• Journal of the Korean Chemical Society
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• v.24 no.6
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• pp.444-451
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• 1980

In order to further elucidate the process of electron solvation in liquids, the medium effect, as the difference between the free energy of $H^+$ in aqueous and non-aqueous states (${\Delta}{\Delta}G_0$), of THF-water mixtures has been investigated. (${\Delta}{\Delta}G_0$) were determined by electromotive force masurements of the cell Pt$H_2Q$, Q, HCI, THF, $H_2O$|KC1 | $Hg_2Cl_2$|Hg(Pt), where $H_2Q$ and Q are hydroquinone and quinone respectively. The effect of dielectric constant on the difference of free energy and the absorption energy of solvated electrons have been studied. For the consideration of these effect the polymerization of water in THF has been studied. Near infrared spectrum of O-H stetching energy has been used to measure the extent of water aggregates. The expermental results indicate that at least in some composition of binary mixtures the electrons or other ions are solvated preferentially with one component of solvents.

• Journal of the Korean Chemical Society
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• v.20 no.5
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• pp.358-363
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• 1976

Kinetic studies on solvolytic reactions of 1-and 2-naphthalene sulfonyl chlorides in ethanol-water mixtures have been carried out by means of conductometry at several temperatures. The rate constant for 2-naphthyl compound was larger than that for 1-naphthyl compound. This was contrary to the prediction of MO theory and could be rationalized as due to the peri-hydrogen effect in the transition state for 1-naphthyl compound. Based on m values of Winstein plots and n values of Kivinen pacolots it was concluded that the solvolytic displacement of the two naphthalene sulfonyl chlorides in ethanol-water mixtures proceed via $S_N2$ process.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.133-133
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.135-135
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.134-134
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• 2003

• Journal of the Korean Chemical Society
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• v.21 no.4
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• pp.262-269
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• 1977

The solvolysis of 1-naphthalene-and 2-naphthalenesulfonyl chlorides in acetone-water mixtures have been studied by means of conductometry. The solvent effect and mechanism have been discussed in terms of variation in solvent composition and activation parameters. The reaction was predominantly $S_N2$ type, but bond breaking increased with the increase of water content. The rate constant for 1-naphthyl compound was smaller than that of 2-naphthyl compound due to the ground state stabilization effect and peri-hydrogen effect, and the latter effect was similar to that in ethanol-water mixtures.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.209-214
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• 2007

Sr hexaaluminate($Sr_{1-x}La_xMnAl_{11}O_{19-\alpha}$) were prepared by sol-gel method of metal alkoxide with 1-butanol or ethylene glycol as a solvent. The physical properties of prepared hexaaluminates were examined by TG/DTA, XRD and $N_2$ adsorption. When ethylene glycol was used as a solvent, the decomposition reaction and dehydroxylation reaction was observed above $400^{\circ}C$ and the temperature of the formation of a crystal structure of hexaaluminate was also increased resulting in small specific surface area and low catalytic activity of methane compared to Sr-hexaaluminate with 1-butanol.

• Journal of the Korean Chemical Society
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• v.30 no.4
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• pp.352-358
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• 1986

An extensive experimental survey on the retention behaviors of phenols in the binary solvent system such as methanol-water, acetonitrile-water and tetrahydrofuran-water as well as the ternary solvent system such as methanol-acetonitrile-water and methanol-tetrahydrofuran-water is presented. A linear equation, which describes the capacity factor as a function of the solvent composition in the mobile phase and is able to predict the retention behaviors of phenols, was obtained. The iso-eluotropic lines for the binary and ternary solvent system are based on the equal strength of the methanol-water solvent which shows an optimum separation of the phenols used. The specific effect of each solute in the binary solvent system appeared to be larger than those in the ternary system.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.112.1-112.1
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• 2011

쌀을 주식으로 하는 우리나라의 여건상 연간 추정치로 싸라기 약 12만톤, 미강 약 49만톤, 왕겨 약 79만톤의 벼 도정 부산물이 발생하고 있다. 본 연구에서는 벼 도정 부산물 중 비식량 자원인 왕겨를 대상으로 고효율 효소 당화를 위한 바이오매스 전처리 방법을 탐색하였다. 왕겨 원시료의 초기 조성은 셀룰로스 34.5%, 헤미셀룰로스 20.5%, 리그닌 25.3%, 회분 14.6%로 나타났는데, 억새 등 초본계 바이오매스와 비교하여 특이하게 높은 성분은 회분으로 이는 벼에 대한 규산질 비료의 시용에서 기인한 것이다. 바이오매스 전처리에 많이 사용되는 암모니아, 희황산 용매와 규산염에 침식성을 가지는 가성소다 용매를 이용하여 각 용매별 단독 및 알칼리-산 복합 처리 하였을 때 효소 가수분해 효율, 고상시료 성분변화 등을 상호 비교하였다. 예비실험을 통하여 암모니아 처리조건은 15%(w/w) $150^{\circ}C$ 20분, 가성소다 처리조건은 1.5%(w/w) $150^{\circ}C$ 20분, 희황산 처리조건은 1.0%(w/w) $150^{\circ}C$ 10분으로 설정하였다. 암모니아 단독, 희황산 단독, 암모니아-희황산 복합 처리 시료의 효소 가수분해 효율은 각각 37.8%, 39.1%, 42.8%로 약 40%선에서 큰 차이가 없었다. 반면 가성소다 단독, 가성소다-희황산 복합 처리시료의 효소 가수분해 효율은 각각 62.7%, 82.8%로 나타나 앞선 3가지 처리방법 대비 50%, 100%에 가까운 효소 가수분해 효율 향상을 보였다. 이 때 전처리 고상시료의 성분 변화를 살펴보면 회분 함량에서 큰 차이를 보였는데 암모니아 단독, 가성소다 단독, 희황산 단독, 암모니아-희황산 복합, 가성소다-희황산 복합 처리에서 각각 47.8%, 77.1%, 43.5%, 55.8%, 94.7%의 회분 성분 기각률(rejection rate)을 나타냈다. 이는 왕겨 효소 가수분해 효율의 최대 저해요인이 회분임을 추정할 수 있다. 왕겨 전처리 알칼리 용매는 암모니아보다 가성소다가 더 효과적이었고 희황산 복합 처리시 그 효과가 크게 상승하였다. 따라서 규산염(회분) 함량이 높은 바이오매스는 고온 고압 조건에서 가성소다 용액으로 처리한 후 그 고상분을 희황산 용액으로 복합 처리하는 시스템이 효소 당화 증진에 매우 유리함을 확인하였다.

• Journal of the Korean Chemical Society
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• v.41 no.2
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• pp.63-68
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• 1997

Calorimetric measurements have been carried out for the binary mixture between protic, ROH (R=Me, Et) and dipolar aprotic solvents, MeCN,$Me_2CO,\;MeNO_2(or EtNO_2)$in order to investigate the molecular interaction and liquid structure of isodielectric solvents. From the measured partial molar enthalpies of the solutions, excess enthalpies for the mixing process were determined. The hydrogen bond strength between two components decreases in the order of$ROH-ROH>ROH-Me_2CO>ROH-MeCN>ROH-MeNO_2(or EtNO_2)$and the hydrogen bond donor acidity decreases in the order of MeOH>EtOH. From this result, we can conclude that the most important interaction for the formation of binary liquid mixture comes from the specific hydrogen bond.