• Title/Summary/Keyword: complexation

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Synthesis of Oxide Ceramic Powders by Polymerized Organic-Inorganic Complex Route

  • Lee, Sang-Jin;Lee, Chung-Hyo;Waltraud M. Kriven
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 2000.06a
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    • pp.151-163
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    • 2000
  • A polymerized organic-inorganic complexation route is introduced for the synthesis of oxide ceramic powders. Polyvinyl alcohol was used as the organic carrier for precursor ceramic gel. Porous and soft powders, which have a high specific surface area, were obtained after calcinating the aerated precursors. The PVA content and its degree of polymerization had a significant influence on the homogeneity of the final powder. In particular, attrition milling process with the porous powder resulted in ultra-fine particles. In the case of the preparation of cordierite powder, nano-size powder, which has a high specific surface area of 181 ㎡/g, was obtained by the milling process. The complexation route was also applied to the synthesis of unstable phase in room temperature like beta-cristobalite, high temperature form of silica.

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Liquid Crystal-based Imaging of Biomolecular Interactions at Roller Printed Protein Surfaces

  • Park, Min-Kyung;Jang, Chang-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1223-1227
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    • 2010
  • In this study, the orientational behavior of thermotropic liquid crystals (LC) supported on a film of protein receptors was examined. Avidin was roller printed and covalently immobilized onto the surface of gold using NHS/EDC chemistry. The orientation of nematic 4-cyano-4'-pentylbiphenyl (5CB) was found to be parallel to the plane of the printed avidin surface before incubation with a solution of biotin. However, protein-receptor complexation induced a random orientation of 5CB, where protein-receptor complexes disturbed the nanoscale topography of the printed protein surface. Atomic force microscopy and ellipsometry was used to confirm printing and the specific interaction of proteins. These results demonstrate that the combination of LC and roller printing can be used to detect specific interactions between biomolecules by manipulating the orientational behavior of LC to the printed protein surfaces.

Synthesis, Characterization and Complexation Behavior Investigations of Novel Bis- and Tris-crown Ethers

  • Huang, Zhi Bin;Kim, Sung-Hong;Chang, Seung-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.27 no.6
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    • pp.893-898
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    • 2006
  • Novel bis- and tris-crown ethers were synthesized from 1-aza and diaza-crown ethers with 2-acryloyloxy-methyl crown ethers through Michael addition. The synthesized bis- and tris-crown ethers were characterized by their elemental analyses, $^1H$-NMR, $^{13}C$-NMR, mass spectra, IR spectra, respectively. The complexation behavior of the bis- and tris-crown ethers with $Li^+$, $Na^+$, $Na^+$, $Rb^+$, $Cs^+$ was examined by $^1H$-NMR, FAB mass, and UV spectrometry.