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Investigations of Electric Field Gradients and NMR Chemical Shifts of 87Sr in Mixed Calcium/Strontium Systems Using High Field NMR and Computational Chemistry


EMSL Project ID
30491

Abstract

Calcium (Ca) and strontium (Sr) both form divalent ions that share rich and important chemistries. In light of the importance of Sr for the DOE mission, we are studying the substitution of Sr into cation sites normally occupied by Ca to provide insight into the chemistry, solubility, and sequestration of Sr in various solids. In previous EMSL-based research (detailed in the proposal), we have successfully observed 87Sr NMR signals from Sr incorporated into fluoroapatite, at varying degrees of substitution, and are now attempting to understand the physicochemical basis of the measured NMR parameters (including chemical shift and quadrupolar coupling frequencies) for a number of different binding sites. We are approaching this study through the combined use of a model Sr/Ca carbonate solid solution coupled with high-field nuclear magnetic resonance spectroscopy. A novel aspect of this work will be the joining of experimental NMR characterization methods with large-scale computational chemistry modeling of the local environment of the Sr cations in an effort to understand the structural influences upon changes in NMR parameters.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2008-08-18
End Date
2011-09-30
Status
Closed

Team

Principal Investigator

Karl Mueller
Institution
Pacific Northwest National Laboratory

Team Members

Jinfeng Lai
Institution
Pacific Northwest National Laboratory

Mark Borkum
Institution
Pacific Northwest National Laboratory

Nancy Washton
Institution
Pacific Northwest National Laboratory

Eric Poweleit
Institution
Pennsylvania State University

William Brouwer
Institution
Pennsylvania State University