• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.660-662
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• 2005

본 연구에서는 미 인근 해저에서 ODP로 확인된 부존 하이드레이트 샘플을 다양한 분광학 및 실험적 분석 방법을 통해 시료의 물성 및 특성을 파악하여 부존된 하이드레이트 자원의 성분 파악을 목적으로 하고 있다. 일반적으로 가스 하이드레이트 연구에 있어서 X-ray diffractometer, NMR stectrometer, Raman spectrometer 등 분광학적 분석기기를 이용하여 가스 하이드레이트의 구조 및 성분을 규명한다. 본 연구에서는 실험실에서 인위적으로 만들어진 메탄 하이드레이트와 심해저 천연가스 하이드레이트 층에서 채취된 샘플의 비교 분석을 통하여 심해에 매장되어 있는 천연가스 하이드레이트의 구조 및 성분을 규명하였다 XRD 결과로부터 천연가스 하이드레이트는 sI의 구조를 가지며 NMR 및 Raman 결과에 의하면 하이드레이트 내에 포집되어 있는 가스의 주 성분은 메탄인 것으로 밝혀졌다. 또한 천연가스 하이드레이트를 이용한 이산화탄소의 치환 실험을 통하여 심해저 천연가스 하이드레이트 층의 이산화탄소 저장 매체로의 활용 가능성을 조사하였다.

• Magazine of the Korea Concrete Institute
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• v.5 no.2
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• pp.121-128
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• 1993

나프탈렌 또는 나프톨을 황산화하고 포름알데히드와 축합 반응시켜 나프탈렌 축합물 및 나프톨 축합물을 합성하였다. 또한, 나프탈렌과 나프톨을 모두 함유하는 공축합물도 합성하였다. 이들 축합물의 확인은 핵자기공명스텍트럼, 적외분광스펙트럼, 자외분광스펙트럼으로 행하였다. 한편 이들 축합물들의 시멘트에 대한 분산성을 예측하기 위하여 시멘트 표면에의 흡착실험을 행하였다. 그 결과 수산기를 함유하는 나프톨 축합물(TSC)>나프탈렌-나프톨공축합물(NSS)의 순으로 시멘트에 대한 흡착율이 증가했다. 위의 결과들로부터 주쇄(main chain)에 나프톨을 함유하는 합성축합물(TCS, NT5)은 시멘트분산제로서의 가능성이 시사되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.517-517
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• 2013

세포막지질의 산화는 심각한 세포막의 기능저하를 유발하고 심하면 세포를 죽음에 이르게하여 생물학적으로 중요한 지표이다. 세포막지질의 산화는 간접적인 화학적 방법으로 측정하거나, 지질을 추출해내어 질량분석기나 핵자기공명분광기 같은 물리적 방법으로 분석한다. 우리는 이온유도 이차전자 방출계수(${\gamma}$) 변화를 측정하여 세포막지질의 산화를 지질추출 없이 측정할 수 있는지 조사해 보았다. 세포막분리가 쉬운 적혈구를 모델세포로 사용하였고, 다양한 라디칼을 발생시키는 대기압 공기 DBD플라즈마 장치를 이용하였다. 적혈구를 플라즈마에 노출하는 시간으로 산화의 정도에 차이를 만들어 측정값과 비교하였다. ${\gamma}$값은 Auger의 중화이론에 바탕을 둔 이온유도 이차전자 방출빔(${\gamma}$-FIB)장비를 이용하여 측정하였다. 측정결과 적혈구가 산화됨에 따라서 ${\gamma}$값이 증가함을 볼 수 있었고, 동시에 workfunction값이 변화함을 보았으며, 그 결과를 화학적 방법과 비교해 보았다.

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.536-542
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• 1988

A nickel(Ⅱ) complex, Ni(IAA-NBz) (IAA-NBz') with ligand, N-benzylisonitrosoacetyl acetone imine (H-IAA-NBz) has been synthesized. This complex is very stable at room temperature and has cis-form and trans-form isomers. The ratio of nickel (Ⅱ) ion and ligand combined is 1 : 2. The elemental analysis, ir, nmr. electronic spectra and mass spectra have been studied. It is suggested from these studies that the isonitroso group of one ligand, H-IAA-NBz coordinates to nickel(Ⅱ)ion through the nitrogen atom to form five-membered ring, while that of the other ligand, H-IAA-NBz coordinates to nickel (Ⅱ) ion through the oxygen atom to form six-membered ring in square-planar complex.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.694-696
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• 2010

We have synthesized boron (or phosphorous) doped silicon nanoparticles (Si-NPs) by a solution process. The surfaces of the Si-NPs were terminated with various alkyl groups to form a protecting layer. The Si-NPs were characterized by UV-Vis, PL, FTIR, and NMR. Through a microwave sintering process, the crystalline thin films of the Si-NPs were prepared by removing the surface alkyl groups. The TEM and SEM images reveal that contiguous films as large as $200{\mu}m$ in diameter were formed with a cubic structure. The electrical conductivity of the Si film was controlled by a doping type.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.277-282
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• 2021

Two hydrophobic imidazolium based ionic liquids including 1-benzyl-3-butylimidazolium hexafluorophosphate [BzBIM]PF₆ and 1-pentyl-3-butylimidazolium hexafluorophosphate [PBIM]PF₆ having the same anion and different cation parts were synthesized. The structural composition of these ionic liquids were confirmed with Fourier-transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). Their physiochemical properties such as viscosity, ionic conductivity and thermal stability alongside electrochemical potential window range for both ionic liquid electrolytes were characterized and compared to each other. The overall results revealed that [BzBIM]PF₆ has higher thermal and electrochemical stabilities and viscosity than that of [PBIM]PF₆ probably due to the presence of benzyl ring in the imidazolium cation providing strong intermolecular π-π interactions.

• Polymer(Korea)
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• v.26 no.3
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• pp.293-299
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• 2002

By the reaction of m-cresol as a microbicide with acryloyl chloride m-cresyl acrylate (CA) was synthesized, and polymers with the moiety of m-cresol were prepared by the radical terpolymerization of CA -methylmethacrylate -acrylic acid. The contents of CA unit in the polymers were found to be 4.7 mol% and 10.1 mol% from their nuclear magnetic resonance spectra. The number -average molecular weights of the polymers were in the range of 12000 to 15000. Through the hydrolysis of the polymers m-cresol was released. The release rate of the microbicide increased with increasing PH of the release medium. This result can be attributed to enhanced proton dissociation of carboxyl group of the acrylic acid unit in the polymers. These polymers showed microbicidal activities for S. aureus as a positive microbe and E. coli as a negative microbe.

• Journal of the Korean Magnetics Society
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• v.4 no.2
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• pp.184-187
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• 1994

Nuclear magnetic resonance of $^{133}Cs$ in a $CsMnCl_{3}$ single crystal grown by the Czochralski method has been investigated by employing a Bruker FT NMR spectrometer. The $^{133}Cs$ resonance of two different groups were recorded. Various transitions belonging to two cesium spectra of a different intensity ratio are analyzed. The quadrupole coupling constant of Cs(I) is $0.15{\pm}0.01$ MHz, and that of Cs(II) is $0.21{\pm}0.01$ MHz. The anisotropy parameter is zero for both. The principal axes of the EFG tensors for these two sites are found to be the same. The Z axis, conventionally the largest component of the EFG tensor, is parallel to the crystallographic c-axis.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.43-48
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• 1993

The $^1H-NMR$ spectra of the NH-group were obtained for N-ethylacetamide (NEAA) in the series of n-alcohols over a temperature range of 310∼350K by using NMR spectroscopy. The $^1H-NMR$ lineshape coupled to $^{14}N$ nucleus were analyzed to obtain the reorientational correlation times ${\tau}_c$ of NEAA. The data indicate that the coupling of solute and solvent decreases as the chain length of n-alcohols increases. But in the n-alcohols the reorientational motion depends almost linearly on η/T of solvents over our temperature range. The results are discussed in the context of the subslip phenomenon.

• Elastomers and Composites
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• v.41 no.2
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• pp.108-115
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• 2006

A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4'-Bis(9-hydroxynonoxy)biphenyl (BP9). 4,4'-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane. Structures of the monomer and the corresponding polymers were identified using FT-IR and $^1H-NMR$ spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy.