• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2071-2076
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• 2009

The single-walled carbon nanotubes (SWCNTs) produced by chemical vapor deposition (CVD) were directly fluorinated with fluorine ($F_2$) gas in a temperature range 20 ~ 400 ${^{\circ}C}$. The surface properties and morphology of the SWCNTs were investigated in terms of fluorination temperature. As a result, Raman spectra showed a pair of bands at 1340 and 1590 $cm^{-1}$ peculiar to disordered $sp^2$-carbons. These results indicated that C-F bonds were formed on the rear surfaces of the nanotubes by fluorination, while the external surfaces as well as the layers between the internal and external surfaces retained their $sp^2$-hybridization. XPS analysis exhibited that fluorine atoms were bonded to carbon atoms on internal surfaces (rear surfaces) of the nanotubes and the amount of fluorine attached on the nanotubes was increased with increasing the fluorination temperature. Consequently, the direct fluorination of carbon nanotubes led to functionalization and modification of pristine nanotubes with respect to surface and morphological properties.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.303-304
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• 2009

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.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.24-29
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• 2017

A fluorinated polybenzimidazole (FPBI) was synthesized from 3,3-diaminobenzidine (DAB) of tetraamine, 2,2-bis(4-carboxyphenyl)hexafluoropropane of aromatic biscarboxylic acid, and 4,4-sulfonyldibenzoic acid of aromatic biscarboxylic acid in polyphosphoric acid (PPA). A FPBI was easily cast and made into clear films. The structure of condensation polymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (fourier transform infrared). TGA (thermogravimetric analysis) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. The proton conductivity of the FPBI membranes increased with increasing temperatures in the polymer. A FPBI membrane has a maximum ion conductivity of 45 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• Transactions on Electrical and Electronic Materials
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• 제15권4호
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• pp.221-225
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• 2014

Although gold wire bonding techniques have already matured in semiconductor manufacturing, weakly bonded wires in semiconductor chip assembly can jeopardize the reliability of the final product. In this paper, weakly bonded or failed aluminum bonding pads are analyzed using X-ray photoelectron spectroscopy (XPS), Auger electron Spectroscopy (AES), and energy dispersive X-ray analysis (EDX) to investigate potential contaminants on the bond pad. We found the source of contaminants is related to the dry etching process in the previous manufacturing step, and fluorocarbon plasma etching of a passivation layer showed meaningful evidence of the formation of fluorinated by-products of $AlF_x$ on the bond pads. Surface analysis of the contaminated aluminum layer revealed the presence of fluorinated compounds $AlOF_x$, $Al(OF)_x$, $Al(OH)_x$, and $CF_x$.

• Tribology and Lubricants
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• 제19권2호
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• pp.72-77
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• 2003

Chitosan derivatives, Fluorinated chitosan, and N,N,N-Trimethyl chitosan iodide were synthesized as the disperse phases for the electrorheological fluid. The synthesis of these materials were confirmed by Fourier transform infrared spectroscopy (FT-lR). Chitosan derivative suspensions showed ER effect under the electric field. Especially, N,N,N-Trimethyl chitosan iodide suspension showed better electrorheological and electric properties than Fluorinated chitosan. It is due to difference in electron strength of polar groups composed derivatives. N,N,N-Trimethyl chitosan iodide suspension exhibited a linear dependence on an electric field power of 2.07.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.471-473
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• 2006

An object of the present study is to provide a hollow fiber membrane humidifier capable of improving the humidification efficiency while lowering the pressure loss, and is suitably usable for PEMFC(Polymer Electrolyte Membrane Fuel Cell). The performance of PEMFC is decisively dependent on the humidity of the electrolyte membrane(fluorinated membrane) and a humidifier plays an important role in moisturizing electrolyte membrane. Especially this humidifier is adaptable for lower price to promote the commercialization of fuel cell vehicles and is passive type to be power free and to be volumetrically optimized. In this research, we propose the substitutes for the expensive fluorinated materials and the optimum dry-jet wet spinning conditions of hollow fiber membrane to get the fuel cell humidifier. In addition to that we established the standard method of evaluating the moisturizing performance of the humidifier of various materials.

• 폴리머
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• 제25권3호
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• pp.343-348
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• 2001

Perfluorinated polyether diol(Fomblin ZDOL$ZDOL^{(R)}$)과 4,4'-diphenyl methane diisocyanate(MDI)로부터 합성된 불소화된 폴리우레탄 탄성체의 기계적 성질과 혈소판 점착 특성을 연구하였다. Fomblin 함량과 혼합 사용된 polyether polyol의 종류에 따른 기계적 성질의 검토를 인장실험 및 dynamic mechanical analysis를 통해 행하였다. 또한 혈소판 점착실험을 통해 불소화된 폴리우레탄 탄성체의 혈액적합성을 평가하였다. 기계적 물성은 혼합된 polyether polyol의 종류와 함량에 영향을 받았고, 혈소판 점착은 모든 불소화된 폴리우레탄에서 불소화 함량의 증가에 따라 감소하였다.

• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 제16회 정기총회 및 동계학술발표회
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• pp.292-295
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• 2005

Variable optical attenuators (VOA) made of low-loss fluorinated polymers are demonstrated which shows a low operating power less than 30 mW due to the superior thermo-optic effect of polymer material and a low insertion loss less than 1.0 dB by incorporating highly fluorinated polymers to reduce the absorption loss at 1550 nm. An attenuator-integrated low-crosstalk polymeric digital optical switch (DOS) is also demonstrated. The switch and attenuator shares a single connected electrode which is controlled by a single current source. Due to the simple structure of the integrated attenuator, the device length is reduced to 1 cm so as to provide low insertion loss of 0.8 and 1.1 dB for 1300 and 1550 nm, respectively. The attenuator radiates remained optical signal on the switch-off branch in order to decrease the switching crosstalk to be less than -70 dB with an applied electrical power of 200 mW.

• Carbon letters
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• 제28권
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• pp.66-71
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• 2018

To improve the flame retardant performance of cellulose fibers, fluorine functional groups were introduced under various controlled fluorination conditions. The properties of the fluorinated cellulose fibers were analyzed by X-ray photoelectron spectroscopy and a thermogravimetric analysis. The fluorine functional group content in the fluorinated cellulose fibers increased with an increase in the fluorination temperature. However, the fluorination reaction increased the char yield and decreased the rate of degradation of the cellulose fibers by introducing donors, enabling the formation of a thick and compact char layer. Therefore, the flame retardant properties of cellulose fibers were improved following the fluorination treatment.

• Journal of Information Display
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• 제7권1호
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• pp.7-11
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• 2006

In this paper, we report the fabrication of high quality polymer walls by using a monomer containing fluorine (F-monomer). Polymer walls with no phase retardation were fabricated by using photo-polymerization induced anisotropic phase separation of the mixture composed of liquid crystal (LC) and F-monomer. Thanks to the immiscibility of fluoride, we could form high quality polymer walls with no light leakage. We measured electro-optic characteristics of a twisted-nematic (TN) LC cell whose polymer walls were fabricated by using the F-monomer, and the measurements were compared with that fabricated by using the monomer without fluorine.