Regensburg 2022 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster 2

CPP 17.11: Poster

Tuesday, September 6, 2022, 11:00–13:00, P2

Physics of supersaturated, agitated sucrose solutions: Crystal nucleation and growth — •Hannah M. Hartge and Thomas A. Vilgis — Max Planck Institute for Polymer Research, Mainz, Germany

Supersaturated sucrose solutions that have been sufficiently cooled without nucleation constitute a meta-stable system in which agitation promotes fast crystallization. Applications of this physically interesting process can be found for example in the production of fondant in confectionery. While just water and sucrose are present, the system goes through complex thermodynamic processes during crystallization, which are highly dependent on composition, temperature, and agitation.

In this work, we investigate how temperature and concentration affect nucleation, crystal growth and final particle size distribution of highly supersaturated sucrose solutions under agitation. To do so, the torque was measured during kneading of the samples at controlled temperature, followed by light microscopy and corresponding image analysis. When crystallization times were compared to classical nucleation theory, variations were found to be related to temperature and supersaturation in the same way as indicated by induction time models of statistical physics. Additionally, size distributions of the resulting crystal phases showed a strong dependence on temperature during agitation, sucrose content and according initial supersaturation.