265557 Trappe-Zeo: Transferable Potentials for Phase Equilibria Force Field for All-Silica Zeolites

Tuesday, October 30, 2012: 4:12 PM
411 (Convention Center )
Peng Bai1, Michael Tsapatsis1 and J. Ilja Siepmann1,2, (1)Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, (2)Chemistry, University of Minnesota, Minneapolis, MN

The transferable potentials for phase equilibria (TraPPE) force field is extended to allow for the investigation of adsorption behavior in all-silica zeolites where the zeolite host is treated as a rigid framework.  The new TraPPE-zeo force field provides Lennard-Jones parameters and partial charges for the framework atoms.  As for other parts of the TraPPE force field, Lorentz-Berthelot combining rules are employed to determine the parameters for all cross interactions, making the TraPPE-zeo force field applicable to any sorbate compound as long as suitable Lennard-Jones parameters and partial charges are available to describe sorbate-sorbate interactions; a significant advantage over force fields that explicitly tabulate the individual cross interaction parameters.  The TraPPE-zeo force field is parameterized using a concurrent multi-dimensional fitting strategy to match a target set of experimental adsorption isotherms including n-alkanes, carbon dioxide, and ethanol as sorbates; that is, the TraPPE-zeo force field can treat the adsorption of non-polar, weakly polar, polar, and hydrogen-bonding compounds in a consistent manner.  High accuracy of adsorption isotherms is also found for a diverse set of validation compounds over a wide range of pressures and temperatures.

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See more of this Session: Development of Intermolecular Potential Models
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