Nucleation And Phase Behaviors Of Inorganic Small Molecular Fluid In Confined Systems

Phase transition is an important research topic in condensed matter physics.The confined effect plays a crucial role in phase transition.The nucleation and phase behavior of carbon dioxide and water in confined system are investigated in this dissertation.We first use the classical density functional theory to study the drying transition and density fluctuation of carbon dioxide in cylindrical nanopore.It is found that the density fluctuations nearby the predrying line could exceed its bulk value by two orders of magnitude.The thickness of the layer with large density fluctuation is more than 3 nm to the wall.These behaviors are the combined effect of nanopore's solvophobicity and confinement.Then we study the ice nucleation on metal surfaces by molecular dynamic simulation.It is found that the hydrophobic surface could retard the ice nucleation.There are two types of nucleation process in simulation.A skeleton nanostructure could be observed in slow nucleation.The structure is comprised by pentagons with dodecahedrons as link points,and stabilizes the pentagons in ice.These results are useful for understand the nucleation and phase transition,and can be used to guide the relevant process in physical and industrial applications.