AVS 56th International Symposium & Exhibition
    Surface Science Wednesday Sessions
       Session SS1-WeA

Paper SS1-WeA9
Water Growth on a Hydrophobic Substrate: Observation of a Metastable, Two-Layer Crystalline Ice on Graphene

Wednesday, November 11, 2009, 4:40 pm, Room M

Session: Water/Surface Interactions & Environmental Chemistry II
Presenter: G.A. Kimmel, Pacific Northwest National Laboratory
Authors: G.A. Kimmel, Pacific Northwest National Laboratory
J. Matthiesen, Pacific Northwest National Laboratory
M. Baer, Ruhr-Universität Bochum, Germany
C. Mundy, Pacific Northwest National Laboratory
N.G. Petrik, Pacific Northwest National Laboratory
R.S. Smith, Pacific Northwest National Laboratory
Z. Dohnálek, Pacific Northwest National Laboratory
B. Kay, Pacific Northwest National Laboratory
Correspondent: Click to Email
The structure of water at interfaces is crucial for processes ranging from photocatalysis to protein folding. Here, we investigate the structure and lattice dynamics of two-layer crystalline ice films grown on a hydrophobic substrate – graphene on Pt(111) – with low energy electron diffraction, reflection-absorption infrared spectroscopy, rare-gas adsorption/desorption, and ab-initio molecular dynamics. Unlike hexagonal ice, which consists of stacks of puckered hexagonal “bilayers”, this new ice polymorph consists of two flat hexagonal sheets of water molecules in which the hexagons in each sheet are stacked directly on top of each other. Such two-layer ices have been predicted for water confined between hydrophobic slits, but not previously observed. Our results show that the two-layer ice forms even at zero pressure at a single hydrophobic interface by maximizing the number of hydrogen bonds at the expense of adopting a non-tetrahedral geometry with weakened bonds.