Molecular dynamics of ice-nanotube formation inside carbon nanotubes

TL;DR

This study uses molecular dynamics simulations to investigate the phase transition of water confined in carbon nanotubes, revealing how nanotube diameter influences the formation of ice-nanotubes and their transition temperatures.

Contribution

It provides detailed simulation data on ice-nanotube formation inside carbon nanotubes, highlighting the diameter dependence and energy contributions affecting the transition temperature.

Findings

Transition temperature peaks at nanotube diameter with 5 ring members.

Water-water interactions dominate the phase change energy.

Water-carbon interactions influence diameter dependence of transition temperature.

Abstract

The first order phase transition of a water cluster confined in a dynamic single-walled carbon nanotube is investigated using a classical molecular dynamics (MD) method. The formation of ice-nanotube is monitored through the structure factor and potential energies. The transition temperature and its diameter dependence obtained by the simulations agree well with those of previously reported experiments. The transition temperature of the ice-nanotube was shown to take a maximum value of around room temperature with the number of the ring members n=5. Potential energy contribution to the phase change is generally dominated by that of the intrinsic water-water interaction, while that of water-carbon interaction plays a significant role on determining the dependence of transition temperature on the nanotube diameter.