from the oxides (also called as “memory
effect”) is considered a synthesis route, this can be used
to study the crystallization phenomena. This note looks at the reconstruction
kinetics of a Mg–Al hydrotalcite using previously reported
kinetic expressions. It was found that high temperature is beneficial
if the process is controlled by nucleation. The temperature effect
is less obvious when the process reaches a diffusional control regime.
For example, temperature is beneficial to shorten the processing time
in a nucleation-regime conversion (e.g., 40%). However, to achieve
a high conversion (e.g., 98–99%), an intermediate temperature
shows the optimal condition, i.e., shortest processing time. The work
shows useful side effects of diffusional control. It also highlights
the importance of obtaining the kinetics over the entire range for
process optimization and, finally, emphasizes that both parameters
in the Avrami–Erofe’ev model impact the time required
to achieve a given conversion. Directions for further studies to understand
the kinetic-process relationships have been highlighted.
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