title: The microscopic structure of adsorbed water on hydrophobic surfaces under ambient conditions.
abstract: The interaction of water vapor with hydrophobic surfaces is poorly understood. We utilize graphene templating to preserve and visualize the microscopic structures of adsorbed water on hydrophobic surfaces. Three well-defined surfaces [H-Si(111), graphite, and functionalized mica] were investigated, and water was found to adsorb as nanodroplets (∼10-100 nm in size) on all three surfaces under ambient conditions. The adsorbed nanodroplets were closely associated with atomic-scale surface defects and step-edges and wetted all the hydrophobic substrates with contact angles<∼10°, resulting in total water adsorption that was similar to what is found for hydrophilic surfaces. These results point to the significant differences between surface processes at the atomic/nanometer scales and in the macroscopic world.
authors: Kavli Nanoscience Institute and Division of Chemistry and Chemical Engineering, California Institute of Technology, MC 127-72, Pasadena, California 91125, United States.
authors: Peigen
authors: P
authors: Cao
authors: Ke
authors: K
authors: Xu
authors: Joseph O
authors: JO
authors: Varghese
authors: James R
authors: JR
authors: Heath
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D014867:Water; D006108:Graphite; C011934:mica