Assessing competing theories of water dynamics over microscopic lengthscales

PHYS 309

Margaret E Johnson, and Teresa Head-Gordon, Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
Understanding the mechanisms by which water influences interactions at interfaces and in solutions requires understanding of the dynamics of bulk water over microscopic length scales. We investigated the TIP4P-Ew model and several water-like glass forming that conform to the microscopic Mode-Coupling theory (MCT), and compare them to Adams-Gibbs theory which relates the diffusivity of the liquid to thermodynamic quantities and the topography of the energy landscape. We report on the inability of the Adams-Gibbs relation to quantitatively describe the temperature dependence of the dynamics, and thus show that it does not support a connection between the time dependent predictions of MCT and landscape properties.

PHYS Poster Session - Water Mediated Interactions
7:30 PM-10:00 PM, Wednesday, August 20, 2008 Pennsylvania Convention Center -- Hall C, Poster

Division of Physical Chemistry

The 236th ACS National Meeting, Philadelphia, PA, August 17-21, 2008