title: The ice-like water monolayer near the wall makes inner water shells diffuse faster inside a charged nanotube.
abstract: Using molecular dynamics simulations, we have investigated the impact of the ice-like water monolayer inside the tube and nearest to the tube wall on the diffusion properties of other inner water shells confined within a charged nanotube. We find that the axial diffusion coefficient of the first water monolayer near the wall monotonously decreases with the charge size on the nanotube, indicating a tighter control of the first monolayer from the larger sized charge. However, for the other water shells, the diffusion coefficients increase when the charge is larger than a critical value qc (~1.0 e). This unexpected phenomenon is attributed to the decreased number of hydrogen bonds between the first monolayer and other inner water shells caused by the very unique hydrogen-bond network patterns in the first ice-like monolayer, which makes it behave like a "hydrophobic water layer." Our findings may have implications for water treatment, non-fouling surfaces, catalysis engine, and biological sensor.
authors.affiliation: Department of Physics, Zhejiang Normal University, Jinhua 321004, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wang
authors.forename: Fengmin
authors.initials: F
authors.lastname: Wu
authors.forename: Mei
authors.initials: M
authors.lastname: Feng
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Li
authors.forename: Hangjun
authors.initials: H
authors.lastname: Lu
authors.forename: Ruhong
authors.initials: R
authors.lastname: Zhou
mesh_terms: D004058:Diffusion; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D043942:Nanotubes / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water