• Title/Summary/Keyword: Functional characterization

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Synthesis, End-Functionalization and Characterization of Hyperbranched Polysiloxysilanes from $AB_3$ Type Monomer

  • Ishida, Yoshihito;Yokomachi, Kazutoshi;Seino, Makoto;Hayakawa, Teruaki;Kakimoto, Masa-aki
    • Macromolecular Research
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    • v.15 no.2
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    • pp.147-153
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    • 2007
  • Hyperbranched polysiloxysilanes (HBPSs), with a variety of terminal functional groups (vinyl, epoxy, carboxyl and hydroxyl), were synthesized by the self-polymerization of an $AB_3$ type monomer of tris(dimethylvinylsiloxy) silane, with subsequent end-functionalizations, such as epoxidation and radical addition reaction, respectively. The ratio of the $\alpha-and$ $\beta-addition$ linkages in the HBPS polymerized by hydrosilylation of the $AB_3$ monomer was found to be approximately 1 to 3. The thermal stability and solubility were affected by the terminal functional groups.

Cloning, Characterization, and Functional Analysis of Maize DEHYDRIN2

  • Paek, Nam-Chon;Jung, Hun-Ki
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.2
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    • pp.116-122
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    • 2002
  • Dehydrins (LEA Dll proteins) are one of the typical families of plant proteins that accumulate in response to dehydration, cold stress, abscisic acid, or during seed maturation. A 1.3-kb cDNA was cloned from a cDNA expression library of 5-day-old germinating maize scutellums under drought stress. The deduced protein sequence indicated a dehydrin gene encoding SK$_3$ LEA protein typically expressed during cold acclimation, but not by drought stress in barley and wheat. Thus, it was named maize DEHYDRIN2 (ZmDhn2). It accumulates rapidly and highly in drought-stressed scutellum and leaf tissues at any stage, but not under cold stress. ZmDhn2 gene was transformed into Arabidopsis thaliana for functional analysis under drought condition. From electrolyte leakage test, no significant difference showed between wild type and transformants under normal growth condition, but the leakage level of electrolyte in wild type plants was about 3 times as high as that in the transformed plants under drought stress. It suggests that ZmDHN2 playa role in increasing drought tolerance.

Synthesis, Characterization and Determination of HOMO-LUMO of the Substituted 1,3,5-Triazine Molecule for the Applications of Organic Electronics

  • Pakkath, Rajeesh;Reddy, Eeda Koti;Kuriakose, Sheena;Saritha, C;Sajith, Ayyiliath M;Karuvalam, Ranjith Pakkath;Haridas, Karickal Raman
    • Journal of the Korean Chemical Society
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    • v.63 no.5
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    • pp.352-359
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    • 2019
  • The most important parameter of organic molecules for energy harvesting application focuses mainly on their band gap (HOMO-LUMO). In this report, we synthesized differently substituted 1,3,5-triazine based organic molecule which on future processing can be used in organic electronics like solar cells and OLED's. The energy gap of the synthesized novel analogue was calculated using cyclic voltammetry, UV-Visible spectroscopy and compared with density functional theory (DFT) studies.

Electroactive Conjugated Polymer / Magnetic Functional Reduced Graphene Oxide for Highly Capacitive Pseudocapacitors: Electrosynthesis, Physioelectrochemical and DFT Investigation

  • Ehsani, A.;Safari, R.;Yazdanpanah, H.;Kowsari, E.;Shiri, H. Mohammad
    • Journal of Electrochemical Science and Technology
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    • v.9 no.4
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    • pp.301-307
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    • 2018
  • The current study fabricated magnetic functional reduced graphene oxide (MFRGO) by relying on ${FeCl_4}^-$ magnetic anion confined to cationic 1-methyl imidazolium. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid poly ortho aminophenol (POAP)/ MFRGO films have then been fabricated by POAP electropolymerization in the presence of MFRGO nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of MFRGO and POAP/ MFRGO composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability (capacitance retention of ~91% even after 1000 cycles). These results suggest that electrosynthesized composite films are a promising electrode material for energy storage applications in high-performance pseudocapacitors.

Preparation and Characterization of Ophthalmic Hydrophilic Silicone Lens Containing Zinc Oxide and Iron Oxide Nanoparticles

  • Shin, Su-Mi;Sung, A-Young
    • Korean Journal of Materials Research
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    • v.31 no.8
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    • pp.427-432
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    • 2021
  • This study uses silicone monomer, DMA, crosslinking agent EGDMA, and initiator AIBN as a basic combination to prepare hydrogel lenses using fluorine-based perfluoro polyether and iron oxide and zinc oxide nanoparticles as additives. After manufacturing the lens using iron oxide nanoparticles and zinc oxide nanoparticles, the optical, physical properties, and polymerization stability are evaluated to investigate the possibility of application as a functional hydrogel lens material. As a result of this experiment, it is found that the addition of the wetting material containing fluorine changes the surface energy of the produced hydrogel lens, thereby improving the wettability. Also, the addition of iron oxide and zinc oxide nanoparticles satisfies the basic hydrogel ophthalmic lens properties and slightly increases the UV blocking performance; it also increases the tensile strength by improving the durability of the hydrogel lens. The polymerization stability of the nanoparticles evaluated through the eluate test is found to be excellent. Therefore, it is judged that these materials can be used in various conditions as high functional hydrogel lens material.

A CHARACTERIZATION OF REFLEXIVITY OF NORMED ALMOST LINEAR SPACES

  • Im, Sung-Mo;Lee, Sang-Han
    • Communications of the Korean Mathematical Society
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    • v.12 no.2
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    • pp.211-219
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    • 1997
  • In [6] we proved that if a nals X is reflexive, then $X = W_X + V_X$ . In this paper we show that, for a split nals $X = W_X + V_X$, X is reflecxive if and only if $V_X$ and $W_X$ are reflcxive.

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Combinatorial Methods for Characterization and Optimization of Polymer Formulations

  • Amis Eric J.
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.110-111
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    • 2006
  • Most applications of polymers involve blends and mixtures of components including solvents, surfactants, copolymers, fillers, organic or inorganic functional additives, and various processing aids. These components provide unique properties of polymeric materials even beyond those tailored into the basic chemical structures. In addition, skillful processing extends the properties for even greater applications. The perennial challenge of polymer science is to understand and exploit the structure-processing-property interplay relationship. We are developing and demonstrating combinatorial methods and high throughput analysis as tools to provide this fundamental understanding.

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