• 제목, 요약, 키워드: Proton conductivity

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PSf-co-PPSS/HPA를 이용한 수소제조 수전해용 고체 고분자 전해질 복합 막의 제조 (Preparation of Solid Polymer Electrolytes of PSf-co-PPSS/Heterooolyacid [HPA] Composite Membrane for Hydrogen Production via Water Elecrolysis)

  • 정윤교;이혁재;장인영;황갑진;배기광;심규성;강안수
    • 한국수소및신에너지학회논문집
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    • v.16 no.2
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    • pp.103-110
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    • 2005
  • Proton conducting solid polymer electrolyte (SPE) membranes have been used in many energy technological applications such as water electolysis, fuel cells, redox-flow battery, and other electrochemical devices. The availability of stable membranes with good electrochemical characteristics as proton conductivity at high temperatures above 80 $^{\circ}C$ and low cost are very important for its applications. However, the presently available perfluorinated ionomers are not applicable because of high manufacturing cost and high temperature use to the decrease in the proton conductivity and mechanical strength. In order to make up for the weak points, the block copolymer (BPSf) of polysulfone and poly (phenylene sulfide sulfone) were synthesized and sulfonated. The electrolyte membranes were prepared with phosphotungstic acid (HPA)/sulfonated BPSf via solution blending. This study would be desirable to investigate the interaction between the HPA and sulfonated polysulfone. The results showed that the characteristics of SPSf/HPA blend membrane was a better than Nafion at high temperature, 100 $^{\circ}C$. These membranes proved to have a high proton conductivity, $6.29{\times}10-2$ S/cm, a water content, 23.9%, and a ion exchange capacity, 1.97 meq./g dry membrane. Moreover, some of the membranes kept their high thermal and mechanical stability.

Influence of Silica Content in Crosslinked PVA/PSSA_MA/Silica Hybrid Membrane for Direct Methanol Fuel Cell (DMFC)

  • Kim, Dae-Sik;Guiver, Michael D.;Seo, Mu-Young;Cho, Hyun-Il;Kim, Dae-Hoon;Rhim, Ji-Won;Moon, Go-Young;Nam, Sang-Yong
    • Macromolecular research
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    • v.15 no.5
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    • pp.412-417
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    • 2007
  • In the present study, crosslinked poly(vinyl alcohol) (PVA) membranes were prepared at different temperatures using poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA) (PVA:PSSA_MA = 1:9). The hybrid mem-branes were prepared by varying the TEOS content between 5 and 30 wt%. The PSSA_MA was used both as a crosslinking agent and the hydrophilic group donor ($-SO_3H$ and/or-COOH). The proton conductivity increased with up to 20 wt% TEOS, but decreased above this level, although the water content decreased with increasing TEOS content. This result suggests that the silica doped into the membrane improved the formation of proton-conduction pathways due to the absorption of molecular water. The PVA/PSSA_MA/Silica containing TEOS 20% showed both high proton conductivity (0.026 S/cm at $90^{\circ}C$) and low methanol permeability ($5.55{\times}10^{-7}cm^2/s$).

Reduction of Methanol Crossover in a Direct Methanol Fuel Cell by Using the Pt-Coated Electrolyte Membrane

  • Jung, Eun-Mi;Rhee, Young-Woo;Peck, Dong-Hyun;Lee, Byoung-Rok;Kim, Sang-Kyung;Jung, Doo-Hwan
    • 전기화학회지
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    • v.11 no.1
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    • pp.1-5
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    • 2008
  • A Pt-layer was deposited on the anode side of a Nafion membrane via a sputtering method in order to reduce methanol crossover in a direct methanol fuel cell (DMFC). The methanol permeation and the proton conductivity through the modified membranes were investigated. The performances of the direct methanol fuel cell were also tested using single cells with a Nafion membrane and the modified membranes. The Pt-layers on the membrane blocked both methanol crossover and proton transport through the membranes. Methanol permeability and proton conductivity decreased with an increase of the platinum layer thickness. At methanol concentration of 2 M, the DMFC employing the modified membrane with a platinum layer of 66 nm-thickness showed similar performance to that of a DMFC with a bare Nafion membrane in spite of the lower proton conductivity of the former. The maximum power density of the cell using the modified membrane with a platinum layer of 66 nm-thickness increased slightly while that of the cell with the bare membrane decreased abruptly when a methanol solution of 6M was supplied.

연료전지용 Poly(Styrene-Butadiene-Styrene) Star Triblock Copolymer의 고분자 전해질 분리막 (Polymer Electrolyte Membranes of Poly(Styrene-Butadiene-Styrene) Star Triblock Copolymer for Fuel Cell)

  • 에드윈 가르시아;정범석
    • 멤브레인
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    • v.29 no.5
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    • pp.252-262
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    • 2019
  • 서로 다른 술폰화 정도에 따라 sulfonated star branched poly(styrene-b-butadiene-b-styrene) triblock copolymer (SSBS)가 합성되었다. 술폰화된 butadiene block은 FT-IR spectroscopy로 확인할 수 있다. 술폰화 정도를 측정 비교하기 위해서 산-염기 적정을 통하여, ion exchange capacity (IEC)를 계산하였다. 술폰화된 SSEB 전해질막은 높은 water uptake와 proton conductivity를 보였다. 실온에서 25 mol% 술폰화된 SSBS는 0.114 S/cm라는 높은 값을 나타냈으며, 이는 Nafion과 비슷한 수치였다. 일정한 상대 습도에서 온도의 증가는 현저하게 높은 수소이온전도도를 나타냄을 알 수 있었다. 모든 술폰화된 막은 Nafion과 비교했을 때 낮은 methanol 투과도를 보여주었다. AFM을 이용하여 술폰화된 전해질막의 구조는 이른바 분리된 나노구조의 미세상과 ionic channel의 접속으로 이루어졌음을 확인할 수 있었다.

술폰화 폴리아릴렌에테르술폰/개질된 그라핀 복합막의 이온전도도 및 메탄올 투과도 (Proton Conductivity and Methanol Permeability of Sulfonated Poly(aryl ether sulfone)/Modified Graphene Hybrid Membranes)

  • 허훈;김득주;남상용
    • 멤브레인
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    • v.21 no.3
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    • pp.247-255
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    • 2011
  • 본 연구에서는 뛰어난 전도도와 물리적 강도를 가지는 그라핀의 고른 분산성을 얻기 위하여 두 가지 다른 방법으로 그라핀을 개질시켰다. 그리고 SPAES/그라핀 복합막은 각기 다른 함량을 첨가하여 제조되었으며 그라핀의 제조방법과 첨가된 그라핀의 함량에 따른 성능을 비교하였다. 복합막의 모폴로지는 SEM을 이용하여 관찰하였으며 개질된 그라핀의 화학적 구조는 FT-IR과 TGA를 사용하여 분석되었다. 그라핀의 함량변화가 0.5~3.0 wt% 일 때 복합막의 이온전도도와 메탄올 투과도를 측정하였으며 $80^{\circ}C$, 100% 가습상태에서 SPAES/그라핀 복합막의 이온전도도(0.216 S/cm)는 순수한 SPAES 전해질 막보다 높은 이온전도도(0.098 S/cm)를 나타내었으며 그라핀의 함량이 1.5 wt%까지 증가될 때 메탄올 투과도는 감소되었다.

Poly(vinyl alcohol)/poly(acrylic acid-co-maleic acid) 이온교환막에 이온전도도 향상을 hydroquinonesulfonic acid 첨가 연구 (Studies on the Addition of the Hydroquinonesulfonic Acid to Poly(vinyl alcohol)/poly(acrylic acid-co-maleic acid) Membranes to Improve the Ion Conductivity for Fuel Cell Applications)

  • 임지원;황호상
    • 멤브레인
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    • v.14 no.1
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    • pp.44-52
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    • 2004
  • 본 연구는 직접메탄을 연료전지(Direct Methanol Fuel Cell)에 적용가능한 양이온교환막 개발에 관한 것으로 poly(vinyl alcohol) (PVA)에 가교제로 poly(acrylic acid-co-maleic acid) (PAM)와 hydroquinonesulfonic acid (HQSA)를 이용하여 가교제의 함량을 변화시키면서 막을 제조하였다. 제조한 막은 가교제의 함량 변화에 따라 메탄을 투과도, 이온전도도를 측정하였으며 기본적인 이온교환막의 특성인 함수율, 이온교환용량 그리고 고정이온농도 등을 측정하였다. PAM 함량이 증가함에 따라 메탄을 투과도와 이온전도도 및 함수율이 조금 증가하는 추세를 보이다 9 wt%부터 감소하는 경향을 보였는데 이는 PAM의 친수성기보다는 가교효과의 영향이라 사료되며 HQSA 함량을 변화시켰을 때는 이온전도도, 함수율 그리고 이온교환용량이 전반적으로 증가하였는데 그 증가폭은 미비하였다.

Synthesis and Characterization of Sulfonated Poly(arylene ether) Polyimide Multiblock Copolymers for Proton Exchange Membranes

  • Lee, Hae-Seung;Roy Abhishek;Badami Anand S.;McGrath James E.
    • Macromolecular research
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    • v.15 no.2
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    • pp.160-166
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    • 2007
  • Novel multiblock copolymers, based on segmented sulfonated hydrophilic-hydrophobic blocks, were synthesized and investigated for their application as proton exchange membranes. A series of segmented sulfonated poly(arylene ether sulfone)-b-polyimide multiblock copolymers, with various block lengths, were synthesized via the coupling reaction between the terminal amine moieties on the hydrophilic blocks and naphthalene anhydride functionalized hydrophobic blocks. Successful imidization reactions required a mixed solvent system, comprised of NMP and m-cresol, in the presence of catalysts. Proton conductivity measurements revealed that the proton conductivity improved with increasing hydrophilic and hydrophobic block lengths. The morphological structure of the multiblock copolymers was investigated using tapping mode atomic force microscopy (TM-AFM). The AFM images of the copolymers demonstrated well-defined nanophase separated morphologies, with the changes in the block length having a pronounced effect on the phase separated morphologies of the system. The self diffusion coefficient of water, as measured by $^1H$ NMR, provided a better understanding of the transport process. Thus, the block copolymers showed higher values than Nafion, and comparable proton conductivities in liquid water, as well as under partially hydrated conditions at $80^{\circ}C$. The new materials are strong candidates for use in PEM systems.

고온 PEMFC용 메틸렌 사슬을 포함하는 폴리벤즈이미다졸 랜덤 공중합체의 합성과 특성 분석 (Synthesis and Characterization of Polybenzimidazole Random Copolymers Containing Methylene Chain for High Temperature PEMFC)

  • 한다은;유동진
    • 한국수소및신에너지학회논문집
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    • v.29 no.6
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    • pp.578-586
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    • 2018
  • In this study, we prepared the modified PBI random copolymer to reduce the problems of the pristine PBI about low solubility and proton conductivity. The random copolymer was synthesized from suberic acid, 5-aminoisophthalic acid, and 3,3'-diaminobenzidine to obtain $X_1Y_9$, $X_1Y_1$, $X_9Y_1$. Then, the membrane was fabricated by using solvent casting method with methanesulfonic acid at $140^{\circ}C$. Subsequently, the membrane was doped with phosphoric acid at $40^{\circ}C$. The chemical structure of the polymers was characterized by FT-IR. In addition, the physiochemical properties of the PBI were investigated by TGA, oxidative stability, acid uptake. Finally, the proton conductivity was measured at $100-180^{\circ}C$ without humidification. As the result, $X_1Y_9$ PBI random copolymer membrane showed higher conductivity.