The physics of phase transition phenomena enhanced by nanoparticles

Abstract

Phase transitions are fundamental phenomena in physics that have been extensively studied owing to their applications across diverse industrial sectors, including energy, power, healthcare, and the environment. An example of such applications in the energy sector is thermal energy storage using phase change materials. In such systems, and indeed in many other thermal systems, an emerging and promising approach involves the use of nanoparticles, which have been extensively studied for their potential to enhance the performance of thermal systems. However, conducting thermodynamic analyses of thermal systems in the presence of nanoparticles proves to be complex and resource-consuming because of the involvement of many parameters, including (i) temperature, molecular structure, and composition of the host fluid in which nanoparticles are either dispersed or in physical contact; (ii) nanoparticle morphology, size, type, and concentration; and (iii) complex interactions between the nanoparticles and the base fluid. This article reviews recent studies on the role of nanoparticles in phase transition processes such as freezing, melting, boiling, evaporation, and condensation. It begins with an overview of phase transition phenomena without nanoparticles, emphasizing the most important controlling parameters, and then examines the underlying physics of nanoparticle-involved phase transitions, critically examining their impact on process speed (transport rates). The article also explores physical phenomena, such as Brownian motion, thermophoresis, microconvection, and nanoparticle agglomeration, and considers their contribution to rate control (enhancement or reduction). Finally, the article presents challenges, research gaps, and suggestions for future exploration, aimed at offering a comprehensive understanding of the complex interplay between the presence of nanoparticles and the phase transition processes.