공기극과 연료극의 복합 황불순물에 의한 고분자 전해질막 연료전지의 성능에 미치는 영향

이수(Soo Lee),진석환(Seok-Hwan Jin) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.4

고분자 전해질막 연료전지는 연료극의 연료와 공기극의 공기에 각각 H2S와 SO2이 포함되어 있을 때 그 성능이 심각하게 감소한다. 본 연구는 고분자전해질막 연료전지의 공기극과 연료극에 1 ppm에서 10 ppm의 불순물 가스를 공급하여 전기적 성능측정을 통해 복합적인황불순물이 단위전지에 미치는 영향을 확인하였다. 최적의 운전조건에서 불순물가스를 피독하였을 때 SO2와 H2S의 농도가 증가할수록 성능이 급격히 감소하였다(단위전지 온도 65 ℃, 상대습도 100%). 그리고 황의 흡착은 MEA의 백금 촉매층 표면서 일어나며, 불순물 가스가 MEA에 누적되는것을 확인하였다. 1, 3, 5, 및 10 ppm 4회의 연속적인 피독 후 연료전지의 성능이 0.71 V에서 0.54V(76 %)로 감소하였다. Polymer electrolyte membrane fuel cell(PEMFC) performance degrades seriously when sulfur dioxide and hydrogen sulfide are contaminated in the fuel gas at anode and air source at cathode, respectively. This paper reveals the effect of the combined sulfur impurity poisoning on both PEMFC cathode and anode parts through measuring electrical performance on single FC operated under 1 ppm to 10 ppm impurity gases. The severity of SO2 and H2S poisoning depended on concentrations of impurity gases under optimum operating conditions(65℃ of cell temperature and 100 % relative humidity). Sulfur adsorption occured on the surface of Pt catalyst layer on MEA. In addition, MEA poisoning by impurity gases were cumulative. After four consecutive poisonings with 1, 3, 5 to 10 ppm, the fuel cell performance of PEMFC was decrease upto 0.54 V(76 %) from 0.71 V.

다관능 아크릴레이트계 자외선 경화형 코팅액의 제조 및 이를 이용한 PET 필름 도막의 광학 특성 연구

이 수(Soo Lee),진석환(Seok Hwan Jin) 한국유화학회 2008 한국응용과학기술학회지 Vol.26 No.4

Ultraviolet curable coating solution was prepared with poly(ethylene glycol) acrylate oligomer and various mono and multi-functional acrylate monomers. The optical properties of UV cured coating layer on PET film with acrylate coating solution containing metal oxides, such as fumed silica and alumina, were also investigated to reduce light reflection on films. Poly(ethylene glycol) diacrylate which has 575 of average molecular weight was used as oligomer acrylate, and pentaerythritol triacrylate and dipentaerythritolpenta-/ hexa acrylate were used as multi-functional acrylate monomers. Also, butyl acrylate was used to improve the adhesion as well as to reduce glass transition temperature to give a better flexability. 1-hydroxy cyclohexyl phenyl ketone was used as photoinitiator. We found out the metal oxides in acrylate coating solution showed a homogeneous dispersion from energy dispersive spectroscopy data. Transmittance and light reflection of coated PET film was measured with UV/vis spectrometer and gloss meter, respectively. When 1.00 g of both metal oxides was added into coating solution, the transmittance and the glossiness were reduced from 90% to 30% and from 190 GU to 35 GU, respectively. However, adding up to 1.00 g of the metal oxide into coating solution did not affect on the hardness of coating layer and adhesion between coated layer and PET film. Conclusively, we can control transmittance and light reflection of coated film by adjusting the amounts of metal oxide in coating solution.

카본 블랙과 천연 고분자를 이용하여 제조한 금속 주조용 이형제의 특성

이수 ( Soo Lee ),진석환 ( Seok Hwan Jin ),박정현 ( Jung Hyun Park ) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

금속 주조시 사용되는 탄소이형제를 카본블랙과 점증제 겸 알데하이드 화합물의 경화제로 사용될 수 있는 수용성 고분자인 잔탄검(X-gum), 카르복시메틸셀룰로오스(CMC)을 혼합하여 제조하였다. 이 때 카본블랙의 안정한 분산을 위하여 0.25 wt%의 X-gum 또는 1.0 wt%의 CMC가 적당하였다. 1.0 wt% 보다 낮은 농도의 CMC를 사용했을 경우 카본블랙이 매우 쉽게 층분리되었다. 유리판에 대한 부착력은 경화제와, 구르탈알데하이드 및 사슬연장제인 올리고당의 양에 비례하였으며. X-gum으로 제조된 탄소 이형제는 CMC를 이용해 제조된 것보다 유리에 대한 부착력이 우수하였다. 결과적으로 본 실험의 최적 조건에서 제조된 탄소이형제는 친환경적으로 주조시에 적용할 수 있을 것으로 판단된다. A die casting mold releasing agent was prepared from aqueous mixture of powdery carbon black and water soluble natural polymeric materials such as xanthan gum(X-gum) and carboxymethyl cellulose(CMC), which were used as thickening agent as well as curing agent with aldehydes. The suitable concentration of natural polymers for stable dispersion of carbon black in water was 0.25 wt% of X-gum or 1.0 wt% of CMC. When CMC was used less than 1 wt%, the final carbon black disperion showed a rapid phase separation. The adhesion of carbon black releasing agent on glass plate was improved with the amount of crosslinking agent, glutaraldehyde and chain extender, oligosaccharide. However, the affinity of carbon black releasing agent prepared with X-gum was stronger than that with CMC on glass plate. The final carbon black mold releasing agents prepared under our mixing conditions can be applied to the production of castings of high quality with good workability and without worthening evironmental situations.

순환전류 전압법을 이용한 이산화황 피독 PEMFC 단위전지의 성능 회복

이수 ( Soo Lee ),진석환 ( Seok Hwan Jin ) 한국유화학회 2011 한국응용과학기술학회지 Vol.28 No.4

Polymer electrolyte membrane fuel cell (PEMFC) performance degrade when sulfur dioxide is present in the fuel hydrogen gas; this is referred as SO2 poisoning. This paper reveals SO2 poisoning on PEMFC cathode part by measuring electrical performance of single cell under 1 ppm and 5 ppm on SO2 gas operating. The security of SO2 poisoning depended on SO2 concentration under the best operating conditions(65℃ of cell temperature and 100% of relative humidity between anode and cathode). SO2 adsorption occured on the surface of catalyst layer on membrane electrode assembly (MEA), In addition, MEA poisoning by SO2 was cumulative but reversible. After poisoning within 5 ppm SO2 for 1hr, the electrical performance of PEMFC was found to recover up to about 93% by cyclic voltametry scan.

저온 충격강도 및 대전방지성 향상을 위한 개질 EPDM을 함유한 polyamide alloy의 제조 및 물성

이수 ( Soo Lee ),진석환 ( Seok Hwan Jin ) 한국유화학회 2011 한국응용과학기술학회지 Vol.28 No.3

Alloys of nylon(PA6) and ethylene.propylene-diene polymer, modified with maleic anhydride(MEPDM) were prepared using a melt kneading process. This study focuses on the effects of the content of MEPDM in PA6 blend on the mechanical and thermal properties of such blends where MEPDM is the dispersed phase. Mechanical properties were examined by stress.strain measurements and impact strength test. Both impact strength of PA6/MEPDM at room temperature and at -20oC were improved up to 400-550% with the amounts of MEPDM. However, PA6/MEPDM containing 3-5 wt% of MEPDM showed the about 700 kgf/m2 of the maximum tensile strength but 8.5 % of the lowest elongation. For certain compositions of PA6 with rubbery MEPDM, the interesting reduction of elongation is caused by the reaction of the polyamide amine end groups with maleic anhydride portion in MEPDM, that provided a reinforcement in the PA6 matrix. In addition, the introduction of antistatic agent on the surface of alloys causes significant reduction of their surface electrostatic resistance.

H2S 피독 고분자 전해질막 연료전지의 연료극 성능 회복 연구

이수(Soo Lee),진석환(Seok-Hwan Jin) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

황화수소가 고분자 전해질막 연료전지의 연료극에 공급되었을 때 전지 성능의 저하와 황화수소 피독 후 순환전류 전압법(CV) 스캔을 통해 전지의 성능 회복에 관한 연구를 수행하였다. 수소에 30 ppm의 황화수소를 희석하여 연료극에 공급하고 전류밀도를 0.5 A/cm2로 고정하여 1시간동안 3차례 피독한 후 CV를 5회 스캔하여 단위전지의 성능회복을 확인한 결과 피독 전 단위전지의 초기 성능은 0.60 V에서 1.16 A/cm2이였으며, 30 ppm의 황화수소를 한 시간 동안 피독한 결과 0.77 A/cm2로 그 성능이 감소하였고, 피독 횟수가 증가함에 따라 성능이 0.57 V까지 감소하였다. 그리고 황화수소 피독 후 각 스텝에서 CV 스캔을 5회 실시하였을 때 단위전지의 성능이 90.3%까지 회복하는 것을 알 수 있었다. 또한, 황화수소 피독 후 단순히 고순도의 수소 가스만 연료극에 주입하여도 약 80% 정도의 성능회복이 가능하였다. 이러한 현상으로 판단할 때 황화수소 가스의 백금 촉매층에의 흡착은 그리 강하지 않음을 알 수 있었다. The recovery of a Pt anode in a PEMFC through 30 ppm H2S/H2 exposure was evaluated by using a cyclic voltametry(CV) scan. First, the PEMFC unit cell performanc loss was measured three times under an anode feeding with 30 ppm H2S/H2 for 1hr at 0.5 A/cm2 of current density. The initial cell performance was 1.16 A/cm2 at 0.6 V without H2S poisoning. After first poisoning step for 1hr the cell performance was decrease to 0.77 A/cm2, and the further poisoning steps decreased up 0.57 V. Finally, the recovery of the cell performance of H2S poisoned PEMFC was achieved up to 90.3% by applying CV scan. Moreover, we also found out that another possible approach for over 80% recovery of the cell performance of H2S poisoned anode Pt catalyst layer was to just inject fresh hydrogen into the anode feeding stream.

알칼리 수용액에서의 화확적 경화를 통한 라이오셀 섬유의 피브릴화 경향 및 염색성에 미치는 영향

이수 ( Soo Lee ),김진우 ( Jin Woo Kim ),진석환 ( Seok Hwan Jin ) 한국유화학회 2010 한국응용과학기술학회지 Vol.27 No.2

황화수소 피독이 고분자전해질 막 연료전지의 성능에 미치는 영향

이수 ( Soo Lee ),진석환 ( Seok Hwan Jin ),김상명 ( Sang Myoung Kim ) 한국유화학회 2011 한국응용과학기술학회지 Vol.28 No.1

Polymer electrolyte membrane fuel cell (PEMFC) performance degrades when hydrogen sulfide (H2S) is present in the fuel hydrogen gas; this is referred to as H2S poisoning. This paper reveals H2S poisoning on PEMFC by measuring electrical performance of single cell FC under various operating conditions. The severity of H2S poisoning depended on H2S concentration under best operating conditions(65˚C of cell temperature and 100% of anode humidification). H2S adsorption occured on the surface of catalyst layer on MEA, but not on the gas diffusion layer(GDL) by analyzing SEM/EDX data. In addition, MEA poisoning by H2S was cumulative but reversible. After poisoning for less than 150 min, performance of PEMFC was recovered up to 80% by just inert nitrogen gas purging.

서로 다른 GDL을 이용한 고분자전해질 막 연료전지의 황불순물 복합피독에 의한 성능 저하

이수 ( Soo Lee ),김재현 ( Jae Hyun Kim ),진석환 ( Seok Hwan Jin ) 한국유화학회 2013 한국응용과학기술학회지 Vol.30 No.1

본 연구에서는 연료극 또는 공기극에 함유된 불순물인 황화합물의 도입을 차단할 수 있는 GDL을 제조하여, 이를 평가용 단위전지에 체결하여 H2S와 SO2를 연료극과 공기극에 각각 동시에 공급하여 PEMFC의 성능 저하 및 회복에 관한 연구를 수행하였다. 그 결과 H2S와 SO2의 농도가 증가함에 따라 전지의 성능이 감소하며 특히 10 ppm 이상의 농도에서는 10분 이내에 약 10-15% 정도 성능이 감소하였다. 특히 GDL 표면의 기공이 없는 CN-2 GDL을 체결한 단위전지의 경우 피독에 의한 성능 감소 속도가 더 빠른 것을 확인하였다. 그리고 단위전지 피독 후 황화합물이 혼합되지 않은 순수 가스를 1시간 이상 공급하였을 때 전지의 성능이 GDL의 종류에 따라 90%에서 95% 이상 회복되며 CN-1 GDL의 경우가 가장 회복이 우수하였다. This paper reveals the performance decrease and recovery of PEMFC when the contaminated fuel gas and air source with sulfur impurities such as hydrogen sulfide and sulfur dioxide were simultaneously introduced to anode and cathode, respectively. Three different GDLs were fabricated with different carbon black and activated carbon to prevent an introduction of sulfur compound impurities into MEA. components. The severity of SO2 and H2S poisoning was depended on concentrations(3 ppm - 10 ppm) of sulfur impurities. Especially, cell performance degradation rate was rapid when MEA fabricated with CN-2 GDL because it had little porosity on GDL surface. Moreover, the cell performance can be recovered up to 90%-95% only with neat hydrogen and fresh air feeding.. Conclusively, MEA fabricated with porous CN-1 GDL showed the best cell performance and recovery efficiency during exposure to poisoning condition by simultaneous sulfur impurities.

알칼리 수용액에서의 화학적 경화를 통한 라이오셀 섬유의 피브릴화 경향 및 염색성에 미치는 영향

이 수(Soo Lee),김진우(Jin Woo Kim),진석환(Seok Hwan Jin) 한국유화학회 2009 한국응용과학기술학회지 Vol.27 No.2

In this research, an effective method for reducing the fibrillation of lyocell fibers, which are spun from a solution of cellulose in N-methyl morpholine-N-oxide(NMMO), through consecutive chemical treatments. Undried solution-spun cellulosic fiber was firstly treated with 10 to 30 wt% of multifunctional crosslinking agents, such as ethylene glycol poly(3-chloro-2-hydroxypropyl) ether, and then dipped into alkaline solution to introduce epoxy functions. Finally steam condition was applied to occur a chemical crosslinking in order to reduce the fibrillation on the surface of fibers. Fibrillation was also reduced significantly by adding extra Na2 SO4 in NaOH solution. In addition, Antifibrilllated lyocell fibers show the slightly higher dyeability(4 %) to Cibacron Blue without serious reduction of mechanical properties.