• 한국세라믹학회지
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• 제53권4호
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• pp.411-416
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• 2016

Benzothienobenzothiophene ($C_8-BTBT$) is a soluble organic small molecule material with high crystallinity resulting from its strong self-organizing properties. In addition, the high mobility and easy fabrication of $C_8-BTBT$ make it very attractive in terms of organic thin-film transistors. In this work, we made $C_8-BTBT$ thin films by using the zone-casting method; we also used an organic solvent to treat the devices with solvent vapor annealing to improve the electrical properties. As a result, we confirmed improved mobility, threshold voltage, and subthreshold swing after solvent vapor annealing. To prove the effect of solvent vapor annealing, we used the simultaneous extraction model to extract the contact resistance from the current-voltage curve. We confirmed that the electrical properties improved with decreasing contact resistance.

• Carbon letters
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• 제15권3호
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• pp.187-191
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• 2014

This study reports on the influence of N-butyl-N-methylpyrrolidinium tetrafluoroborate ($PYR_{14}BF_4$) ionic liquid additive on the conducting and interfacial properties of organic solvent based electrolytes against a carbon electrode. We used the mixture of ethylene carbonate/dimethoxyethane (1:1) as an organic solvent electrolyte and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a common salt. Using the $PYR_{14}BF$ ionic liquid as additive produced higher ionic conductivity in the electrolyte and lower interface resistance between carbon and electrolyte, resulting in improved capacitance. The chemical and electrochemical stability of the electrolyte was measured by ionic conductivity meter and linear sweep voltammetry. The electrochemical analysis between electrolyte and carbon electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.545-549
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• 2001

We have produced electrolyte solution out of 1.15M $LiPF_6$ EC/EMC/DEC/PC(30/55/10/5 by vol%) as a reference, and at the same time, performed basic physical property test using a single solvent of 1.15M $LiPF_6$ DEC, DMC, EMC and a 2 component electrolyte solution of 1.15M $LiPF_6$ EC/DEC(1/2 by vol%) and PC/DEC(1/2 by vol%). Cyclic Voltammetry Analysis showed that, compared to existing carbonate organic solvent, the addition of DEC,DMC and EMC brought the de-decomposition peak of salt anion of $PF_6$ and the solvent at lower oxidization potential of 2.3V, 0.7V and 2.1V(vs. $Li/Li^+$). In addition, a kinetics current peak, in which intercalation of Lt is proceeded at 750mV, 450mV(vs. $Li/Li^+$), was confirmed. These findings suggest that the DEC solvent decomposition occurred at an electric potential lower than that of oxidization of existing carbonate organic solvent. Through the impedance analysis, we checked electric charge transfer resistance($R_{ct}$) according to the electric potential of $Li^+$ intercalation at 750mV(vs. $Li/Li^+$), which was the same as the resistance ($R_f$) and cyclic voltammetry of SEI film that was formed at Reference. By doing so, we found that the significant decrease of polarization resistance($R_p$) when Reference was played a part in the formation of compact SEI layer at the initial decomposition reaction.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.545-549
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• 2001

We have produced electrolyte solution out of 1.15M LiPF$\sub$6/ EC/EMC/DEC/PC(30/55/10/5 by vol%) as a reference, and at the same time, performed basic physical property test using a single solvent of 1.15M LiPF$\sub$6/DEC, DMC, EMC and a 2 component electrolyte solution of 1.15M LiPF$\sub$6/ EC/DEC(1/2 by vo%%) and PC/DEC(1/2 by vol%). Cyclic Voltammetry Analysis showed that, compared to existing carbonate organic solvent, the addition of DEC, DMC and EMC brought the de-decomposition peak of salt anion of PF$\sub$6/$\^$-/ and the solvent at lower oxidization potential of 2.3V, 0.7V and 2.1V(vs. Li/Li$\^$+/\`). In addition, a kinetics current peak, in which intercalation of Li$\^$+/ is proceeded at 750mv, 450mv(vs. Li/Li$\^$+/), was confirmed. These findings suggest that the DEC solvent decomposition occurred at an electric potential lower than that of oxidization of existing carbonate organic solvent. Through the impedance analysis, we checked electric charge transfer resistance(R$\sub$ct/) according to the electric potential of Li$\^$+/ intercalation at 750mv(vs. Li/Li$\^$+/), which was the same as the resistance (R$\sub$f/) and cyclic voltammetry of SEI film that was formed at Reference. By doing so, we found that the significant decrease of polarization resistance(R$\sub$p/) when Reference was played a part in the formation of compact SEI layer at the initial decomposition reaction.

• Korea-Australia Rheology Journal
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• 제14권2호
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• pp.71-76
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• 2002

Metal thin films, which are indispensable constituents of ULSI (Ultra Large Scale Integration) circuits, have been fabricated by physical or chemical methods. However, these methods have a drawback of using expensive high vacuum instruments. In this work, the fabrication of tungsten metal film by spin coating was investigated. First of all, inorganic peroxopolytungstic acid (W-IPA) powder, which is soluble in water, was prepared by dissolving metal tungsten in hydrogen peroxide and by evaporating residual solvent. Then, the solution of W-IPA was mixed with organic solvent, which was spin-coated on wafers. And then, tungsten metal films, were obtained after reduction procedure. By selecting an appropriate organic solvent and irradiating UV, the sheet resistance of the tungsten metal film could be remarkably reduced.

• 한국막학회:학술대회논문집
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• 한국막학회 1994년도 추계 총회 및 학술발표회
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• pp.62-63
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• 1994

The membrane technology is more convenient and economical way in the separation field than conventional technology such as distillation, extration, crystallization, and so on. Therefore, membrane are used as efficient tools for the separation and concentration of molecular mixture in many industrial area. Although the polymeric membrane have various advantage, they have disadvantages as well. One of them is a poor resistance to organic solvent. Therefore, organic solvent resistant membranes were prepared by soluble polyimide. prepared by phase inversion method. The membranes were The homogeneous polymer solutions were obtained by the two different method ; the one is that the polymer sythesized was completely dissolved in a solvent to prepare a membrane casting solution, the other is that a membrane casting solution was prepared by the unit process from the viscose solution of polymerization.

• International Journal of Safety
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• 제9권1호
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• pp.43-46
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• 2010

In the recycle process of organic solvent, the atmospheric oxygen can cause autoxidation and product peroxide. The time-saving method to evaluate the hazards has been required. In this study, oxygen pressure monitoring experiment was proposed as a new method to evaluate autoxidative resistances of solvents. Some of organic solvents were pressurized by oxygen and kept under isothermal condition. At the same time, the pressure in the vessel tracked. Iodometrical titration, thermal analysis and spectroscopic analysis were performed to measure peroxide concentration, the heat of reaction and chemical bonding change. From the results that THF has larger oxygen consumption rate than CPME, it is considered that autoxidative resistance of THF is lower than that of CPME. This method enables to obtain results in shorter time than other methods. These experimental results were consistent with the previous research with longer test durations [1-2].

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.466-470
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• 2014

In this paper, organic solvent electrolytes were prepared by a mixture of propylene carbonate (PC), dimethyl carbonate (DMC), tetraethylammonium tetrafluoroborate ($TEABF_4$)s to evaluate the ionic properties of propylene carbonate (PC)/dimethyl carbonate (DMC) mixtures as solvents for a capacitor application, in view of improving the electrochemical performances. The bulk resistance and interfacial resistance of the mixture electrolytes were investigated using an AC impedance method. The morphology of carbon-based electrodes which were contained in different electrolytes was analyzed by scanning electron microscopy (SEM) method. From the experimental results, by increasing the FEC content, capacitance of electrodes was increased, and the interfacial resistance was decreased. In particular, by a content of 2 vol % FEC in 0.2 M $TEABF_4$ PC/DMC solvent, the electrolyte showed the superior capacitance. However, when FEC content exceeds 2 vol %, the capacitance was decreased and the interfacial resistance was increased.

• 한국건축시공학회지
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• 제17권5호
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• pp.437-444
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• 2017

개량 아스팔트 방수시트 위에 폴리 우레탄 도막방수재가 도포되는 복합방수공법의 경우 시공성 향상을 위하여 도막 방수재에 유기용제를 희석해 사용하고 있지만, 유기용제가 폴리 우레탄 도막방수재의 완전 경화 전에 전부 휘발되지 못하고 시트재와 도막재 사이에 잔류하게 되고 이는 아스팔트 층을 융해시켜 방수층 손상 및 누수문제를 발생시켰다. 이에 용제에 의한 융해 문제를 개선하기 위해 내용제성이 강한 PA 필름을 개량 아스팔트 시트에 코팅(적층)하였고, 그 결과 융해에 대한 안전성을 육안을 관찰하였고, SEM 분석, EDX 분석을 통하여 PA 필름에 대한 내용제성을 정량적으로 확인하였다.

• 공업화학
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• 제28권4호
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• pp.420-426
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• 2017

최근 특정 용매에 대한 저항성이 있고 특정 분획분자량을 가지는 고분자 분리막을 통해 용매 또는 용질의 분리가 이루어지는 용매저항성 나노여과막에 대한 연구가 많이 이루어지고 있다. 이러한 분리막의 필수조건은 우수한 물성과 용매저항성을 가지는 것인데 현존하는 상업용 고분자 중 가장 내열성이 좋다고 알려진 폴리벤즈이미다졸은 고유의 용매저항성 역시 뛰어나지만 가교되었을 때 강한 유기용매에도 녹지 않는 특성을 가진다. 따라서 본 연구에서는 이러한 폴리벤즈이미다졸의 용매저항성을 이용한 나노여과막의 적용 가능성에 대하여 논의하고자 하였다. 분리막의 제조는 비용매유도상전이법을 통해 실시하였고 전계방출형 주사전자현미경을 통해 나노여과막으로서 적절한 복합막을 형성하는 것을 확인하였다. 또한, 가교유무에 따른 용매의 투과성능을 확인하였고 장시간 운전을 통하여 용매에 대한 내구성에 따른 안정성 또한 확인하였다. 투과도 실험은 물, 에탄올, 벤젠, N, N-dimethylacetamide (DMAc), n-methyl-2-pyrrolidone (NMP) 다섯 가지 용매에 의해 실시되었으며 각각의 초기 플럭스는 $6500L/m^2h$ (Water, 2 bar), $720L/m^2h$ (DMAc, 5 bar), $185L/m^2h$ (Benzene, 5 bar), $132L/m^2h$ (NMP, 5 bar), $65L/m^2h$ (Ethanol, 5 bar)를 나타내었고 분리막의 종류에 따라 2-5 bar의 압력을 적용하였다.