Continuum model for mesh crystallization

Abstract

The front propagation of a single crystallizing domain has been well studied for more than a century. In many important crystallization processes, however, multiple domains grow simultaneously, resulting in a multicrystalline, meshlike aggregate. This is the typical case for organic compounds, including polymers and alkanes. We have studied such growth in the case of a normal alkane precipitating from solution in the presence of kinetic inhibitors--additives which, when present in trace amounts, have a dramatic effect on growth kinetics and morphology. In this case, we observe a distinct banded growth with a typical length scale of 300 microm superimposed on the finer mesh structure. We present a simple continuum model that demonstrates the essential behavior of this growth.