Unified theoretical framework for temperature regulation via phase transition.

Phase transition usually consumes or releases energy to produce cooling or heating within different materials, providing a generalized framework for temperature regulation in practical applications. Because of the strong coupling between the enthalpy change in thermodynamics and heat-mass transfer kinetics, unveiling the mechanism of temperature regulation via the phase transition remains a great challenge. Here, we develop a new theoretical method by establishing a connection of enthalpy change from thermodynamics to phase transition dynamics to study evaporation-induced cooling as an example. Our new approach can spontaneously generate evaporative cooling at interfaces, and the predicted results are consistent with recent experiments. The evaporation-induced steady vapor is dictated by an anomalous cold-to-hot mass transfer through temperature-dependent chemical potentials, which enables temperature regulation inside liquids via a thermodynamic-kinetic interplay. Moreover, we show that a simple prohibition of heat exchange between liquids and reservoir can greatly enhance the cooling magnitude by a factor of 2∼4, which is highly dependent on the thermodynamics and kinetic coefficients of liquids. Our new method paves the way for exploration of cooling or heating induced by different phase transitions, such as evaporation, sublimation, or condensation, in a unified framework, which can significantly promote the development of temperature regulation by phase transitions.