• Title, Summary, Keyword: NMR spectroscopy

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Structural Studies of Hydrotalcite Compounds Calcined with Different Temperatures by $^{27}Al$ Solid-state NMR Spectroscopy

  • Park, Tae-Joon;Kim, Yong-Ae
    • Journal of the Korean Magnetic Resonance Society
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    • v.11 no.1
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    • pp.42-47
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    • 2007
  • Several hydrotalcite compounds calcined with different temperature for applications in a chlorine resistant textile were prepared, and its structural changes in dependence on the temperature were studied by using $^{27}Al$ solid-state nuclear magnetic resonance(NMR) spectroscopy. We found that the Al coordination was partly lowered from octahedral to tetrahedral site as the calcined temperature goes up. And we also investigated the hydrotalcite-treated textile for chlorine resistance by using $^{27}Al$ solid-state NMR spectroscopy.

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NMR analysis of organic ligands on quantum-dots

  • Kim, Jin Hae
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.2
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    • pp.51-55
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    • 2019
  • Quantum dot (QD) is an emerging novel nanomaterial that has wide applicability and superior functionality with relatively low cost. Nuclear magnetic resonance (NMR) spectroscopy has been contributed to elucidate various features of QDs and to improve their overall performance. In particular, NMR spectroscopy becomes an essential analytical tool to monitor and analyze organic ligands on the QD surface. In the present mini-review, application of NMR spectroscopy as a superb methodology to appreciate organic ligands is discussed. In addition, it was recently noted that ligands exert rather greater influence on diverse features of QDs than our initial anticipation, for which contribution of NMR spectroscopy is briefly reviewed.

The Development of Quantification Technique for Brain In vivo Proton NMR Spectroscopy (뇌의 양성자 핵자기공명 분광학을 위한 정량화 방법 개발)

  • 강해진
    • Progress in Medical Physics
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    • v.12 no.1
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    • pp.31-39
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    • 2001
  • NMR spectroscopy enables us to measure the molar concentration of the metabolites in the organisms, and this technique is the only method to measure the concentration non-invasively. The proton NMR spectroscopy has been used to study the biochemical changes in human as well as in animal brain. MRI uses the proton densities and its relaxation times for reconstructing images, but MRS gives the biochemical changes inside the body. NMR spectroscopy could provide the information which MRI and CT could not, and this makes NMR spectroscopy more useful in diagnosing diseases. This study was tried to develop the quantitation of the molar concentration of the metabolites in the brain using the proton MR spectroscopy. The spectra of each metabolites was obtained, and the proton MR spectra was obtained from the insula gray matter areas of the 16 volunteers. And this spectra was analyzed to estimated the molar concentrations of the metabolites in the region. The results showed the very similar to those of the others.

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Characterization and Synthesis of Titanium (IV) Isopropoxide Derivatives (Titanium(IV) isoproxide 유도체의 합성 및 특성연구)

  • Jung, Mie-Won
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.509-514
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    • 1999
  • The systematic modification of titanium(IV) isopropoxide with acetic acid as a organic additive was done and identifided by FT-IR, $^1H$, $^{13}C$ NMR and UV-Vis spectroscopy. The structure was cbanged after hydrolysis-condensation reaction and drying process. The hydrolysis-condensation rates of modified Ti alkoxide with acetic acid were investigated by $^1H$ NMR spectroscopy. This modified Ti(IV) alkoxide was less reactive toward hydrolysis-condensation reaction than $Ti(OPr^i)_4$, which can be attributed to the stable ligand structure between Ti alkoxide and ligand. The structural change on obtained from gel powders with heat treatment was also observed by FT-IR spectroscopy.

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27Al Solid-state NMR Structural Studies of Hydrotalcite Compounds Calcined at Different Temperatures

  • Park, Tae-Joon;Choi, Sung-Sub;Kim, Yong-Ae
    • Bulletin of the Korean Chemical Society
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    • v.30 no.1
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    • pp.149-152
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    • 2009
  • Hydrotalcites are anionic clays that are quite prevalent in nature and their importance is growing more and more because of their very wide range of potential applications and uses. Understanding the structural and compositional changes that occur on the molecular scale during the thermal decomposition of hydrotalcite compounds is essential for the basic prediction and comprehensive understanding of the behavior and technical application of these materials. In this study, several hydrotalcite compounds calcined at different temperatures for applications in a chlorine resistant textile were prepared and 27-Aluminm solid-state nuclear magnetic resonance (NMR) spectroscopy was used as a tool to study their local structure and behavior. The changes in the Al coordination of the hydrotalcite compounds were investigated with one dimensional (1D) solid-state magic angle spinning (MAS) NMR spectroscopy. The two broad resonances arising from the structurally different Al coordinations of these compounds were clearly resolved by two dimensional (2D) triple quantum magic angle spinning (3QMAS) NMR spectroscopy.