• Carbon letters
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• 제8권4호
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• pp.285-291
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• 2007

Carbon materials of various morphologies were synthesized by pyrolysis of Soap-nut seeds (Sapindus mukorossi), Jack Fruit seeds (Artocarpus heterophyllus), Date-seeds (Phoenix dactylifera), Neem seeds (Azadirachta indica), Tea leaves (Ehretia microphylla), Bamboo stem (Bambusa bambus) and Coconut fiber (Cocos nucifera), without using any catalyst. Carbon materials thus formed were characterized by SEM XRD and Raman. Carbon thus synthesized varied in size (in ${\mu}m$) but all showed highly porous morphology. These carbon materials were utilized as the anode in Lithium secondary battery. Amongst the various precursors, carbon fibers obtained from Soap-nut seeds (Sapindus mukorossi) and Bamboo stem (Bambusa bambus), even after $100^{th}$ cycles, showed the highest capacity of 130.29 mAh/g and 92.74 mAh/g respectively. Morphology, surface areas and porosity of carbon materials obtained from these precursors were analyzed to provide interpretation for their capacity to intercalate lithium. From the Raman studies it is concluded that graphitic nature of carbon materials assist in the intercalation of lithium. Size of cavity (or pore size of channels type structure) present in carbon materials were found to facilitate the intercalation of lithium.

• 공업화학
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• 제28권5호
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• pp.495-500
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• 2017

본 연구에서는 마그네슘 이온 및 (3-aminopropyl)triethoxysilane (APTES)으로 표면에 amine group이 부착된 아미노클레이를 합성(AC)함과 동시에 천연 화합물인 프로폴리스 및 황련 추출물을 클레이 시트 사이에 삽입한 클레이를 합성(PIAC, CIAC)하였다. 주사전자현미경, 입도 분석법, FT-IR, TGA 및 XRD를 통해 클레이의 합성 및 천연 화합물의 삽입을 확인하였고, 특히 XRD data에서 천연 화합물의 삽입에 따른 층간거리(d-space)를 분석함으로써 명확하게 그 특성을 결정하였다. 또한 천연 화합물이 삽입된 클레이인 PIAC 및 CIAC의 경우 삽입되지 않은 아미노클레이(AC)에 비해 항균성이 향상된 것을 최소저해농도(MIC) 분석을 통해 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3658-3662
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• 2010

A new bis-Ru(II) complex, in which two [Ru(1,10-phenanthroline)$_2$dipyrido[3,2-a:2',3'-c]phenazine]$^{2+}$ were tethered by a 1,3-bis(4-pyridyl)propane linker, was synthesized and its binding mode and stoichiometry to DNA was investigated by optical spectroscopy including linear dichroism (LD) and fluorescence intensity measurement. The magnitude of the negatively reduced LD signal of the bis-Ru(II) complex in the dipyrido[3,2-a:2',3'-c]phenazine (DPPZ) ligand absorption region appeared to be similar compared to that in the DNA absorption region, which is considered to be a diagnostic for DPPZ ligand intercalation. The binding stoichiometry measured from its LD magnitude and enhanced fluorescence intensity corresponds to one ligand per three DNA bases, effectively violating the nearest neighbouring site exclusion model for classical DNA intercalation. This observation is in contrast with monomer analogue [Ru(1,10-phenanthroline)$_2$dipyrido[3,2-a:2',3'-c]phenazine]$^{2+}$, which is saturated at the DPPZ ligand to DNA base ratio of 0.25, or one DPPZ ligand per four nucleobases.

• 멤브레인
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• 제15권1호
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• pp.62-69
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• 2005

본 연구에서는 SEBS와 여러 가지의 유기화물로 처리된 MMT (montmorillonite) type의 clay를 이용하여 SEBS-clay 하이브리드 막을 용융삽입법으로 제조하였다. clay의 함량은 5 phr (per hundred resin)로 고정하였다. internal mixer를 사용하여 clay를 SEBS에 분산시켰으며, 제조된 SEBS-clay 하이브리드에서 clay의 특성피크가 완전히 박리되거나 이동하는 XRD 결과로부터 clay의 층간거리가 넓어지는 고분자의 clay 층간삽입을 확인하였다. Clay의 종류에 따라서 제조된 SEBS-clay 하이브리드 막의 가스투과도, 기계적 물성 및 열적 성질을 측정하였다. SEBS-clay 하이브리드 막은 clay 자체의 도입과 층간거리의 확대로 기체분자의 tortuosity를 증가시켜서 가스투과도를 저하시키는 것을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.129.1-129.1
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• 2013

Atomically-thin graphene is the ideal model system for studying nanoscale friction due to its intrinsic two-dimensional anisotropy. Here, we report the reduced nanoscale friction of epitaxial graphene on SiC, investigated with conductive-probe atomic force microscopy/friction force microscopy in ultra-high vacuum. The measured friction on a buffer layer was found to be 1/8 of that on a monolayer of epitaxial graphene. Conductive probe atomic force microscopy revealed a lower conductance on the buffer layer, compared to monolayer graphene. We associate this difference in friction with the difference in total lateral stiffness. Because bending stiffness is associated with flexural phonons in two-dimensional systems, nanoscale frictional energy should primarily dissipate through damping with the softest phonons. We investigated the influence of hydrogen intercalation on the nanoscale friction. We found that the friction decreased significantly after hydrogen intercalation, which is related to loose contact between the graphene and the substrate that results in a lower bending stiffness.

• Journal of Electrochemical Science and Technology
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• 제10권1호
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• pp.55-60
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• 2019

Herein, the effect of counter anions on the formation of a solid electrolyte interphase (SEI) in a propylene carbonate (PC)-based electrolyte solution was investigated. Although the reversible capacities were different, reversible intercalation and de-intercalation of lithium ions occurred in the graphite negative electrode in the PC-based electrolyte solutions containing 1 M $LiClO_4$, $LiPF_6$, $LiBF_4$, and $LiCF_3SO_3$ at low temperature ($-15^{\circ}C$). This indicated that the surface films acted as an effective SEI to suppress further co-intercalation and decomposition reactions at low temperature. However, the SEIs formed at the low temperature were unstable in 1 M $LiPF_6$ and $LiBF_4/PC$ at room temperature ($25^{\circ}C$). On the other hand, increasing reversible capacity was confirmed in the case of $LiCF_3SO_3/PC$ at room temperature, because the SEI formed at the low temperature was still maintained. These results suggest that counter anions are an important factor to consider for the formation of effective SEIs in PC-based electrolyte solutions.

• Bulletin of the Korean Chemical Society
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• 제17권6호
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• pp.547-550
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• 1996

• Bulletin of the Korean Chemical Society
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• 제8권3호
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• pp.220-221
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• 1987

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.96.1-96.1
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• 2000

• 대한화학회지
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• 제58권2호
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• pp.153-159
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• 2014

Herein, the cyclic voltammetric (CV) investigations of structurally similar bisnitrocompounds (N3, N4, N5, N6, having different-$CH_2$-spacer length) is presented. CV study offered interesting interactional possibilities of bisnitrocompounds with chicken blood ds.DNA at physiological pH 4.7 and human body temperature, 310 K. The results indicated strong interaction by these symmetric molecules with ds.DNA and strength of binding is found to depend on length of $CH_2$ spacer group in their molecular structure. Thermodynamics derived from electrochemical binding parameters also favored the irreversible interactions. Moreover, threading intercalation mode of binding is suggested based on thermodynamic and kinetic binding parameters extracted from CV studies.