• Title/Summary/Keyword: ACE-27

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Electrochemical Characteristics of Polyoxometalate/Polypyrrole/Carbon Cloth Electrode Synthesized by Electrochemical Deposition Method (전기화학 증착법에 의해 합성된 폴리옥소메탈레이트/폴리피롤/탄소천 전극의 전기화학적 특성)

  • Yoon, Jo Hee;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • v.27 no.4
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    • pp.421-426
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    • 2016
  • In this report, polyoxometalte (POM)-doped polypyrrole (Ppy) was deposited on surface of three-dimensional carbon cloth (CC) using an electrodeposition method and its pseudocapacitive behavior was investigated using cyclic voltammetry and galvanostatic charge-discharge. The POM-Ppy coating was thin and conformal which can be controlled by electrodeposition time. As-prepared POM-Ppy/CC was characterized using scanning electron microscope and energy-dispersive X-ray spectroscopy. The unique 3D nanocomposite structure of POM-Ppy/CC was capable of delivering excellent charge storage performances: a high areal capacitance ($561mF/cm^2$), a high rate capability (85%), and a good cycling performance (97% retention).

Synthesis of Polyimides Derived from 2,2-Bis[4-(4-aminobenzoyl)phenoxy]hexafluoropropane and Aromatic Dianhydrides (2,2-Bis[4-(4-nitrobenzoyl)phenoxy]hexafluoropropane과 방향족 이무수물을 사용한 폴리이미드의 합성)

  • Park, Jung Hye;Ahn, Byung Hyun
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.50-55
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    • 2016
  • Aromatic diamines containing hexafluoroisopropylidene and ester moiety were synthesized from 4,4'-hexafluoroisopropylidene diphenol and nitrobenzoyl chloride. The reaction of aromatic diamines with hexafluoroisopropylidene phthalicdianhydride (6FDA) or pyromellitic dianhydride (PMDA) gave four kinds of poly(amic acid)s. Their inherent viscosities ranged from 0.196 to 0.346 dL/g. Poly(amic acid)s were converted to polyimides by thermal imidization. The glass transition temperatures ($T_g$) of polyimides were between 241 and $289^{\circ}C$. The 5% weight loss temperatures were recorded in the range of $430{\sim}492^{\circ}C$. The tensile strength of polyimide films were measured as 29.84~64.38 MPa.

Production of Furfural and its Application in Biorefinery (Biorefinery 산업과 Furfural 생산 및 응용 분야)

  • Kim, Seung-Soo
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.10-15
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    • 2016
  • In this new energy economy era, the importance of renewable energy resource needs to be highly addressed, as the demand of energy dramatically increases and fossil fuel is being exhausted. Lignocellulosic biomass is considered as the sustainable and renewable feedstock to produce biochemicals and biofuels that are the alternative for petroleum derived products. Furfural is a natural precursor for the range of furan based chemicals and solvents such as methylfuran, tetrahydrofuran, methyltetrahydrofuran, ethyltetrahydrofuryl ether, ethyl levulinate, levulinic acid, and alkanes. Thus, furfural should be a renewable platform chemical for biochemicals and renewable biofuels. In this paper, the concept of biorefinery, furfural production and its applications are briefly reviewed.

Trends of Environment-friendly Bioplastics (친환경 바이오 플라스틱의 동향)

  • Lee, Jaechoon;Pai, Chaulmin
    • Applied Chemistry for Engineering
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    • v.27 no.3
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    • pp.245-251
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    • 2016
  • Trends of bioplastics, especially biomass-based bioplastics which is one of the most promising ways to solve the depletion of fossil fuels and global warming problems, were investigated. Emerged bioplastic polymers such as polylacticacid (PLA), polyglycolicacid (PGA) for cosmetic additive, polyhydroxyalkanoate (PHA) produced by bacterial fermentation, and cost effective starch-based polymer were discussed with their general studies. Also recent technologies of environment-friendly bioplastics for packaging and construction materials as well as disposable hygienic goods were briefly reviewed.

Application of Silica-supported Ionic Liquid Catalysts to Cycloaddition of CO2 (CO2 부가반응에 적용된 Silica 담지 이온성 액체 촉매)

  • Kim, Dong-Woo;Kim, Hyeon-Gook;Cho, Deug-Hee
    • Applied Chemistry for Engineering
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    • v.27 no.3
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    • pp.239-244
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    • 2016
  • The catalytic applicability of various ionic liquids immobilized on different silica-supports such as amorphous, SBA, MCM and commercial silica for the cycloaddition of $CO_2$ and epoxides is reviewed in this work. The effects of different structures of supported ionic liquids and silica supports in the synthesis cyclic carbonate by the cycloaddition of $CO_2$ have been remarked. The studies revealed that ionic liquids possessing functional groups or metals exhibited increased catalytic performance towards cyclic carbonate synthesis. Moreover, the reusability of SSIL catalyst and mechanism for the cycloaddition of $CO_2$ were studied.

Development Trend of Biosensors for Antimicrobial Drugs in Water Environment (물 환경 내 항생제 약물 분석을 위한 바이오센서 개발 연구 동향)

  • Goh, Eunseo;Lee, Hye Jin
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.565-572
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    • 2016
  • While there have been great demands on improving domestic water pollution issues, the necessity for real time monitoring of particular drug residues in water resources has been raised since drug residues including antibiotics could provoke new trains of drug-resistant bacteria in water environments. Among many different types of drugs used for pharmaceutical treatment, antibiotics are considered to be one of the most hazardous to our ecosystem since they can rapidly promote the spreading of drug-resistant bacteria in water environments. In this mini-review, we will highlight recent developments made on creating in-situ sensing platforms for the fast monitoring of antibiotic residues in aquatic environmental samples focusing on optical and electrochemical techniques. Related recent technology developments and the resulting economy effects will also be discussed.

Ultraviolet Blocking Material Based on Silver-doped Hydroxyapatite (수산화인회석에 은이 도입된 자외선차단재료)

  • Pyo, Eunji;Kim, Youngyong;Kwon, Ki-Young
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.669-671
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    • 2016
  • Hydroxyapatite (HAP) was prepared by a hydrothermal synthesis method and also silver was introduced on the surface of HAP through an ion exchange reaction. The crystal phase and morphology of HAP were then evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the absorption property of HAP was characterized by diffuse reflectance UV-Vis spectroscopy. The presence of silver nanoparticles on the surface of HAP was also verified by XRD and TEM analysis. Particularly, the silver doped HAP showed an enhanced absorption property in UV-Vis region compared to that of the pristine HAP.

Practical Process Development of AMCA from Recyclable Source MFB (재사용이 가능한 MFB로부터 AMCA의 합성 공정 개발)

  • Kim, Jong Cheon;Ryu, Young;Kim, Seok Chan
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.508-511
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    • 2016
  • A facile synthesis of 4-(aminomethyl)cyclohexanecarboxylic acid (AMCA) from recyclable methyl 4-formylbenzoate (MFB) was described. In particular, we investigated the best process variables such as catalyst, hydrogen pressure, reaction temperature, and reaction time for AMCA conversion from AMBA through hydrogenation reaction. The best conditions were found to be as follows: the catalyst as [5% Pd/C, 5% Pt/C, 5% Rh/C (1 : 1 : 1)] which is a composite catalyst, the pressure as 30 bar, the reaction time as 8 hours and the reaction temperature at $130^{\circ}C$. Under the condition, a 90% yield (purity 99.9%) for the mass production of AMCA was achieved.

Dependence of the Morphology of Hydroxyapatite on pH and Solvent Species (용액의 산도 및 용매의 종류에 따른 수산화인회석의 형태 변화 연구)

  • Kim, Youngyon;Kwon, Ki-Young
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.543-545
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    • 2016
  • Four different hydroxyapatites (HAP) were prepared by a solvothermal method under different pHs and solvent species. The synthesized hydroxyapatites were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Four HAPs exhibited similar XRD patterns regardless of synthetic conditions. However, the morphology of hydroxyapatites was dependent of pH and solvent species under synthetic condition. The HAP prepared in pH 12 showed an elongated shape along the [001] direction compared to that prepared in pH 8. Also, the morphology of the HAPs synthesized in the presence of methanol and ethanol exhibited the more elongated hexagonal rod shape along the [001] direction with the high aspect ratio.

Influence of Cation Part of Ionic Liquids on Silver Particle Structure (이온성액체의 양이온이 은 입자 구조 형성에 미치는 영향)

  • Yun, Mi Hee;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.551-554
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    • 2016
  • Silver particles were synthesized by chemical reduction with ionic liquids. Structure of silver particles were significantly affected by the cation parts of the ionic liquids. With increasing the length of the cation part, the smaller silver particles were formed regardless of the anion type. This is mainly attributed to the different stability of the ionic liquid structure formed by physical bond between cation parts. Among seven ionic liquids, [Omim][$PF_6$] was the most effective for synthesizing silver particles.