(78e) Rich Phase Behavior of Confined Water and Ice at the Nanoscale

Understanding phase behavior of highly confined water, ice, amorphous ice, and clathrate hydrates (or gas hydrates) not only enriches our view of phase transitions and structures of low-dimensional solids not seen in the bulk phases but also has important implications for diverse phenomena at the intersection between physical chemistry, chemical engineering and nanoscience. Classical molecular simulation (MD) is an indispensable tool to explore states and properties of highly confined water and ice. It also has the advantage in precisely monitoring the time and spatial domain in the sub-picosecond and sub-nanometer scales, which are difficult to control in laboratory experiments, and yet allows relatively long simulation at 10² nanosecond timescale that is impractical to first-principles molecular dynamics simulations. In this talk, I shall present an overview of MD simulation studies of the structures and phase behaviors of highly confined water, ice, amorphous ice, and clathrate in slit and cylinder nanopores. I will survey a variety of crystalline phases of low-dimensional ices and 2D ice clathrates revealed from MD simulations, as well as possible simulation evidence of 2D very-low-density, low-density, and high-density amorphous (2D VLDA, LDA HDA) ices.