Supercooling Suppression in Phase Change Slurries by Nucleation Agent Optimization with Molecular Dynamics Simulations

Phase Change Slurries (PCS/PCME) are an efficient medium for isothermal energy storage and transportation. In nanometer-sized dispersion droplets, supercooling decreases the available heat capacity in a specific temperature range. Since Phase Change Materials (PCM) are mostly used in applications with narrow operating temperature interval, supercooling can lead to a reduction of usable phase transition enthalpy or in the worst case to its entire unusability. Investigating the crystallization process at the molecular level with MD simulations and the OPLS force field, we aim for a better understanding of the PCM ordering process. It has shown several structural and chemical dependencies of the freezing point from all included materials, such as surfactant, nucleation agent and PCM itself. A model for the crystallization was developed which helps to understand supercooled rotation phases and allows for the transfer to other organic PCS. This enables the search for highly efficient nucleation starters for subsequent experimental verification.