title: Visualization of hydration layers on muscovite mica in aqueous solution by frequency-modulation atomic force microscopy.
abstract: A three-dimensional interaction force mapping experiment was carried out on a muscovite mica surface in an aqueous solution using a high-resolution and low-thermal drift frequency-modulation atomic force microscope. By collecting oscillatory frequency shift versus distance curves at the mica∕solution interface, complicated hydration structures on the mica surface were visualized. Reconstructed two-dimensional frequency shift maps showed dot-like or honeycomb-like patterns at different tip-sample distances with a separation of 0.2 nm with each other, which agree well to the water molecule density maps predicted by a statistical-mechanical theory. Moreover, site-specific force versus distance curves showed a good agreement with theoretically calculated site-specific force curves by a molecular dynamics simulation. It is found that the first and second hydration layers give honeycomb-like and dot-like patterns in the two-dimensional frequency shift images, respectively, corresponding to the lateral distribution function in each layer.
authors.affiliation: Office of Society-Academia Collaboration for Innovation, Kyoto University, Kyoto 615-8520, Japan. keicoba@iic.kyoto-u.ac.jp
authors.forename: Kei
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Noriaki
authors.initials: N
authors.lastname: Oyabu
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kimura
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Ido
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Imai
authors.forename: Katsunori
authors.initials: K
authors.lastname: Tagami
authors.forename: Masaru
authors.initials: M
authors.lastname: Tsukada
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D012996:Solutions; D014867:Water; C011934:mica