Sugar alcohols are under investigation as phase change materials for long term heat storage applications. The thermal performance in such systems is strongly dominated by the nucleation and crystal growth kinetics, which is further linked to the crystal-melt interfacial free energy (surface tension), the latent heat, and the viscosity. We carry out a comprehensive study of sugar alcohols to examine their thermodynamic and kinetic properties, from both experiments and theoretical calculations. The theoretical study follows a bottom-up approach. A generalized AMBER force field obtained from first principle calculations is selected to construct the molecular models. Heat capacity, self-diffusion constant, viscosity, latent heat, and interfacial free energy of selected model materials are calculated through molecular dynamic simulations. In the experimental study, differential scanning calorimetry and viscosity measurements are performed. Also, the kinetics of the crystal growth is examined using a microscope. The experimental results are integrated with the Rozmanov model, and a strong dependence of growth speed on the degree of subcooling is identified. All the experimental measurements are compared with our theoretical work, and the results showed good agreement. The methodologies used in the calculation are proved effective and reliable for future prediction of unknown systems. In this study, the high viscosity and the high interfacial free energy are both found responsible for the sluggish kinetics of nucleation and crystal growth in sugar alcohols.
|Titel||Proceedings of the Advances in Thermal Energy Storage, EUROTHERM 99, 28-30 May 2014, Lleida, Spain|
|Status||Gepubliceerd - 2014|
|Evenement||Advances in Thermal Energy Storage (EUROTHERM Seminar 99), May 28-30, 2014, Lleida, Spain - Lleida, Spanje|
Duur: 28 mei 2014 → 30 mei 2014
|Congres||Advances in Thermal Energy Storage (EUROTHERM Seminar 99), May 28-30, 2014, Lleida, Spain|
|Periode||28/05/14 → 30/05/14|
|Ander||Advances in Thermal Energy Storage, EUROTHERM 99|