Infrared Spectroscopic Investigations of Mixed-Metal Layered Hydroxides
EMSL Project ID
1733
Abstract
Mixed-metal layered hydroxides are among the few oxide-based materials that have significant permanent anion exchange capacity due to isomorphous substitution. They occur naturally and in cement systems, and are recieving increasing attention as potential waste remediation compounds, catalysts and catalyst supports, and drug delivery materials. We have undertaken considerable NMR and molecular dyanamics modeling of the behavior of the interlayer anions and water in these compounds and have made predictions about the low frequency vibrational modes due to these motions, which are key to understanding the anion exchange properties. Testing these predictions requires excellent infrared spectra, which can be obtained using the instrument at EMSL. We propose initial experiemtns using the Cl-containing Ca,Al compound, Friedel's salt, which is highly ordered and relatively well understood. We then expect to move to the Ca,Al compound with ohter interlayer anions (e.g., sulfate, nitrate, carbonate, selenate, selenite, and OH)and to a comparable range of Mg,Al compounds.
Project Details
Project type
Exploratory Research
Start Date
1999-11-02
End Date
2001-01-02
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Wang J, AG Kalinichev, JE Amonette, and RJ Kirkpatrick. 2003. "Interlayer Structure and Dynamics of Cl-Bearing Hydrotalcite: Far Infrared Spectroscopy and Molecular Dynamics Modeling." American Mineralogist 88(Feb-Mar 2003):398-409.