Application of Grid-Based Molecular Methods for Modeling Solvent-Dependent Crystal Growth Morphology: Aspirin Crystallized from Aqueous Ethanolic Solution

A recently developed method (Hammond et al., 2006) for estimating solution binding at crystal habit surfaces and hence interfacial tension is extended to calculations of solution-effected attachment energies and hence to the prediction of solvent-mediated crystal morphology. The method is validated through examination of the morphology of aspirin crystallized from aqueous ethanolic solutions. The influence of supersaturation on the resultant crystal morphology is also discussed with reference to the differing intermolecular packing on this material's different crystal habit surfaces. The importance of preventing kinetic roughening via maintaining a facetted external growth morphology in terms of minimizing product purity is also highlighted.