title: Phase transition of nanotube-confined water driven by electric field.
abstract: The effects of electric field on the phase behaviors of water encapsulated in a thick single-walled carbon nanotube (SWCNT) (diameter = 1.2 nm) have been studied by performing extensive molecular dynamics simulations at atmospheric pressure. We found that liquid water can freeze continuously into either pentagonal or helical solidlike ice nanotube in SWCNT, depending on the strengths of the external electric field applied along the tube axis. Remarkably, the helical one is new ice phase which was not observed previously in the same size of SWCNT in the absence of electric field. Furthermore, a discontinuous solid-solid phase transition is observed between pentagonal and helical ice nanotubes as the strengths of the external electric field changes. The mechanism of electric-field-induced phase transition is discussed. The dependence of ice structures on the chiralities of SWCNTs is also investigated. Finally, we present a phase diagram of confined water in the electric field-temperature plane.
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Department of Physics, Fudan University, Shanghai, People's Republic of China.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Fu
authors.forename: Yin
authors.initials: Y
authors.lastname: Luo
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Ma
authors.forename: Guanghong
authors.initials: G
authors.lastname: Wei
mesh_terms: D004560:Electricity; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D044367:Phase Transition; D014867:Water / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D014867:Water