Molecular Dynamics Simulation of Water Confined in Carbon Nanotubes

Molecular dynamics simulations are performed for water confined in carbon nanotubes with various diameters (11.0--13.8AA). The simulations under an isobaric pressure (one atmosphere) by lowering temperatures from 300K to 190K are carried out. Water molecules within variously sized tubes tend to transform from disorder to order with different configurations (four-water-molecule ring, six-water-molecule ring and seven-water-molecule ring) at phase transition temperatures, which may be lowered by the increasing tube radius. It is also found that the configurations of water in (10, 10) tube are not unique (seven-molecule ring and seven-molecule ring plus water chain).