title: Between scylla and charybdis: hydrophobic graphene-guided water diffusion on hydrophilic substrates.
abstract: The structure of water confined in nanometer-sized cavities is important because, at this scale, a large fraction of hydrogen bonds can be perturbed by interaction with the confining walls. Unusual fluidity properties can thus be expected in the narrow pores, leading to new phenomena like the enhanced fluidity reported in carbon nanotubes. Crystalline mica and amorphous silicon dioxide are hydrophilic substrates that strongly adsorb water. Graphene, on the other hand, interacts weakly with water. This presents the question as to what determines the structure and diffusivity of water when intercalated between hydrophilic substrates and hydrophobic graphene. Using atomic force microscopy, we have found that while the hydrophilic substrates determine the structure of water near its surface, graphene guides its diffusion, favouring growth of intercalated water domains along the C-C bond zigzag direction. Molecular dynamics and density functional calculations are provided to help understand the highly anisotropic water stripe patterns observed.
authors.affiliation: Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Jin Sik
authors.initials: JS
authors.lastname: Choi
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Lee
authors.forename: Bae Ho
authors.initials: BH
authors.lastname: Park
authors.forename: Danil
authors.initials: D
authors.lastname: Bukhvalov
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Son
authors.forename: Duhee
authors.initials: D
authors.lastname: Yoon
authors.forename: Hyeonsik
authors.initials: H
authors.lastname: Cheong
authors.forename: Jun-Nyeong
authors.initials: JN
authors.lastname: Yun
authors.forename: Yousung
authors.initials: Y
authors.lastname: Jung
authors.forename: Jeong Young
authors.initials: JY
authors.lastname: Park
authors.forename: Miquel
authors.initials: M
authors.lastname: Salmeron
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D004058:Diffusion; D006108:Graphite / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D012822:Silicon Dioxide / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D014867:Water; D012822:Silicon Dioxide; D006108:Graphite; C011934:mica
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