Role of Phonon-Phonon Coupling and Binding in Determining Heterogeneous Nucleation and Interfacial Thermal Transport.

Understanding the mechanisms behind heterogeneous nucleation and thermal transport across the solid-liquid interface is essential to industrial applications, such as energy conversion and high-density thermal management. Since the evaporative mass transfer from microlayer occurs in extremely small length and time scales, questions regarding liquid-vapor phase changes are seemingly unresolved yet. In this study, the aim is to determine the underlying impacts of interfacial thermal transport on bubble nucleation and the boiling heat transfer performance. Herein, molecular dynamics simulations of an argon-copper system coupled with a mechanical pressure control method is performed to elucidate vibrational coupling and binding effects. This can be achieved by varying the atomic mass of the solid phase and the interatomic interaction between solid and liquid phases. In this way, interfacial thermal conduction mechanisms are identified through spectral analysis. Results found that increasing the spectral overlap and the interatomic interaction in interfacial layers can shorten the onset time of nucleation and strengthen the boiling heat transfer efficiency. Even for nonhydrophilic surfaces, a proper interfacial vibration coupling can compensate for the heat transfer deterioration and exhibit boiling characteristics comparable to hydrophilic surfaces. In addition, an interfacial vibration factor that combines the vibrational coupling and binding effects is proposed to provide a prediction of bubble nucleation and boiling performance. These findings can provide valuable insights into nucleation regulation strategies and boiling-based applications.