• 대한화학회지
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• 제55권5호
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• pp.741-745
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• 2011

Well-resolved vibronic emission spectra were recorded in the visible region from the corona discharge of precursor alkylbenzenes in a technique of corona excited supersonic expansion using a pinhole-type glass nozzle. From the observed spectra, we found the evidence of the presence of benzyl-type radicals generated by dissociation of C-C or C-H bonds of alkyl group. After identification of benzyl-type radicals formed in the corona discharge, we suggest that energy densities in alkyl chain play a crucial role in determining the bond dissociation during corona excitation.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.502-506
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• 1999

Different 2-(8,12 dimethyl-5-oxa-7(E), 11-tridecadienyl)-alkyl phenyl ethers, their mono oxirane and thirane derivatives were synthesized and tested on Culex pipiens quinquefasciatus Say for their juvenile hormone activity.

• Mass Spectrometry Letters
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• 제6권3호
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• pp.65-70
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• 2015

N-Alkyl/benzyl substituted isatin derivatives are intermediates and synthetic precursors for the preparation of biological active heterocycles. N-alkyl/benzyl isatins have showed various biological activities, such as cytotoxicity, antiviral, caspase inhibition, cannabinoid receptor 2 agonists for the treatment of neuropathic pain, etc. In this study, N-alkyl/benzyl isatin derivatives were synthesized from isatin and alkyl/benzyl halides in presence of K₂CO₃ in DMF and excellent to quantitative yields (~95%) were obtained. Isatins and benzyl-isatins were condensed with fluorescein hydrazide to form fluorescein hydrazone. All the compounds were subjected to their fragmentation behavior study using LC/MSⁿ. N-Alkyl substituted isatin derivatives fragmented at nitrogen-carbon (N-C) bond, hence gave daughter ion as [RN+H]⁺. Whereas, N-benzyl substituted isatin derivatives fragmented at carbon-carbon (C-C) bond of alkyl chain which linked with nitrogen molecules, therefore gave N-methyl fragments [RNCH₂]⁺. This study demonstrated that, isatin moiety present in a small/large molecule or in a matrix of reaction mixture with/without N-alkyl/benzyl substituents can be identified by mass spectroscopic fragmentation behavior study.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2679-2683
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• 2014

Mechanisms underlying the impacts of interactions between carbon nanoparticles (CNPs) and ionic liquids (ILs) on the physicochemical behavior of CNPs need to be more full worked out. This manuscript describes a theoretical investigation at multiple levels on the interactions of fullerene $C_{60}$ with 21 imidazolium-based ILs of varying alkyl side chain lengths and anionic types and their impacts on $C_{60}$ dispersion behavior. Results show that ${\pi}$-cation interaction contributed to mechanism of the $C_{60}$-IL interaction more than ${\pi}$-anion interaction. The calculated interaction energy ($E_{INT}$) indicates that $C_{60}$ can form stable complex with each IL molecule. Moreover, the direction of charge transfer occurred from IL to $C_{60}$ during the $C_{60}$-IL interaction. Quantitative models were developed to evaluate the self-diffusion coefficient of $C_{60}$ ($D_{fullerene}$) in bulk ILs. Three interpretative molecular descriptors (heat of formation, $E_{INT}$, and charge) that describe the $C_{60}$-IL interactions and the alkyl side chain length were found to be determinants affecting $D_{fullerene}$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.185-188
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• 2005

We synthesized the two types of photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the two types of photopolymer surface can be obtained. The Voltage-transmittance (V-T) curve in the photoaligned TN cell with UV exposure was different from two type. The response time of photoaligned TN cell was measured about 21 ms in two alkyl chain and about 15ms in four alkyl chain.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.469-476
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• 2008

The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of three different types of ionic liquid : quarternary ammonium salt, alkyl pyridinium salt, and alkylimidazolium salt. Ionic liquids of different alkyl groups ($C_3$, $C_4$, $C_6$ and $C_8$) and anions ($Cl^-$, $Br^-$ and $I^-$) were used for the reaction which was carried out in a batch autoclave reactor at $60{\sim}120^{\circ}C$. The catalytic activity was increased with increasing alkyl chain length in the order of $C_3$ < $C_4$ < $C_6$. But the ionic liquid with longer alkyl chain length ($C_8$) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the ionic liquid catalysts, the BGE conversion decreased in the order $Cl^-$ > $Br^-$ > $I^-$.

• 한국응용과학기술학회지
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• 제8권2호
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• pp.145-151
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• 1991

Hazadous properties were evaluated for Alkyl nitrates such as hexyl nitrate, decyl nitrate, dodecyl nitrate and 2-methyl pentyl nitrate, 2-hexyl ethyl nitrate. The thermochemical properties such as heat of vaporization, boiling point, flash point and kinetic parameter for aliphatic nitrate were measured to determine the hazadous properties of these compounds. The boiling points and heat of vaporization increase as the increase of alkyl chain length in alkyl nitrates. Flash point is a linear function of boiling point as same as alkanes. The rate equation in isothermal decomposition are 1/2 order and compensation effect is found between logarithm of frequency factor the activation energy, then the decomposition preceeds with simlar reaction mechanism for each nitrate.

• 한국응용과학기술학회지
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• 제18권2호
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• pp.95-102
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• 2001

Recently, there has been considerably interested in the development to new functional gemini type anionic surfactant, sodium bis-n-alkyl sulfonatosuccinate, had been synthesized through the addition reaction of sodium bisulfite to bis-n-alkyl maleate, in which water was azeotropically distilled by adding benzene to the reaction system, gave a good yield. All the surface activities including krafft point, surface tension, emulsion power and foaming were measure and cmc was evaluated in dilute solution. This results showed a lower ability in $27{\sim}30dyne/cm$ than single-chain surfactant with $32{\sim}35dyne/cm$ to surface tension. Also its cmc value much smaller in $(6.5{\sim}10){\times}10^{-4}mca{\ell}/{\ell}$ than single-chain surfactant with $(40{\sim}45){\times}10^{-4}mca{\ell}/{\ell}$ concentration. In foaming ability and foam stability of gemini surfactant had especially a good ability in approximately $100{\sim}150ml$, and in emulsing power they exhibited a good emulsing phase and stability, and Krafft points were $0{\sim}10^{\circ}C$.

• 공업화학
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• 제22권1호
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• pp.45-47
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• 2011

우수한 항균성능을 가지는 것으로 알려져 있는 N-halamine에 알킬기를 도입하여 페인트용 항균성 물질인 Dichlorohexyl isocyanuric acid (DCHICA)를 합성하였다. 그램 음성균인 E. coli를 사용한 항균테스트, 곰팡이를 이용한 antifungal 테스트를 진행하여 우수한 항균성을 확인하였고, 페인트와의 혼합농도, 시간에 따른 항균성 역시 관찰하였다. 또한, 도입된 알킬기로 인해 도포시에도 우수한 표면항균활성을 가지는 것을 확인하였다.

• 한국해양학회지:바다
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• 제22권2호
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• pp.45-55
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• 2017

Long chain alkyl diols (LCDs)은 다양한 해양 환경 퇴적물에서 관측되고 있다. Rampen et al. (2012)은 해양 표층 퇴적물에서 분석된 LCDs 중 $C_{30}$ 1,15-diol, $C_{28}$ 1,13-diol, $C_{30}$ 1,13-diol를 이용하여 Long chain Diol Index (LDI)라는 고수온 프록시를 제시하였다. 일반적으로 LCDs의 정성 및 정량 분석은 CP-Sil5CB와 DB-5ms 컬럼을 사용해 GC-MS를 주 기반으로 한다. 본 연구에서는 서로 다른 해양환경(동해 및 서북극해)에서 획득한 해양퇴적물을 활용하여 특성이 다른 세가지 GC 컬럼(CP-Sil5CB, HP-5ms, DB-5)이 LCDs의 정량 분석에 미치는 영향을 검토하였다. 본 연구를 통해 일반적으로 CP-Sil5CB로 분석된 농도 결과가 HP-5ms와 DB-5로 분석된 농도 결과와 통계적으로 유의한 차이가 있는 것으로 확인되었다. 하지만 LDI로 복원된 표층수온의 컬럼 간 편차는 동해 퇴적물의 경우 $0.1-0.2^{\circ}C$, 서북극해 퇴적물의 경우 $0.2-0.7^{\circ}C$로 LDI의 calibration error 범위(${\pm}1{\sigma}$) 보다 작았다. 결론적으로 본 연구는 컬럼에 따라 LCDs의 정량 결과는 현저한 차이를 보일 수 있지만, LDI 프록시 값에 미치는 영향은 상대적으로 미비함을 보여 주었다. 따라서 LDI 프록시를 활용한 동해 및 서북극 해양 퇴적물의 고수온 복원에 특성이 다른 컬럼을 사용 할 수 있음을 시사하였다.