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Sears, Jeremiah Matthew

Publications and source records attributed to Sears, Jeremiah Matthew.

15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Single-source synthesis of ceramic oxide nanoparticles

The tris(trimethylsilyl)silanol (H-SST) ligand can be reacted with a Group 4 or 5 metal alkoxides in a solvent to form an SST-modified metal alkoxide precursor. Exemplary Group 4 precursors include [Ti(SST)2(OR)2] (OR=OPri, OBut, ONep); [Ti(SST)3(OBun)]; [Zr(SST)2(OBut)2(py)]; [Zr(SST)3(OR)] (OR=OBut, ONep); [Hf(SST)2(OBut)2]; and [Hf(SST)2(ONep)2(py)n] (n=1, 2), where OPri=OCH(CH3)2, OBut=OC(CH3)3, OBun=O(CH2)3CH3, ONep=OCH2C(CH3)3, and py=pyridine. Exemplary Group 5 precursors include [V(SST)3(py)2]; [Nb(SST)3(OEt)2]; [Nb(O)(SST)3(py)]; 2[H][(Nb(μ-O)2(SST))6(μ6-O)]; [Nb8O10(OEt)18(SST)2.⅕Na2O]; [Ta(SST)(μ-OEt)(OEt)3]2; and [Ta(SST)3(OEt)2]; where OEt=OCH2CH3. When thermally processed, the precursors can form unusual core-shell nanoparticles. For example, HfO2/SiO2 core/shell nanoparticles have demonstrated resistance to damage in extreme irradiation and thermal environments.

Boyle, Timothy J.↗
DOE OSTI2017

Detection of Soluble Ligand-Tuned Molecular Tags for Subterranean Fluid Flow Monitoring Using Resonance Raman Spectroscopy

Our team has investigated a series of soluble coordination complexes for use as tags to monitor underground fluid flows in reservoirs. While most of the metal-ligand (M-L) complexes were based on the dianionic salen family of ligands, conceptually other ligands such as porphyrins or phthalocyanines could be used with similar success. Detection and identification of these species in solution were performed by inductively coupled plasma (ICP) or Raman/resonance Raman (rR) spectroscopy. The preparation of a large number of new M-L salen complexes was accomplished. Complexes were prepared that were soluble in either water or hydrocarbons to allow for flexibility in use. Unambiguous identification of these complexes allowed for meaningful molecular dynamics (MD) calculations to be performed, so that the attraction of the M-L complexes to either the rock formation or the liquid media could be evaluated. The use of soluble M-L species was found to avoid issues of rock deposition.

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