Combined isochoric processes of freezing and supercooling.

This study presents a thermodynamic analysis and design strategy for a multiphase isochoric system that enables supercooled preservation of matter at lower temperatures without increasing the probability of ice nucleation. In isochoric supercooling, ice nucleation events follow a Poisson distribution and depend on the temperature differential between the equilibrium phase transition temperature and the preservation temperature. The proposed technology employs a multiphase isochoric system in which matter, suspended in an isotonic solution, is enclosed within a compartment bounded by a membrane that permits heat and pressure exchange but prevents mass transfer. The remaining chamber volume is filled with water. Preservation begins by cooling the system until the water phase fully freezes, inducing a pressure rise. The biological compartment is then supercooled relative to the new equilibrium pressure and temperature established by the frozen water. This capability enables the design of elevated-pressure conditions that reduce microbial contamination without compromising quality.