AVS 53rd International Symposium
    Surface Science Tuesday Sessions
       Session SS2-TuM

Paper SS2-TuM12
Interfacial Water Structure and Dynamics Probed with Chemical Force Microscopy

Tuesday, November 14, 2006, 11:40 am, Room 2004

Session: Water-Surface Interactions
Presenter: P.D. Ashby, Lawrence Berkeley National Laboratory
Authors: P.D. Ashby, Lawrence Berkeley National Laboratory
M. Salmeron, Lawrence Berkeley National Laboratory
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Understanding the structure and energetics of water at interfaces is important for many diverse fields of study including self-assembly of nanostructures, protein folding, tribology, and catalysis. Two novel methods for investigating interfacial water structure with the Atomic Force Microscope will be presented. First, Brownian Force Profile Reconstruction harnesses cantilever thermal motion to accurately and precisely reconstruct equilibrium force profiles. Experiments between solvated hydroxyl terminated self-assembled monolayers revealed highly oriented water structure which decayed into the bulk within three molecular layers. Second, Tapping Mode Force Profile Reconstruction computes the forces experienced by the advancing and receding tip surface during high frequency oscillation. Investigation of solvated hydrophilic surfaces revealed slow reordering dynamics in electrostatic doubles layers and fast reordering for less long range interactions.