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| UNC-CH Collaborators |
| Joseph DeSimone |
| Royce Murray |
| Johnson Group Recent Results | |
| Recent Result #1 | |
| We have developed a new type of NMR experiment called DOSY that permits NMR spectra of mixtures to be resolved on the basis of the size of molecules or aggregates. This method has been adopted by numerous laboratories and the associated software is now available from the major spectrometer vendors. | |
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| Recent Result #2 | |
| Our diffusion studies of certain block copolymer surfactants in liquid CO2 in the density region where micelles form indicate that the molecular unimers are exchanging between the micelles and bulk solution. The rate of exchange can be measured by NMR techniques. This finding is related to the stability of the micelles and their capacity for solubilization. | |
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| Recent Result #3 | |
| In the study of NMR spectra of ligands bonded to gold clusters (MPCs), we have discovered that the ligands are attached to two distinguishable types of nanocrystals that have different average sizes. The results are consistent with the presence of different crystal structures, Marks-decahedra and truncated octahedra, that have previous been reported. The frequency changes relative to those in the free ligands are probably related to Knight shifts, a well known NMR phenomenon in metals and molecules adsorbed on metals. |
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Last Updated:
August 10, 2007
© 2006 University of North Carolina at Chapel Hill Content Manager: chemcontent@unc.edu |