Anion exchange membrane fuel cells (AEMFCs) have attracted a growing interest as an alternative for proton exchange membrane fuel cells (PEMFCs). AEMs are the most important components of AEMFCs, and it’s a great challenge to attain high ion conductivity, good dimensional, mechanical and alkaline stabilities for AEMs. We prepared poly(ether sulfone ketone)s having various hydrophilic-hydrophobic block ratios, and investigated the effect of the block composition on the chemo-physical properties of the corresponding membranes. The experimental procedures and the properties, including conductivity, morphology and stability will be discussed in detail.

Acute and chronic toxicities of methyl ethyl ketone and methanol were investigated on Paronychiurus kimi (Collembola), for evaluating the potential effects of accidental exposures of these chemical substances on the terrestrial environments. This study was undertaken to establish a toxicity database for these chemical substances, which was required for the preparation of the response compensation and liability act for agricultural production and environmental damage. The 7-d acute toxicity and 28-d chronic toxicity were conducted using the OECD artificial soil spiked with varying, serially diluted concentrations of methyl ethyl ketone and methanol. Mortality was recorded after 7-d and 28-d of exposures, and the number of juveniles were determined after 28-d of exposure in the chronic toxicity test. In both assessments, methanol was more toxic than methyl ethyl ketone in terms of mortality (LC50) and reproduction (EC50). The 7-d LC50 of methyl ethyl ketone and methanol were 762 and 2378 mg kg-1 soil dry wt., respectively, and the 28-d LC50s were 6063 and 1857 mg kg-1 soil dry wt., respectively. The 28-d EC50 of methyl ethyl ketone and methanol were 265 and 602 mg kg-1 soil dry wt., respectively. Comparison of results obtained in this study with literature data revealed that P. kimi was more sensitive to methanol than other soil invertebrates. However, given the high volatility of the chemicals tested in this study, further studies are necessary to improve the current test guideline, or to develop new test guidelines for an accurate assessment of chemicals that require toxicity databases for chemical accidents.

Polymer electrolyte membrane fuel cells (PEMFC) are considered as prospective energy conversion systems because of high efficiency and environmental advantage. However, the current PEMFC technology uses commercialized perfluorosulfonic acid (PFSA) polymers as a proton exchange membrane, which has the issues of high production cost, poor recyclability at intermediate temperature. In this study, We have synthesized a non-fluorinated hydrocarbon membrane. Also, non-fluorinated membrane has a symmetric chemical structure and sulfonated block copolymer was prepared and characterized using 1H-NMR, and the proton conductivity, ion exchange capacity (IEC), and water uptake. properties were evaluated. The synthesis, characteristic and fuel cell performance and newly prepared membrane will be discussed.

본 연구에서는 양이온 교환막으로 Sulfonated poly(ether ether ketone) (SPEEK)를 사용하였고, 음이온 교환막은 poly(vinyl alcohol) (PVA)과 poly(vinyl amine) (PVAm)을 혼합하여 가교시킨 막을 이용하였으며, 이에 대한 막결합형 축전식 탈염 공정(Membrane capacitive deionization, MCDI)의 성능실험을 진행하였다. 음이온 교환막의 함수율, 이온교환용량, FT-IR 측정을 통하여 막의 특성을 알아보았다. 음이온 교환막의 가교 시간이 3 h에서 5 h으로 증가할수록 염 제거 효율은 81.3%에서 65.7, 53.8%로 감소하였다. PVAm의 농도를 40, 60, 80%로 달리하여 실험한 결과 염 제거 효율은 81.3, 75.2, 37.7%로 PVAm이 80% 함량일 때 가장 효율이 떨어졌다. 이는 음이온 교환막의 가교 시간과 PVAm의 농도가 염제거 성능에 영향을 미치는 것으로 사료된다.

Branched sulfonated poly(ether sulfone-ketone) copolymer was prepared with bisphenol A, 4,4-difluorobenzophenone, sulfonated chlorophenyl sulfone (40mole% of bisphenol A) and THPE (1,1,1-tris-p-hydroxyphenylethane). THPE was used 0.4 mol% of bisphenol A to synthesize branched copolymers. Organic-inorganic nano composite membranes were prepared with copolymer and a series of nanoparticles (20 nm, 4, 7 and 10 wt%). The composite membranes were cast from dimethylsulfoxide solutions. The films were converted from the salt to acid forms with dilute hydrochloric acid. The membranes were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. Branched copolymer and nano composite membranes exhibit proton conductivities from to , water uptake from 52.9 to 62.4%, IEC from 0.81 to 1.21 meq/g and methanol diffusion coefficients from to .

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 . Organic-inorganic composite membranes were obtained by mixing organic polymers with hydrophilic (ca. 20nm) obtained by sol-gel process. The polymer and a series of composite membranes were studied by FT-IR, , differential scanning calorimetry (DSC) and thermal stability. The proton conductivity as a function of temperature decreased as 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 , and low affinity towards methanol .

투과 증발은 막을 근거로 한 에너지 절약형 분리공정으로서 전통적인 증류 분리공정과 비교하여 높은 선택도를 나타내기 때문에 액상 혼합물 분리에 대체 공정으로서 주목받고 있다. 투과 증발에 이용되는 분리막으로서 제올라이트 분리막은 고분자 분리막보다 열적, 기계적, 화학적 안정성이 우수하며 특히 silicalite-1 분리막은 큰 소수성을 나타내기 때문에 유기화합물을 수용액으로부터 효과적으로 분리할 수 있다. 본 연구에서는 silicalite-1 분리막을 이용한 투과 증발 실험을 통하여 케톤계 휘발성 유기화합물을 분리하였다. 아세톤과 MEK의 공급 농도가 증가함에 따라 아세톤과 MEK의 투과 플럭스는 증가하였으며 선택도는 감소함을 관찰할 수 있었다.

Poly(ether ether ketone)(PEEK)를 황산을 사용하여 설폰화시킨 후 폴리설폰과 다양한 조성으로 혼합하여 블렌드 고분자 전해질 막을 제조하였고 조성의 변화에 따른 메탄을 투과도, 수소이온전도도, 그리고 이온교환용량의 변화를 측정하였다. 폴리설폰의 경우 이온전도도는 낮은 반면에 메탄올에 대한 저항은 우수하였다. 그러나, 설폰화된 PEEK의 양이 증가함에 따라 메탄을 투과도와 수소이온전도도가 함께 증가하였다. 이온전도도와 메탄을 투과도의 비로부터 폴리설폰의 양이 20%일 때 가장 좋은 선택성을 가지는 것을 알 수 있었다.

The reactions of semicarbazide hydrochloride with aliphatic and alicyclic ketones were studied kinetically at 15, 25, 35 and 45℃ in 20% ethanol solution buffered at pH 2.9. The rate of cyclohexanone semicarbazone formation is 5.5 times as fast as that of cyclopentanone semicarbazone, while 3-pentanone semicarbazone is 4.7 times as slow as that of 2-pentanone, The activation energy of cyclohexanone, 2-pentanone, 2 hexanone, cyclopentanone, 4-methyl-2-pentanone and 3-pentanone semicarbazone formation are calculated 5.08, 7.52, 8.79, 9.59, 9.49, 11.59, respectively. It is concluded from the effect of ionic strength that the reaction is affected by not ion but neutral molecules being progressed hydrogen bond between oxygen atom of carbonyl group and hydrogen atom of acid-catalyst and concerted nucleophilic attack of free base on the carbonly compound. Dependence on pH of the rate of 2-pentanone semicarbozone formation is linear relationship below pH 4.60 and above pH 5.60. As a result of studing citric acid catalysis, second order constants increase linearly with citric acid concentration. As the catalyst concentration is varied from 0.025 to 0.10 mol/1 at pH 2.90, the rate constants increase 1.4 times, but slight increase is observed at pH 5.60. Conclusively, the rate-determining step is formation of tetrahedral interemediate below pH 4.65 and dehydration between pH 5.60 and pH 7.11. It is concluded that the formation reaction of cyclohexanone semicarbazone is faster than cyclopentanone semicarbazone due to the steric strain in the process of forming tetrahedral intermediate.

Perilla frutescens (L.) is an annual herbaceous and ornamental plant in the Lamiaceae family. Perilla frutescens (L.) Britt.cv.Chookyoupjaso were irradiated using a 200 Gy gamma ray in 1995. By HPLC analysis, this new cultivar significantly induced isoegomaketone content compared with ‘Chookyoupjaso’ control. The phenotypical difference was the changed leaf color of the ‘Atom-Ketone’ from violet to green. The yield potential of this cultivar (106 kg/10a) was 1.83 folds higher than that of ‘Chookyoupjaso’ (57.65 kg/10a). The methanol extracts of ‘Atom-Ketone’ inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. This extract was further partitioned using ethyl acetate (EtOAc), butanol (BuOH), and water. The EtOAc fraction (EF-Atom-Ketone) was evaluated for antiinflammatory activities. These results indicated that the EF-Atom-Ketone reduced NO production by inhibiting inducible nitric oxide synthase (iNOS) expression. The EF-Atom-Ketone treatment also significantly diminished expression of MCP-1 and IL-6. Therefore, ‘Atom-Ketone’ reveals the potential therapeutic use of bioactive

The photocatalytic decomposition characteristics of single n-pentane, n-pentane mixed with methyl ethyl ketone (MEK), and n-pentane mixed with ethyl acetate (EA) by cylindrical UV reactor installed with TiO2-coated perforated plane were studied. The effects of the residence time, the inlet gas concentration, and the oxygen concentration were investigated. The removal efficiency of n-pentane was increased with increasing the residence time and the oxygen concentration, but decreased with increasing the inlet concentration of n-pentane. The photocatalytic decomposition rates of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA fitted well on Langmuir-Hinshelwood kinetics equation. The maximum elimination capacities of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA were obtained to be 465 g/m3․day, 217 g/m3․day, and 320 g/m3․day, respectively. The presence of coexisting MEK and EA vapor had a negative effect on the photocatalytic decomposition of n-pentane and the negative effect of MEK was higher than that of EA.

Unlike many laboratory-scale studies on absorption of organic compounds (VOCs), limited pilot-scale studies have been reported. Accordingly, the present study was carried out to examine operation parameters for the effective control of a hydrophilic VOC (methyl ethyl ketone, MEK) by applying a circular pilot-scale packed-absorption system (inside diameter 37 cm × height 167 cm). The absorption efficiencies of MEK were investigated for three major operation parameters: input concentration, water flow rate, and ratio of gas flow-rate to washing water amount (water-to-gas ratio). The experimental set-up comprised of the flow control system, generation system, recirculation system, packed-absorption system, and outlet system. For three MEK input concentrations (300, 350, and 750 ppm), absorption efficiencies approached near 95% and then, decreased gradually as the operation time increased, thereby suggesting a non-steady state condition. Under these conditions, higher absorption efficiencies were shown for lower input concentration conditions, which were consistent with those of laboratory-scale studies. However, a steady state condition occurred for two input concentration conditions (100 and 200 ppm), and the difference in absorption efficiencies between these two conditions were insignificant. As supported by an established gas-liquid absorption theory, a higher water flow rate exhibited a greater absorption efficiency. Moreover, as same with the laboratory-scale studies, the absorption efficiencies increased as water-to-gas ratios increased. Meanwhile, regardless of water flow rates or water-to-gas ratios, as the operation time of the absorption became longer, the pH of water increased, but the elevation extent was not substantial (maximum pH difference, 1.1).