• Korean Chemical Engineering Research
• /
• 제54권2호
• /
• pp.181-186
• /
• 2016

최근에 저가의 고분자 전해질 연료전지(Proton Exchange Membrane Fuel Cells, PEMFC)용 비불소계 전해질 막 연구개발이 활발히 진행되고 있다. 본 연구에서는 sulfonated Poly(ether ether ketone)(sPEEK)막의 특성을 술폰화도, 상대습도, 단위 전지 온도에 따라 PEMFC 운전 조건에서 비교하였다. I-V 분극곡선, 수소투과도, 전기화학적 표면적, 막 저항 및 부하 전달 저항 등을 측정 분석했다. 술폰화도와 온도, 상대습도가 높을수록 성능이 높았으며, 특히 낮은 슬폰화도와 낮은 상대습도에서 이온 전도도 감소 때문에 성능이 큰 폭으로 감소함을 확인하였다.

• 폴리머
• /
• 제36권2호
• /
• pp.155-162
• /
• 2012

전기방사 방법으로 sulfonated poly(ether ether ketone) (SPEEK) 나노섬유를 제조하고, 압축성형법으로 고분자 전해질막 연료전지(polymer electrolyte membrane fuel cell, PEMFC)용 나노섬유막을 제조하였다. SPEEK의 최대 설폰화율은 95% 이었고 초기 열분해 온도는 약 $280^{\circ}C$로 PEEK 보다 낮았으며 접촉각은 설폰화도가 증가함에 따라 감소하였다. 전기방사 나노섬유의 최적 인가전압, 유속, 방사거리(tip to collector distance, TCD) 및 농도는 각각 22 kV, 0.3 mL/hr, 5 cm, 23 wt% 이었고 평균 섬유직경은 47.6 nm 이었다. 한편, SPEEK 이온교환 나노섬유막의 함수율 및 이온교환용량은 설폰화 시간과 설폰화제 함량이 증가함에 따라 증가하였으며 최적값은 각각 20%, 2.03 meq/g으로 Nafion 117 보다 우수하였다. 막의 전기저항은 설폰화 시간이 증가함에 따라 감소하였고 그 값은 0.58~0.06 ${\Omega}{\cdot}cm^2$로 측정되었다. 또한 막의 수소이온전도도는 설폰화 시간이 증가함에 따라 증가하였으며 최대 0.099 S/cm로 Nafion 117 보다 우수하였다.

• Korean Chemical Engineering Research
• /
• 제57권1호
• /
• pp.17-21
• /
• 2019

산화환원흐름전지(Redox Flow Battery, RFB)는 대용량 에너지 저장장치로 바나듐 산화환원흐름전지가 대표적인 RFB인데, V-RFB는 고가인 점이 문제다. 철-크롬 RFB는 저가의 활물질(철, 크롬)을 사용해 경제적인 점이 장점인데, 성능이 낮은 점이 해결해야 할 과제다. 낮은 성능의 한 원인이 활물질의 크로스오버인데, 본 연구에서 불소계막 대신 탄화수소계막인 sulfonated Poly (ether ether ketone) (sPEEK)막을 사용해 활물질 투과를 감소시키는 연구를 하였다. sPEEK막의 크롬 이온 투과도는 $1.8{\times}10^{-6}cm^2/min$으로 Nafion막에 비해 약 1/33으로 작아서 불소계막 대신 sPEEK막을 사용하면 높은 활물질 투과문제를 해결할 수 있음을 보였다. 철 이온의 sPEEK막 확산의 활성화 에너지도 24.9 kJ/mol으로 Nafion막의 약 66%로 작았다. 그리고 고분자막에 들어간 e-PTFE 지지체가 철-크롬 산화환원흐름전지(ICRFB)에서 활물질 투과도를 감소시킴을 보였다.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.487-488
• /
• 2006

Novel bisphenol-based wholly aromatic poly(ether sulfone-ketone) copolymer containing pendant sulfonate groups were prepared by direct aromatic nucleophilic substitution polycondensation of 4,4-difluorobenzophenone, 2,2'-disodiumsulfonyl-4,4'-fluorophenylsulfone (40mole% of bisphenol A) and bisphenol A. Polymerization proceeded quantitatively to high molecular weight in N-methyl-2-pyrrolidinone at $180^{\circ}C$. Organic-inorganic composite membranes were obtained by mixing organic polymers with hydrophilic $SiO_2$ (ca. 20nm) obtained by sol-gel process. The polymer and a series of composite membranes were studied by FT-IR, $^1HNMR$, differential scanning calorimetry (DSC) and thermal stability. The proton conductivity as a function of temperature decreased as $SiO_2$ content increased, but methanol permeability decreased. The nano composite membranes were found to posse all requisite properties; Ion exchange capacity (1.2meq./g), glass transition temperatures $(164-183\;^{\circ}C)$, and low affinity towards methanol $(4.63-1.08{\times}10^{-7}\;cm^2/S)$.

• Bulletin of the Korean Chemical Society
• /
• 제32권9호
• /
• pp.3306-3310
• /
• 2011

A series of novel linear aromatic ether ketone polymers containing triazole units were synthesized by click chemistry and their structures and properties were characterized by FT-IR, $^1H$ NMR, GPC, TGA, DSC and WAXD. The results showed that these polymers exhibited relatively small molecular weights distributions, good thermal stability and solvent-repelling which could have potential applications as engineering thermoplastic.

• 한국전기화학회:학술대회논문집
• /
• 한국전기화학회 2005년도 수소연료전지공동심포지움 2005논문집
• /
• pp.83-86
• /
• 2005

• Fibers and Polymers
• /
• 제6권3호
• /
• pp.206-218
• /
• 2005

Structural studies of series of 'as spun' and drawn PEEK fibers have been carried out using X-ray diffraction and optical microscopy techniques. The analysis of results suggest that fibers produced at a constant draw ratio with increasing draw temperatures show enhanced orientation and crystalline behaviour. The resolved equatorial and meridional traces provide additional structural parameters in terms of crystallinity, crystallite size, and crystallite thickness. It is concluded that drawing at a temperature below $T_g(i.e.,\;144^{\circ}C)$ results in poorly oriented non-crystalline materials, whereas drawing above $T_g$ results in highly oriented semi crystalline materials. Additional drawing proved to increase the overall orientation with slight improvements in lateral order of the chain molecules. Quantitative analysis revealed that the crystallite size increases with increasing drawing temperature. The results also revealed the increased crystallite size upon additional drawing. Crystalline orientation parameter, $_c$, suggests almost perfect orientation. In all cases, the amorphous orientation is found to be lower than the overall orientation parameter obtained from the optical birefringence. As a result of additional drawing, crystalline orientation was found to increase slightly but the increase in the orientation of non-crystalline material was found to be substantial. An average crystalline density was determined from the orthorhombic unit cell dimensions. It was found to vary as a result of processing conditions. It was also found that the value of the maximum birefringence shows heavy dependence on the chain conformation.

• 한국수소및신에너지학회논문집
• /
• 제28권5호
• /
• pp.433-439
• /
• 2017

The high temperature performance of PEM type electrolyser at $120^{\circ}C$ based on covalently cross-linked sulfonated poly ether ether ketone (SPEEK) composie membrane was investigated. Ion conductivity and other properties of SPEEK membrane were improved by adding heteropoly acid and Ceria. The membrane electrode assemblies were prepared using commercial PtC and nano-sized $IrRuO_2$ catalyst by electro-spraying and decal process. Voltage efficiency of MEA equipped with SPEEK membrane was slightly better than that of $Nafion^{(R)}$ membrane, due to its higher proton conductivity at high temperature. The cell performance of MEA with CL-SPEEK/Cs-TSiA/Ceria is 1.71 V at $1A/cm^2$ and $120^{\circ}C$.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제5C권4호
• /
• pp.165-170
• /
• 2005

A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticle content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of the morphology, membranes are homogeneous and exhibit good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with the standard nafion membrane.

• Korean Chemical Engineering Research
• /
• 제45권4호
• /
• pp.391-395
• /
• 2007

술폰화한 폴리에테르에테르케톤(sPEEK)과 나피온(Nafion) 아이오노머를 혼합한 새로운 전극 바인더를 제조하여 DMFC 용 음극 바인더로서 적용 가능성을 고찰하였다. 새롭게 제조한 혼합 바인더는 높은 수소 이온 전도도와 메탄올 전달 속도 및 낮은 용해도와 우수한 기계적 물성을 나타냈다. 이를 도입한 음극에서 혼합 바인더 함량에 따른 셀 성능을 고찰하였으며, 10 wt% 혼합 바인더를 도입한 음극으로 구성된 셀이 가장 우수한 성능을 나타냈다.