• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.874-876
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• 2003

Blue light-emitting polyfluorene derivatives, poly[9,9-bis(4'-n-octyloxyphenyl) fluorene] (PBOPF), poly[9,9-bis(2'-ethylhexyl)]fluorene (PBEHF) and copolymers of PBOPF and PBEHF were synthesized through Ni(0) mediated polymerization and their light-emitting properties were investigated. The PBEHF thin film showed significant excimer band in PL spectra after thermal annealing at 100 $^{\circ}C$ for 2h. But no significant excimer emission was observed in the PL spectra of the PBOPF and the copolymers even after thermal annealing suggesting that BOPF unit effectively suppressed the excimer emission.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1060-1061
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• 2003

We report photo- (PL), and electroluminescence (EL) realized via intrachain and interchain energy transfer in poly[9,9-(2'-octyl)fluorene-2,7-vinylene]-co-poly[2-methoxy,5-(2'-ethyl-hexyloxy)-1,4-phenylenevinylene] (PFV-co-MEH-PPV) copolymer systems. Energy transfer begins even at the device using 5 % MEH-PPV copolymer, and shows the best device performance for the 10 % MEH-PPV copolymer.

• Rubber Technology
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• v.13 no.1
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.87-92
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• 2003

Synchronous spectrofluorimetry was carried out for the simultaneous determination of various polycyclic aromatic hydrocarbons(PAHs) in aqueous solution by fluorescence spectrometry have been studied. The optimal wavelength interval(${\triangle}{\lambda}$) for synchronous spectra of acenaphthene, anthracene, benzo[a]anthracene, fluorene and pyrene were investigated in the presence of surfactants. The great enhancement of the fluorescence of these PAHs in Triton X-100 was obtained and optimal wavelength was 50 nm. The calibration curves in synthetic mixture solution of 5 PAHs were linear over the range from $1.0{\times}10^{-8}M$ to $1.0{\tiems}10^{-4}M$. Under the optimal experimental conditions, the detection limits were $4.9{\tiems}10^{-9}M$,\;7.0{\times}10^{-9}M,\;4.7{\tiems}10^{-9}M,\;1.6{\tiems}10^{-9}M$ and $3.2{\tiems}10^{-9}M$ for acenaphthene, anthracene, benzo[a]anthracene, fluorene and pyrene, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.721-723
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• 2002

We report a new red light emitting fluorene-based copolymer, poly{9,9-bis(2'-ethylhexyl)fluorene-2,7-diyl-co-2, 5-bis(2-thienyl-1-cyanovinyl}-1-(2'-ethylhexyloxy)-4methoxybenzene-5",5'''-diyl} (PFTCVB). The synthesized copolymers showed the absorption maxima at about 380 nm and the absorption between 425 and 600 nm increased as the fraction of the thiophene-containing monomer (BTCVB) increased. In PL, the emission maxima of the copolymers were red-shifted as the fraction of BTCVB increased, despite the similar absorption characteristics were shown in the UV-visible spectra. The copolymer containing 15 mol% of BTCVB showed a maximum PL and EL emission at 620 and 630 nm.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.513-517
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• 2014

Two donor-acceptor-donor monomers such as 3,5-bis(4-bromophenyl)-1,2,4-oxadiazole (BOB) and 3,5-bis(5-bromothiophen-2-yl)-1,2,4-oxadiazole (TOT) incorporating electron transporting and hole blocking 1,2,4-oxadiazloe moiety were copolymerized with light emitting fluorene derivative via Suzuki polycondensation to afford two new polymers, PFBOB and PFTOT, respectively. The optical studies for polymers PFBOB and PFTOT revealed that the band gaps are 3.10 eV and 2.72 eV, respectively, and polymer PFBOB exhibited a deep-blue emission while polymer PFTOT showed blue emission in chloroform and as thin film. The photoluminescence quantum efficiencies (${\Phi}_f$) of polymers PFBOB and PFTOT in chloroform calculated against highly blue emitting 9,10-diphenylanthracene (DPA, ${\Phi}_f=0.90$) were 1.00 and 0.44, respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.984-988
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• 2010

1-(Fluoren-2-yl)-benzo[d][1,2,3]triazoles 5a-b were synthesized starting from 2-nitrofluorene. 2-Nitrofluorenes 1a-b were reduced by catalytic hydrogenation, reacted with 2,4-dinitrofluorobenzene followed by catalytic hydrogenation to afford 2-(N-2,4-diaminophenyl)aminofluorenes 4a-b. Diazotization of 4a-b with $NaNO_2/H_2SO_4$ followed by treatment with $H_3PO_2$ gave 5a-b. Sulfonation of 5a-b yielded 7-benzotriazol-1-yl-fluorene-2-sulfonic acids 6a-b. The structures of 5b and 6b were firmly identified by X-ray crystal analysis in addition to $^1H$ NMR, $^{13}C$ NMR, and elemental analysis.

• Macromolecular Research
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• v.15 no.3
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• pp.216-220
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• 2007

A new polyfluorene-based copolymer having 2-ethylhexyloxy-5-methoxy-l,4-phenylene as an electron donating group and 2,5-diphenyl-oxadiazole as an electron withdrawing group was synthesized by the Suzuki coupling reaction. The obtained copolymer was characterized by $^1H-NMR,\;^{13}C-NMR$, and IR-spectroscopy. The weight average molecular weight ($M_w$) of the obtained polymer was 18,600 with a polydispersity index of 1.5. The maximum photoluminescence of the solution and film of the polymer was observed at 453 nm and 456 nm, respectively. A double-layer device with the configuration, ITO/PEDOT/copolymer/Al, emitted blue light at 460 nm.

• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.701-704
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• 2000

Fluorene and carbazole-containing distyrylarylene model and polymeric fluorophores were prepared by reacting 2,7-dibromo-9-butylfluorene and 3,6-dibromo-9-butylcarbazole with styrene and divinylbenzene using the Heck reaction for the chemiluminesc ence. The UV-vis absorbance, photoluminescence (PL) as well as the chemiluminescence (CL) characteristics of the model and polymeric fluorophores were measured. Sodium salicylate-catalyzed reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide produced a strong chemiluminescent blue light emission with 439-489 nm in the presence of the fluorophore. The wave-length of CL light was similar to that of photoluminescence. The chemiluminescent intensity was decayed according to the exponential equation.The glow of CL maintained more than 12 hr and was visible with naked eye.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.341-344
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• 1995

Laser-induced fluorescence (LIF) excitation spectra were measured for fluorene (FR) cooled in pulsed supersonic expansions of He in the range 283.7-296.7 nm. Ab initio studies of FR have also been carried out for determining the electronic and vibrational structures by using the standard 3-21G basis sets. In the LIF excitation spectra of FR, highly resolved vibronic bands are observed having the band origin of 33,791 cm-1. The vibrational bands above the electronic origin were assigned on the basis of the well-characterized electronic vibrational bands reported previously and of normal modes of vibrations derived by our HF/3-21G calculations.