Some phase change materials (PCM) can remain liquid at temperatures well below their melting point due to slow crystallization kinetics. In most PCM applications this is an unwanted effect that is moderated by the addition of nucleating agents or other types of nucleation-inducing techniques. However, there are also some cases where supercooling can be a desired property. If a stable supercooling and controlled activation/nucleation can be achieved, the PCM can act as a heat source that can be activated on demand (e.g. hand warmers). If the PCM can be additionally micro-encapsulated, in can be also incorporated in liquid mixtures or used in the form of a powder, opening the possibilities for a wide range of new applications.
In this project we explore the feasibility of stable supercooling and controlled nucleation of micro-encapsulated sodium acetate trihydrate (SAT) for the first time in literature.