• Title/Summary/Keyword: fluorinated

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Electrical Properties of FET using F16CuPc (F16CuPc를 이용한 FET의 전기적 특성 연구)

  • Lee, Ho-Shik;Park, Young-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.504-505
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    • 2008
  • We fabricated organic field-effect transistors (OFETs) based a fluorinated copper phthalocyanine ($F_{16}CuPc$) as an active layer. And we observed the surface morphology of the $F_{16}CuPc$ thin film. The $F_{16}CuPc$ thin film thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed the typical current-voltage (I-V) characteristics and capacitance-voltage (C-V) in $F_{16}CuPc$ FET and we calculated the effective mobility.

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Fluorine-19 NMR Spectroscopic Studies of Phenyl-fluorinated Iron Tetraarylporphyrin Complexes

  • Song, Byung-Ho;Yu, Byung-soo
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.981-985
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    • 2003
  • Fluorine-19 NMR solution measurements have been made for various phenyl-fluorinated iron porphyrin complexes. Large chemical shifts for phenyl fluorine signals of iron(III) and iron(II) are observed, and these signals are sensitive to electronic structure. The chemical shift differences in ortho-phenyl fluorine signals between high-spin ferric and low-spin ferric tetrakis(pentafluorophenyl)porphyrins are approximately 40 ppm, whereas the differences are approximately 7 ppm between high- and low-spin states of ferrous tetrakis(pentafluorophenyl)porphyrin complexes. Analysis of fluorine-19 isotropic shifts for the iron(III) tetrakis(pentafluorophenyl) porphyrin using fluorine-19 NMR indicates there is a sizable contact contribution at the ortho-phenyl fluorine ring position. Large phenyl fluorine-19 NMR chemical shift values, which are sensitive to the oxidation and spin states, can be utilized for identification of the solution electronic structures of iron(III) and iron(II) porphyrin complexes.

Synthesis and Characterization of Fluorinated Polyimides for Optical Waveguide Application

  • Han, Kwansoo
    • Macromolecular Research
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    • v.8 no.4
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    • pp.165-171
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    • 2000
  • Fluorinated polyimides with high thermal stability, low optical absorption loss in the optical communication wavelengths of 1.3 and 1.55㎛, and low birefringence and water absorption have been investigated for optical waveguide applications. These polyimides were prepared from 2,2-bis(3,4-dicar-boxyphenyl) hexafluoropropane dianhydride (6FDA) with 1,4-bis-(4-amino-2-trifluoromethyl-phenoxy) tetrafluorobenzene (ATPT) , 1,4-bis-(4-amino-2-trifluoromethyl-phenoxy) benzene (ATPB) , and 1,3-bis-(4-amino-2-trifluoromethyl-phenoxy ) 4,6-dichlorobenzene (ATPD ), respectively. The polyimides obtained had glass transition temperatures that ranged from 260 to 280$\^{C}$, and low water absorption less than 0.4% and low optical loss (> 0.2 dB/cm) at 1.3 and 1.55㎛. Birefringency values of polymer films ranged from 0.0041 to 0.0066.

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Influence of Quaternary Ammonium Anion Exchange Moieties onto Mechanical Properties of Radiation-grafting Anion Exchange Membranes (방사선그라프팅 음이온교환막의 기계적 물성에 대한 4차 암모늄 음이온교환기의 영향)

  • Ko, Beom-Seok;Sohn, Joon-Yong;Shin, Junhwa
    • Journal of Radiation Industry
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    • v.6 no.1
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    • pp.49-54
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    • 2012
  • Various anion exchange membranes were prepared by radiation graft copolymerization of vinylbenzyl chloride onto fluorinated films and subsequent quaternization with various tertiary amines such as trimethylamine, N,N-dimethylbuthylamine, N,N-dimethylaniline, and N-methylpiperidine. The quaternizations of the anion exchange membranes were confirmed by measuring of the ion exchange capacities of the membranes. The mechanical properties and the water uptakes were also measured. The elongation at break was found to be largely dependent on the fluorinated film, the quateranry ammonium, and the degree of grafting. The results indicate that the poly (ethylene-alt-tetrafluoroethylene) with quaternized trimethylamine moiety exhibits higher flexible property compared to the other prepared anion exchange membranes.

Dopping Effect of Fluorine Atom on the Superconductivity of $YBa_2Cu_3O_{7-x}F_y$

  • Kim, Keu-Hong;Cho, Seun- Koo;Kim, Yoo-Young;Park, Jong-Sik;Choi, Mu-Yong
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.460-463
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    • 1990
  • The normal and fluorinated high-Tc superconducting materials, $YBa_2Cu_3O_{7-x}F_y$with $0.25{\leq}x{\leq}0.55\;and\;0.00{\leq}y{\leq}0.30$, were synthesized to investigate the dopping effect of fluorine atom on the superconductivity of Y123 and studied by X-ray diffraction analysis and electron probe microanalysis, resistivity and thermopower measurements, and polarized micro-Raman spectroscopy. The reproducible micro-Raman spectra were recorded and analyzed. The coherent assignments could be suggested for the spectra of normal and fluorinated samples. The fluorine atoms introduced were found to be substituted for oxygen in pyramidal Cu-O units rather than in Cu-O chains. The unit cell parameters were decreased upon the substitution of oxygen by fluorine atom. From the decreasing cell parameters and Tc, the increasing thermopower, and the possible assignments of the vibrational modes, it could be suggested that the dopping of fluorine atom localizes the superconducting electrons in Y123.

Adsorption Characteristics of Toluene Gas Using Fluorinated Phenol-based Activated Carbons (불소화 처리된 페놀계 활성탄소를 이용한 톨루엔 가스흡착 특성)

  • Kim, Min-Ji;Jung, Min-Jung;Kim, Min Il;Choi, Suk Soon;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.26 no.5
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    • pp.587-592
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    • 2015
  • Activated carbons (ACs) were treated by fluorination to improve the adsorption property of toluene gas among volatile organic compounds (VOCs). The pore characteristics and surface properties of these activated carbons were evaluated by BET and XPS and the adsorption property and removal efficiency of toluene gas was investigated by gas chromatography. The breakthrough time of fluorinated ACs was increased about 27% compared to that of untreated ACs when the toluene gas of 100 ppm was flowed at a flow rate of $300cm^3/min$. Fluorinated AC of 0.1 g adsorbent totally adsorbed toluene gas in 100 ppm to 100 % during the adsorption time in 19 h. These results can be used as a treatment technology or removal of carcinogenic materials such as toluene.