• Title/Summary/Keyword: supramolecular polymer

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Lanthanide-Cored Supramolecular Systems with Highly Efficient Light-Harvesting Dendritic Arrays towards Tomorrow′s Information Technology

  • Kim, Hwan-Kyu;Roh, Soo-Gyun;Hong, Kyong-Soo;Ka, Jae-Won;Baek, Nam-Seob;Oh, Jae-Buem;Nah, Min-Kook;Cha, Yun-Hui;Jin Ko
    • Macromolecular Research
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    • v.11 no.3
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    • pp.133-145
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    • 2003
  • We have developed novel lanthanide-cored supramolecular systems with highly efficient light-harvesting dendritic arrays for integrated planar waveguide-typed amplifiers. Er$^{3+}$ ions were encapsulated by the supramolecular ligands, such as porphyrins and macrobicyclics. The supramolecular ligands have been designed and synthesized to provide enough coordination sites for the formation of stable Er(III)-chelated complexes. For getting a higher optical amplification gain, also, the energy levels of the supramolecular ligands were tailored to maintain the effective energy transfer process from supramolecular ligands to erbium(III) ions. Furthermore, to maximize the light-harvesting effect, new aryl ether-functionalized dendrons as photon antennas have been incorporated into lanthanide-cored supramolecular systems. In this paper, molecular design, synthesis and luminescent properties of novel lanthanide-cored integrated supramolecular systems with highly efficient light-harvesting dendritic arrays will be discussed.d.

Supramolecular Assembly toward Organic Nanostructures

  • Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.173-173
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    • 2006
  • We have explored a strategy to control the supramolecular nano-structures self-assembled from rigid segments through attachment of flexible chains through microphase separation and anisotropic arrangement. Supramolecular structures formed by self-assembly of rigid building blocks can be precisely controlled from 1-D layered, 3-D bicontinuous cubic to 2-D cylindrical structures by systematic variation of the type and relative length of the respective blocks. Furthermore, depending on the individual molecular architectures, rigid building blocks self-assemble into a wide range of supramolecular structures such as honeycomb, disk, cylinder, helix, tube, barrel stave, and nano-cage.

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Supramolecular Nanomaterials Derived from Self-Assembly of Dendritic Building Blocks

  • Park, Chi-Young;Lee, Sang-Wha;Lim, Ji-No;Lim, Moon-Seob;Kim, Chul-Hee
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.91-92
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    • 2006
  • The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.

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Supramolecular assembly of peptide molecules for applications in biological multivalent interactions

  • Lim, Yong-Beom;Park, So-Mi;Lee, Eun-Ji;Jeong, Hae-Mi;Ryu, Ja-Hyoung;Yang, Won-Young;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.265-265
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    • 2006
  • Multivalent interactions, which are characterized by the simultaneous binding of multiple ligands on multiple receptors, are prevalent in biological system. We have shown that it is able to make a supramolecular aggregate coated with multiple functional molecules fairly easily by simply mixing one building block. In this particular example, a mannose-coated object was able to agglutinate bacterial cells with cognate binding partners through multivalent interactions. This kind of strategy can be applied in developing materials that can selectively remove pathogens. Supramolecular assembly of this type should be very useful in exploring multivalent biological interactions.

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Complex Ordering of Supramolecular Dendrimers in Confined Geometries.

  • Yoon, Dong-Ki;Choi, Myung-Chul;Kim, Yun-Ho;Kim, Mahn-Won;Jung, Hee-Tae
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.189-189
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    • 2006
  • The self-assembly of supramolecular dendrimers allows the rapid construction of nanosized structures with regularly ordered features that depend on the shape of the molecules and the relative strength of the intra-and intermolecular interactions. Here we report on a dramatic improvement in the degree of control and selectivity in the orientation of fan-shaped supramolecular molecules over a large area, which has been achieved by confined geometries and applied fields. The order and orientation of supramolecular dendrimers can be controlled by surface anchoring in confined geometries. POM, SEM, TEM, AFM and XRD results show that the molecules form the complicated defect-ordering in the microchannels with different feature sizes. We show that these defect domains are strongly influenced by the boundary and feature size of the surfaces. This technique can be used to create a grain size in the plane of the film that is much larger than that which can be achieved using previously reported soft-material based pattering.

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Revesible Switching between Nematic Gel and Isotriopic Fluid Triggered by External Stimuli in Aqueous Self-Assembly of Supramolecular Nanocylinders

  • Ryu, Ja-Hyoung;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.308-308
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    • 2006
  • We have demonstrated that the cylindrical micelles self-assembled from coil-rod-coil molecules can be interconnected by addition of a small amount of rod-coil-rod molecule as a bridging agent. Subsequently, these dynamic interconnections lead to stiff bundles composed of cylindrical micelles that are responsible for the formation of a reversible nematic gel. The results described here represent a significant example that dynamic bridging of supramolecular cylinders in aqueous solution can provide a useful strategy to construct one-dimensional nematic structure with three dimensional elastic properties.

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Folding of Coordination Polymers into Double-Stranded Helical Organization

  • Kim, Ho-Joong;Lee, Eun-Ji;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.248-248
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    • 2006
  • The notable feature of the Cu(II) coordination polymer investigated here is its ability to self-assemble into a double-stranded helical structure with regular grooves along the helical axis, through the combination of metal-chloride dimeric interactions and repulsive interactions, as an organizing force. It is also remarkable that the double-stranded helices self-organize into a 2-D columnar structure in both the bulk state and aqueous solution. These results represent a unique example that weak metal-ligand bridging interactions can provide a useful strategy to construct stable double-stranded helical nanotubes.

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Invertible Nanofibers with Tunable Stiffness from Self-Assembly of an Amphiphilic Wedge-Coil Molecule

  • Kim, Jung-Keun;Lee, Eun-Ji;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.249-249
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    • 2006
  • We have prepared an amphiphilic wedge-coil molecule consisting of a hydrophobic wedge-like segment and a hydrophilic poly(ethylene oxide) (PEO) segment. The wedge-coil block molecule self-assembles into cylindrical nanofibers in both polar as well as nonpolar solvents. Remarkably, the resulting nanofibers, as solvent polarity change from water to n-hexane, change from highly flexible coil-like to stiff rod-like characteristics. This dynamic switching in the stiffness of the nanofibers in response to solvent polarity is attributed to the structural inversion of cylindrical core from bulky dendritic segments with amorphous nature to crystallizable linear PEO segments.

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Supramolecular Liquid Crystals Containing Hydrogen Bond between Carboxylic Acid and Pyridyl Moieties and their Thermotropic Mesomorphism

  • Lee, Seung-Jun;You, Mi-Kyoung;Lee, Ji-Won;Lee, Shin-Woo;Jho, Jae-Young
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.297-297
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    • 2006
  • Recently columnar liquid crystals have been studied due to their possible application to organic conducting materials. Supramolecular columnar liquid crystals consist of mesogenic unit which can aggregate into discs that will make up the columns which associate to form a two-dimensional network. In this study, we prepared supramolecular columnar liquid crystals containing hydrogen bonding between carboxylic acid and, pyridine moieties. Thermal and structural properties of prepared complexe were investigated, and it exhibited hexagonal columnar structure ($Col_{h}$) at room temperature.

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