• 전기화학회지
• /
• 제2권4호
• /
• pp.183-189
• /
• 1999

원자력 시설의 가동 및 유지보수 중에 중$\cdot$저준위 방사성폐기물로 다량 생성되는 폐 유기이온교환수지를 상온의 수용 상 내에서 분해 처리하는 공정을 개발할 목적으로, 전기화학적으로 생성되는 Ag(II)를 매개산화제로 사용하여 양이온 및 음이온교환수지의 분해 연구를 수행하였다. Ag(II) 매개산화 공정에서 제어 가능한 인자인 전류, 온도 및 전해질 농도가 이온교환수지의 분해거동에 미치는 영향을 고찰하였다. 양이온교환수지는 거의 대부분 $CO_2$로 분해되었으며, 전류밀도가 감소할수록 전류효율이 증가됨을 보인 반면에 양극전해질로 사용된 질산의 농도 및 온도가 증가하더라도 분해거동에는 영향을 미치지 않았다. 양이온교환수지와는 달리 음이온교환수지의 분해시에는 온도와 무관하게 약 $10\%$ 정도가 CO로 분해되었고, $CO_2$로의 분해효율은 온도에 의존하는 경향을 보였으며, $60^{\circ}C$ 이상에서 효과적으로 분해가 가능하였다.

• 한국응용과학기술학회지
• /
• 제38권3호
• /
• pp.903-913
• /
• 2021

본 연구에서는 싸이크론 헥산에서 PVC와 트리에틸디아민 (TEDA), 1,4-디메틸피페라진(DMP) 및 1,4-비스(이미다졸-1-일메틸)벤젠을 각각 치환반응시켜서3가지 형태의 PVC 멤브레인, AEM-1, AEM-2, and AEM-3를 제조하였다. AEM-1, AEM-2, and AEM-3멤브레인의 성공적인 제조 여부를 이온전도도(S/cm), 물함수율 (%), 접촉각, 이온교환능력 (m_eq/g), 열분석, SEM 및 XPS 분석 통하여 확인하였다. 또한, 제조된 가교 음이온 PVC멤브레인을 사용하여 유기전해질에서 전기화학 캐퍼시터 실험을 수행한 결과, 제조된 AEM-1, AEM-2 AEM-3 멤브레인의 경우 유기전해질에서 충/방전실험결과 매우 안정적임을 확인 할 수 있었다. 이러한 결과로 치환반응 후에 용매 캐시팅법으로 제조된 PVC기반 멤브레인 (AEM-1, AEM-2, 및 AEM-3)의 경우 유기전기화학캐퍼시터 (슈퍼캐퍼시터)용 분리막으로 사용될 수 있다.

• Macromolecular Research
• /
• 제14권3호
• /
• pp.287-299
• /
• 2006

To successively synthesize star-branched polymers, we developed a new iterative methodology which involves only two sets of the reactions in each iterative process: (a) an addition reaction of DPE or DPE-functionalized polymer to a living anionic polymer, and (b) an in-situ reaction of 1-(4-(4-bromobutyl)phenyl)-1-phenylethylene with the generated 1,1-diphenylalkyl anion to introduce one DPE functionality. With this methodology, 3-, 4-, and 5-arm, regular star-branched polystyrenes, as well as 3-arm ABC, 4-arm ABCD, and a new 5-arm ABCDE, asymmetric star-branched polymers, were successively synthesized. The A, B, C, D, and E arm segments were poly(4-trimethylsilylstyrene), poly(4-methoxystyrene), poly(4-methylstyrene), polystyrene, and poly(4-tert-butyldimethylsilyloxystyrene), respectively. All of the resulting star-branched polymers were well-defined in architecture and precisely controlled in chain length, as confirmed by SEC, $^1H$ NMR, VPO, and SLS analyses. Furthermore, we extended the iterative methodology by the use of a new functionalized DPE derivative, 1-(3-chloromethylphenyl)-1-((3-(1-phonyletheny1)phenyl) ethylene, capable of introducing two DPE functionalities via one DPE anion reaction site in the reaction (b). The number of arm segments of the star-branched polymer synthesized by the methodology could be dramatically increased to 2, 6, and up to 14 by repeating the iterative process.

• Bulletin of the Korean Chemical Society
• /
• 제27권10호
• /
• pp.1587-1592
• /
• 2006

We report the preparation, structure and magnetic properties of a new pillared complex, copper(II) hydroxy-1,4-butanedisulfonate, $Cu_2(OH)_3(O_3SC_4H_8SO_3)_{1/2}$. The titled compound was obtained by anion exchange, using copper hydroxyl nitrate $(Cu_2(OH)_3NO_3)$ as the starting material. According to the XRD data, this compound exhibits a pillared layered structure with organic layers tilted between the copper hydroxide layers with a tilt angle of $21.8^{\circ}$. FTIR spectroscopy confirms total exchange of nitrate by the sulfonate and indicates that the sulfonate functions are linked to the copper(II) ions with each aliphatic chain bridging the adjacent hydroxide layers. According to the dc and ac magnetic measurements, the title compound is a metamagnet consisting of spin-canted antiferromagnetic layers, with a Neel temperature of 11.8 K.

• 약학회지
• /
• 제34권2호
• /
• pp.112-116
• /
• 1990

8-Acyl-2-hydroxyphenzaine -5, 10-dioxides and 8-acyl-2-aminophenazine-5, 10-dioxides bearing n-butanoyl, n-hexanoyl and n-octanoyl groups were synthesized. It was attempted to observe the effect of phenazine dioxide derivatives on the hepatic xanthine oxidase activity in this study. As the activity of xanthine oxidase, the key enzyme in the generation of superoxide anion radical ($O_2$), was measured in the presence of phenazine dioxide derivatives, the action of 8-acyl-2-hydroxyphenazine-5,10-dioxide derivatives inhibited with increase of numbers of carbon atom bearing 8-acyl group. Moreover, when plotted on double reciprocal form, the Vmax value decrease as increase of numbers of carbon atom bearing acyl groups without affecting the Km value. However, the hepatic xanthine oxidase activity was not changed by 8-acyl-2-aminophenazine-5,10-dioxide derivatives.

• Bulletin of the Korean Chemical Society
• /
• 제32권1호
• /
• pp.71-76
• /
• 2011

An efficient nucleophilic [$^{18}F$]fluorination has been studied to reduce byproducts and preparation time. Instead of conventional aqueous solution of $K_2CO_3-K_{222}$, several organic solution containing inert organic salts were used to release [$^{18}F$]fluoride ion and anion bases captured in the polymer cartridge, concluding that methanol solution is the best choice. Comparing to azeotropic drying process, one min was sufficient to remove methanol completely, resulting in about 10% radioactivity saving by reducing drying time. The polymer cartridge, Chromafix$^{(R)}$ (PS-$HCO_3$) was pretreated with several anion bases to displace pre-loaded bicarbonate base. Phosphate bases showed better results than carbonate bases in terms of lower basicity. tert-Butanol solvent used as a reaction media played another critical role in nucleophilic [18F]fluorination by suppressing eliminated side product. Consequent [$^{18}F$]fluorination under the present condition afforded fast preparation of reaction solution and high radiochemical yields (98% radio-TLC, 84% RCY) with 94% of precursor remained.

• The Korean Journal of Physiology
• /
• 제22권1호
• /
• pp.55-62
• /
• 1988

가토 신피질 절편에서 p-aminohippurate (PAH) 이동에 대한 카드뮴 이온(Cd)의 영향을 조사하여 다음과 같은 결과를 얻었다. 조직절편과 용액내의 PAH 농도비(S/M PAH)는 용액내에 Cd이 0.1 mM이상 존재할 때에 현저히 감소되었다. PAH influx에 대한 동력학적 분석결과 Cd에 의하여 influx의 최대이동율(즉 $V_{max}$)은 심하게 감소되지만 운반체와 기질간의 친화력(즉 $K_{m}$)에는 변화가 없었으며, 수동적 influx 역시 변화되지 않았다. 신피질조직의 산소 소모율은 1 mM Cd에 의하여 35% 가량 억제되었으며, 신피질 microsome 분획의 Na-K-ATPase 활성도는 Cd 농도가 $10^{-7}M$ 이상일 때 의의있게 억제되었다. 이상의 결과로 미루어 볼 때 신장조직이 카드뮴이온에 직접 노출될 경우 유기음이온의 능동적 이동능이 심하게 저해된다고 사료된다.

• 한국수소및신에너지학회논문집
• /
• 제33권1호
• /
• pp.19-27
• /
• 2022

A series of QPAE/TiO₂-x (x = 1, 4, 7 and 10 wt%) organic/inorganic composite membranes were prepared as electrolyte membranes for alkaline anion exchange membrane fuel cells by controlling the content of inorganic filler with quaternized poly(arylene ether) (QPAE) random copolymer. Among the prepared QPAE/TiO₂-x organic/inorganic composite membranes, the highest ionic conductivity was 26.6 mS cm^-1 at 30℃ in QPAE/TiO₂-7 composite membrane, which was improvement over the ionic conductivity value of 6.4 mS cm^-1 (at 30℃) of the pristine QPAE membrane. Furthermore, the water uptake, swelling ratio, ionic exchange capacity, and thermal property of QPAE/TiO₂-x composite membranes were improved compared to the pristine QPAE membrane. The results of these studies suggest that the fabricated QPAE/TiO₂-x composite membranes have good prospects for alkaline anion exchange membrane fuel cell applications.

• Journal of Photoscience
• /
• 제9권2호
• /
• pp.412-414
• /
• 2002

Several peroxovanadium(V) complexes with an organic chelate ligand decompose spontaneously, depending on the nature of the chelate ligand. The self-decomposition reactions of the dinuclear peroxovanadium(V) complex with 2-oxo-l,3-diaminopropane-N,N,N',N'-tetraacetate (dpot) and the peroxovanadium(V) complexes with N-carboxymethylhistidinate (cmhist) and histamine-N,N-diacetate (histada) accompany the reduction of vanadium(V) to vanadium(IV). This implies that the peroxide anion acts as a reducing agent and thus the peroxide is oxidized in the decomposition process of the peroxovanadium(V) complexes. The oxidized dioxygen species have been characterized spectrophotometrically. Superoxide anion has been detected in 2-3 % yields using the reduction of cytochrome c method and chemiluminescence method utilized MCLA as a fluorescer. Singlet oxygen has also been detected in higher yields on the basis of chemiluminescence of tryptophan.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
• /
• pp.77-80
• /
• 1995

Enhancing the electrical conductivity of the ultrathin organic films using Langmuir-Blodget technique is important step for the developement of molecular electronic device. The Octadecylviologen-TCNQ was synthesized with Octadecylviologen-Bromide an Lithium TCNQ Sine Octadecylviologen-TCNQ has two TCNQ snion radicals, the conductivity of LB film is expected to increase. The $\pi$-A isotherm showed that the limiting area was 150${\AA}$$\^$2/ molecule and the silid-like transition surface pressure was 25 mN/m. The electronic transition of the TNCNQ anion radical was observed at 400 nm. Intermolecular charge transfer absorption was observed at 600nm and 850~1050 nm which ay resulted from the TCNQ anion radical dimer formation. The electrical conductivity of the viologen -TCNQ LB film was 10$\^$-6/cm This values was 100 times higher than that of the quinolinium-TCNQ and pyridinium-TCNQ LB films.