Investigating the role of thermal interactions during freezing on the morphology of freeze-dried products

The solidification of water into ice is initiated by a stochastic phenomenon called nucleation. Since the phase change is an exothermic process, the heat released by nucleation in a vial can delay nucleation in the neighbouring ones. The combination of these two phenomena causes each vial to have a unique thermal profile. Since the ice crystal size depends on the thermal history of the solution, the morphology of the final product results to be heterogeneous. In this work, experiments were coupled to a mathematical model to assess the influence of thermal interactions during freezing on the morphology of freeze-dried products.