• 제목/요약/키워드: Nafion Solution

검색결과 84건 처리시간 0.029초

Optical Probe for Determination of Chromium(III) Ion in Aqueous Solution Based on Sol-Gel-Entrapped Lucigenin Chemiluminescence

  • Li, Ming;Kwak, Jun-Hee;Kim, Chang-Jin;Lee, Sang-Hak
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.103-108
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    • 2003
  • A method to determine chromium(III) ion in aqueous solution by chemiluminescence method using a lucigenin entrapped silica sol-gel film has been studied. An optical probe for chromium(III) ion has been prepared by entrapping lucigenin into silica sol-gel film coated on a glass support by dip coating. The chromium(III) optical sensor is based on the catalytic effect of chromium(IIII) ion on the reaction between lucigenin and hydrogen peroxide in basic solutions. The effects of Nafion, DMF and Triton X-100 were investigated to find the optimum condition to minimize cracking and leaching from the probe. The effects of pH and concentrations of lucigenin and hydrogen peroxide on the chemiluminescence intensity were investigated. The chemiluminescence intensity was increased linearly with increasing chromium(III) concentration from $2.5{\times}10^{-4}$M to $8.0{\times}10^{-7}$M and the detection limit was $4.0{\times}10^{-7}$M.

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Electrospun $SiO_2$ membrane using covalently cross-linked SPEEK/HPA by impregnation for high temperature PEMFC

  • 나희수;황형권;이찬민;설용건
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.85.2-85.2
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    • 2010
  • There is widespread effort to develop polymer membranes in place of Nafion for high temperature polymer electrolyte membrane fuel cell(PEMFC). In our study, SiO2 membranes are arranged by electrospinning method. For impregnation solution, the modified sulfonated poly(ether ether ketone)(SPEEK) polymer is prepared from sulfonation, sulfochlorination, partial reduction and lithiation reaction. The modified polymer is cross-linked with 1,4-diiodobetane in NMP solvent and then blended with Heteropoly acid(HPA). The characterization of membranes is confimed by FT-IR, Thermogravimetry(TGA), water uptake test and single cell performance test for PEMFC, etc. The composite membrane shows satisfactory thermal and mechanical properties. Beside, The membrane exhibits good ion exchange capacity and high proton conductivity. As a result, The composite membrane is promising as an alternative membrane in high temperature PEMFC.

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데칼법으로 제조된 고분자 연료전지용 전극 막 접합체의 성능평가 (enhanced performance of Membrane electrode assembly made by decal method)

  • 류성관;박석희;윤영기;이원용;김창수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.65-68
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    • 2007
  • 전극 막 접합체를 만드는 방법 중 연속식 공정으로서의 데칼법의 장점은 제조공정의 단순화와 두께 균일성 그리고 대량생산 등을 그 예로 들 수 있다. 본 실험에서는 코터를 이용해 전극 막 접합체를 만들기 위해 높은 점도의 촉매 슬러리를 제조하였다. Johnson Mattey 사의 HiSPEC 40 wt% Pt/C 촉매와 Dupont사의 20 wt% Nafion Solution 그리고 물을 이용하여 촉매 슬러리를 제조한 후 코터를 이용하여 데칼법으로 전극 막 접합체를 제조하였다. 완성된 전극 막 접합체의 성능 평가를 실시하였으며 상용화된 전극 막 접합체와 그 특성을 비교 분석을 실시해보았다.

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Enhanced Behaviors of Ionic-Polymer Metal Composite (IPMC) Actuator Coupled with Polymeric Anion-doped Polypyrrole Thin Film

  • Hong, Chan;Nam, Jae-Do;Tak, Yong-Sug
    • 전기화학회지
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    • 제9권4호
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    • pp.137-140
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    • 2006
  • In order to overcome the weak actuation and relaxation problems during the deformation of IPMC actuator, polymeric anion (polystyrenesulfonate)-doped polypyrrole(Ppy(PSS)) was electrodeposited onto IPMC actuator. Electrochemical quartz crystal microbalance study showed that hydrated cations were instilled into Ppy(PSS) film and polymeric-anion dopants introduced during polymerization were not expelled. Ppy(PSS)-coated IPMC actuator formed two electrode/electrolyte interfaces, Pt/nafion and Ppy(PSS)/bulk solution, and additive volume expansion phenomena at interfaces induced the large deformation compensating the relaxation of actuation by back diffusion of water.

플라즈마 중합법에 의해 제조된 불균일한 단면분포를 가진 이온교환막의 특성분석 (Characterization of inhomogeneous IEMs prepared by plasma graft polymerization)

  • Park, Eun-Young;Moon, Seung-Hyeon;Park, Yong-Jin
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 춘계 총회 및 학술발표회
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    • pp.53-56
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    • 2004
  • Morphology of membrane affects its performance [1]. For a constant amount of fixed charges, the distribution of these charges is also significant to its performance (2). In some ionomer membranes such as Nafion, the membrane fixed charge is not randomly distributed, but occurs in clusters. Thus, the membrane solution is phase-separated, with the ion clusters, acting as inverted micelles in a polymer solvent.(omitted)

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BDD전극을 이용한 해수에서의 NaOCl 생성 (NaOCl produced by electrolysis of seawater using BDD electrode)

  • 홍경미;박수길;타케요시 오카지마;타케오 오사카;아키라 후지시마
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.373-374
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    • 2005
  • NaOCl (Sodium hydrochlorite) have similar smell of chloride and solution of straw color. And boiling point is $110^{\circ}C$, specific gravity is 1.0(50g/l)/1.1(100g/l), Value of pH is 12. NaOCl playa role as bleach, a oxidizer, a germicide, a decolorant, a deodorant, treatment of water supply and drainage, food addition agent because strong oxidation, bleaching, sterilization effect is had. When NaOCl is produced in electrolysis of seawater, this system is composed of injection system by directly electrolysis of salt water on the spot and sodium hydrochlorite generate a safe low concentration(0.4~0.8 %).

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Synthesis and Characterization of Phase Pure NiO Nanoparticles via the Combustion Route using Different Organic Fuels for Electrochemical Capacitor Applications

  • Srikesh, G.;Nesaraj, A. Samson
    • Journal of Electrochemical Science and Technology
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    • 제6권1호
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    • pp.16-25
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    • 2015
  • Transition metal oxide nanocrystalline materials are playing major role in energy storage application in this scenario. Nickel oxide is one of the best antiferromagnetic materials which is used as electrodes in energy storage devices such as, fuel cells, batteries, electrochemical capacitors, etc. In this research work, nickel oxide nanoparticles were synthesized by combustion route in presence of organic fuels such as, glycine, glucose and and urea. The prepared nickel oxide nanoparticles were calcined at 600℃ for 3 h to get phase pure materials. The calcined nanoparticles were preliminarily characterized by XRD, particle size analysis, SEM and EDAX. To prepare nickel oxide electrode materials for application in supercapacitors, the calcined NiO nanoparticles were mixed with di-methyl-acetamide and few drops of nafion solution for 12 to 16 h. The above slurry was coated in the graphite sheet and dried at 50℃ for 2 to 4 h in a hot air oven to remove organic solvent. The dried sample was subjected to electrochemical studies, such as cyclic voltammetry, AC impedance analysis and chrono-coulometry studies in KOH electrolyte medium. From the above studies, it was found that nickel oxide nanoparticles prepared by combustion synthesis using glucose as a fuel exhibited resulted in low particle diameter (42.23 nm). All the nickel oxide electrodes have shown better good capacitance values suitable for electrochemical capacitor applications.

Anodic Stripping Voltammetric Detection of Arsenic(III) at Platinum-Iron(III) Nanoparticle Modified Carbon Nanotube on Glassy Carbon Electrode

  • Shin, Seung-Hyun;Hong, Hun-Gi
    • Bulletin of the Korean Chemical Society
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    • 제31권11호
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    • pp.3077-3083
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    • 2010
  • The electrochemical detection of As(III) was investigated on a platinum-iron(III) nanoparticles modified multiwalled carbon nanotube on glassy carbon electrode(nanoPt-Fe(III)/MWCNT/GCE) in 0.1 M $H_2SO_4$. The nanoPt-Fe(III)/MWCNT/GCE was prepared via continuous potential cycling in the range from -0.8 to 0.7 V (vs. Ag/AgCl), in 0.1 M KCl solution containing 0.9 mM $K_2PtCl_6$ and 0.6 mM $FeCl_3$. The Pt nanoparticles and iron oxide were co-electrodeposited into the MWCNT-Nafion composite film on GCE. The resulting electrode was examined by cyclic voltammetry (CV), scanning electron microscopy (SEM), and anodic stripping voltammetry (ASV). For the detection of As(III), the nanoPt-Fe(III)/MWCNT/GCE showed low detection limit of 10 nM (0.75 ppb) and high sensitivity of $4.76\;{\mu}A{\mu}M^{-1}$, while the World Health Organization's guideline value of arsenic for drinking water is 10 ppb. It is worth to note that the electrode presents no interference from copper ion, which is the most serious interfering species in arsenic detection.

Electro-oxidation Kinetics of Cerium(III) in Nitric Acid Using Divided Electrochemical Cell for Application in the Mediated Electrochemical Oxidation of Phenol

  • Matheswaran, Manickam;Balaji, Subramanian;Chung, Sang-Joon;Moon, Il-Shik
    • Bulletin of the Korean Chemical Society
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    • 제28권8호
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    • pp.1329-1334
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    • 2007
  • The electrochemical oxidation of cerium(III) was carried out using divided and undivided electrochemical cells in nitric acid medium. It was found that divided cell with Nafion 324 as the separator gave good conversion yield with high current efficiency compared to the undivided cell. The efficiency of the divided electrochemical cell was further optimized in terms of cell voltage, temperature, flow rate of solution recirculation, concentrations of Ce(III) and nitric acid. The better conditions for 1 M Ce(III) in 3 M nitric acid were found to be 2.5 V, 363 K and 100 mL/min recirculation flow rate based on the current efficiency under the experimental conditions investigated. The Ce(IV) oxidant produced was used as a mediator for the mineralization of phenol. The mineralization efficiency of the cerium mediated electrochemical oxidation was found rapid and higher compared to the direct electrochemical oxidation based on CO2 evolution under the same conditions.

Synthesis of Platinum Nanoparticles Using Electrostatic Stabilization and Cluster Duplication of Perfluorinated Ionomer

  • Lee, Pyoung-Chan;Kim, Dong-Ouk;Han, Tai-Hoon;Kang, Soo-Jung;Pu, Lyong-Sun;Nam, Jae-Do;Kim, Byung-Woo;Lee, Jun-Ho
    • Macromolecular Research
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    • 제17권3호
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    • pp.187-191
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    • 2009
  • Platinum (Pt) nanoparticles were prepared by the liquid-phase reduction of tetraammineplatinum (II) chloride $([Pt(NH_3)_4]Cl_2)$ using Nafion as a stabilizer under various conditions of the Nation phase. This method is novel in its use of electrostatic interactions between the Pt complex ions and sulfonic groups in the hydrated Nation molecules. The synthesized Pt nanoparticles of the recast film system had a cubic shape. In the case of the Nation solution system, the Pt nanoparticles mainly had a spherical shape. The shapes and sizes of the Pt nanoparticles were strongly influenced by the Nation phase.