• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3233-3240
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• 2012

We demonstrated the combined applications of online protein digestion using trypsin immobilized enzyme reactor (IMER) and dual tandem mass spectrometry with collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) for tryptic peptides eluted through the trypsin-IMER. For the trypsin-IMER, the organic and inorganic hybrid monolithic material was used. By employing the trypsin-IMER, the long digestion time could be saved with little or no sacrifice of the digestion efficiency, which was demonstrated for standard protein samples. For three model proteins (cytochrome c, carbonic anhydrase, and bovine serum albumin), the tryptic peptides digested by the IMER were analyzed using LC-MS/MS with the dual application of CAD and ETD. As previously shown by others, the dual application of CAD and ETD increased the sequence coverage in comparison with CAD application only. In particular, ETD was very useful for the analysis of highly-protontated peptide cations, e.g., ${\geq}3+$. The combination approach provided the advantages of both trypsin-IMER and CAD/ETD dual tandem mass spectrometry applications, which are rapid digestion (i.e., 10 min), good digestion efficiency, online coupling of trypsin-IMER and liquid chromatography, and high sequence coverage.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.67.1-67.1
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• 2012

Graphene has attracted much attention for future nanoelectronics due to its superior electrical properties. Owing to its extremely high carrier mobility and controllable carrier density, graphene is a promising material for practical applications, particularly as a channel layer of high-speed FET. Furthermore, the planar form of graphene is compatible with the conventional top-down CMOS fabrication processes and large-scale synthesis by chemical vapor deposition (CVD) process is also feasible. Despite these promising characteristics of graphene, much work must still be done in order to successfully develop graphene FET. One of the key issues is the process technique for gate dielectric formation because the channel mobility of graphene FET is drastically affected by the gate dielectric interface quality. Formation of high quality gate dielectric on graphene is still a challenging. Dirac voltage, the charge neutral point of the device, also strongly depends on gate dielectrics. Another performance killer in graphene FET is source/drain contact resistance, as the contact resistant between metal and graphene S/D is usually one order of magnitude higher than that between metal and silicon S/D. In this presentation, the key issues on graphene-based FET, including organic-inorganic hybrid gate dielectric formation, controlling of Dirac voltage, reduction of source/drain contact resistance, device structure optimization, graphene gate electrode for improvement of gate dielectric reliability, and CVD graphene transfer process issues are addressed.

• 대한화학회지
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• 제42권4호
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• pp.487-500
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• 1998

A bird's-eye view on preparation, structure and properties of polymeric complexes in the field of Inorganic-Organic-Hybrids is presented in the view point of solid state and materials chemistry. These materials are useful precursors for preparing nanoparticles and fine grain oxides. Some of them are electroactive and are used as protonic or lithium electrolytes, electrochromic materials or membranes for sensors and actuators. New results on bio-hybrids, a class of material not far from polymeric complexes, are also described.

• 한국안전학회지
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• 제24권6호
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• pp.63-71
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• 2009

In order to improve flame retardancy, the halogen free organic melamine phosphate(M-P) flame retardant was synthesized from melamine and phosphoric acid by the reaction of precipitation. The ignition test was carried out preparing hybrid flame retardant compound($H_bFRC$) consisting of organic M-P and inorganic Mg$(OH)_2$ as a flame retardant in the polyolefin resins. The flame retardancy and mechanical properties of flame retardant aluminum composite panel($H_bFRC$-ACP) were performed to investigate the possibility of the composite material, which was contained M-P, as a inner core for $H_bFRC$-ACP. For this study, the results of ignition test indicate that a char formation and drip suppressing effect, and combustion time reduced as the content of M-P increased. The limited oxygen index(LOI) values were measured 17.4vol% and 31.5vol% for LDPE only and $H_bFRC$-3(M-P content: 15wt%), respectively. And it was verified that the $H_bFRC$-3 was needed more oxygen quantity with the increase of M-P content when it combustion. Also, the results from thermogravimetric analysis were observed endothermic peak at $350^{\circ}C$ and $550^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by the mixture of M-P and Mg$(OH)_2$. The LDPE-ACP (using only LDPE as a inner core), $35.13kW/m^2$ of heat release rate(HRR) and 13.43MJ/m2 of total heat release(THR) were measured while the $H_bFRC$-ACP, $10.44kW/m^2$ of HRR and 1.84MJ/m2 of THR were measured by results of cone calorimeter test. In case of $H_bFRC$-ACP, the average gas emission amount of CO and $CO_2$ could be decreased down to 25% and 20%, respectively, in comparison with LDPE-ACP. The mechanical properties such as tensile strength, bending strength and adhesion strength of $H_bFRC$-ACP were revealed slightly high values $54N/mm^2$, $152N/mm^2$ and 120N/25mm, respectively, compared with LDPE-ACP. It was confirmed that flame retardancy was improved with the synergy effect because of char formation by M-P and hydrolysis by Mg$(OH)_2$. The result of this study suggest that $H_bFRC$ can be applied for an adequate halogen free flame retardant composite material as a inner core for ACP.

• 한국산학기술학회논문지
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• 제9권5호
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• pp.1354-1358
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• 2008

본 연구에서는 EU의 6대 유해물질(Pb, Hg, Cd, $C^{+6}$, PBB/PBDE) 규제와 국내 환경부의 환경유해물질 규제법규에 대응할 수 있는 친환경 무독성 난연 도료를 개발하였다. 개발한 도료는 VOC(휘발성유기화합물) 배출이 적어 친환경적이며, 할로겐계를 탈피하여 인체안전성 확보됨과 동시에 검정기술기준(KOFEIS 0201)에 적합한 수용성 유 무기계 복합화합물이다. 유 무기계 난연 복합화합물 제조를 위하여 $Mg(OH)_2$, $Sb_{2}O_{3}$, 붕산아연 등의 난연성 화합물을 사용하였으며 각 화합물의 최적배합 비율은 1: 2: 2였다. 최종적으로 난연 복합화합물을 바인더(마이셀 2%) 및 용제(물)와 1: 0.5: 0.5로 배합하여 난연도료를 제조하여 그 난연 성능을 테스트하였다.

• 한국자기학회지
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• 제23권6호
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• pp.184-187
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• 2013

MgO 기반 스핀소자에 유기장벽 Cu-Phthalocyanine(CuPc)가 삽입된 무기${\backslash}$유기 터널 접합 소자 Fe${\backslash}$MgO(001)${\backslash}$CuPc${\backslash}$Co의 자기 저항 현상과 그 계면 특성의 상관관계에 대한 연구가 진행되었다. 특히 1.6 nm MgO(001)${\backslash}$x nm CuPc(x = 0~5) 계면의 전자기적 특성을 스핀 편극된 준안정상태 He 원자 분광계(Metastable Helium De-excitation Spectroscopy, MDS)를 이용하여 규명하였다. 에피 성장된 MgO(001) 위에 적층된 약 1.6 nm 두께의 CuPc 층상구조의 표면에서, MgO(001) 하지층의 표면과는 달리, up-spin band와 down-spin band의 비대칭성이 현저해지는 것으로 관찰되었다. 이 결과는 실온과 저온(77 K)에서 ~10 %와 30 %로 각각 측정된 자기저항 현상과 복합장벽을 통과하는 스핀거동을 이해하는데 중요한 단초를 제공해 준다.

• 한국결정성장학회지
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• 제23권5호
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• pp.230-234
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• 2013

ATO 나노 입자들로 구성된 적외선 차단 박막이 솔-젤 법에 의해 성공적으로 제조되었다. 코팅액은 유무기 하이브리드 바인더와 콜로이드 ATO 용액으로 합성되었고 ATO 박막은 슬라이드 유리기판에 5~40 mm/s의 인상속도로 코팅되었다. 인상속도가 5 mm/s에서 40 mm/s로 증가함에 따라 코팅막의 두께 또한 $1.05{\mu}m$에서 $4.25{\mu}m$로 증가하였다. 그리고 파장 780 nm에서 2500 nm에서의 적외선 차단율은 49.5 %에서 66.7 %로 증가하였다. 또한 $80^{\circ}C$에서 건조된 ATO 박막의 연필경도 값은 5H를 나타내었고 tetraethylorthosilicate와 methyltrimethoxysilane을 합성한 하이브리드 바인더의 영향으로 테이프테스트 후 코팅막은 벗겨지지 않았다. 서로 다른 인상속도에 의해 제조된 박막의 표면구조, 광학적 특성 그리고 박막두께는 FE-SEM, UV-Vis-NIR 분광기 그리고 Dektak에 의해 측정되었다.

• 대한소아치과학회지
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• 제29권3호
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• pp.362-370
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• 2002

최근 20년간 다양한 종류의 심미 수복재가 개발되었고, 특히 지난 5년 동안에는 그 수에 있어서 극적인 증가추세를 보였다. 최근 들어, ormocer라는 새로운 종류의 광중합형 수복재료가 소개되었는데, 화학 분야에서는 이미 오래 전부터 알려져 있던 성분으로, 광학렌즈 등의 표면경화제로 이용되어 오다가 최근 치과용 수복재에 도입되었다. 'Ormocer' 란 'Organically Modified Ceramics'의 약자로 'Ormosils' (Organically Modified Silicates)로도 알려져 있다. 그러나, 이 새로운 수복재에 대한 연구는 아직 미흡한 실정이다. 본 연구에서는 서로 다른 계통의 광중합형 수복재들(Z-100, Surefil, Tetric Ceram, Dyract AP)과 ormocer(Admira)를 압축강도와 굴곡강도 측면에서 비교 평가하고, 구강내 환경과 유사한 조건에서 수분흡수가 그 물성에 미치는 영향을 평가할 목적으로 시도되어 다음과 같은 결과를 얻었다. 1. 1일 후에 측정한 Admira의 압축강도는 Surefil보다는 낮았으나, 다른 재료들과는 유의한 차이를 나타내지 않았다(p>0.05). 2. 1일 후에 측정한 Admira의 굴곡강도는 다른 4종의 재료에 비해서 낮았다(p<0.05). 2일부터는 3종의 복합레진에 비해서 낮았다(p<0.05). 3. 실험기간(30일) 중 hybrid composite resin군(Z-100, Tetric Ceram)과 packable resin(Surefil)군 간에는 압축강도와 굴곡강도에서 유의한 차이가 없었다(p>0.05). 4. 실험에 사용된 5종의 수복재 모두 압축강도와 굴곡강도가 2일까지 증가하다가 7일부터 감소하였다(p<0.05). 5. 각 재료의 시간에 따른 압축강도와 굴곡강도의 변화양상은 통계적으로 유사하였다(p>0.05).

• 한국콘텐츠학회논문지
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• 제21권12호
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• pp.918-925
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• 2021

페로브스카이트 태양전지는 기존의 실리콘 태양전지를 대체하는 차세대 태양전지로서, 페로브스카이트 구조를 가진 유-무기 하이브리드 물질을 광 활성층으로 사용하는 태양전지 소자로 고효율, 저가의 용액 공정 및 저온 공정에 유리한 장점들을 가지고 있으며 지난 10년간 빠른 효율 향상을 보여주었다. 이러한 페로브스카이트 태양전지의 상용화 과정에서 대면적 코팅 방법에 대해서 연구개발이 진행되어야 한다. 대면적 페로브스카이트 태양전지 대면적 코팅 방법 중 하나로 슬롯-다이 코팅방법에 대해서 연구 진행하였다. 메니스커스를 이용하여 기판 위를 지나가며 용액을 코팅하는 방법으로 3D printer에 메니스커스를 장착하여 코팅을 할 수 있도록 하였다. 코팅 시 작용하는 변수로는 bed 온도, coating speed, N₂ blowing간격, N₂ blowing 높이, N₂ blowing세기등이 있으며 이를 조절하여 페로브스카이트 흡수층을 제작 진행하였으며, 대면적 소자 제작을 위한 코팅 조건을 최적화 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.17-18
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• 2011

Plasma in liquid phase has attracted great attention in the last few years by the wide domain of applications in material processing, decomposition of organic and inorganic chemical compounds and sterilization of water. The plasma in liquid is characterized by three main regions which interact each - other during the plasma operation: the liquid phase, which supply the plasma gas phase with various chemical compounds and ions, the plasma in the gas phase at atmospheric pressure and the interface between these two regions. The most complex region, but extremely interesting from the fundamental, chemical and physical processes which occur here, is the boundary between the liquid phase and the plasma gas phase. In our laboratory, plasma in liquid which behaves as a glow discharge type, is generated by using a bipolar pulsed power supply, with variable pulse width, in the range of 0.5~10 ${\mu}s$ and 10 to 30 kHz repetition rate. Plasma in water and other different solutions was characterized by electrical and optical measurements. Strong emissions of OH and H radicals dominate the optical spectra. Generally water with 500 ${\mu}S/cm$ conductivity has a breakdown voltage around 2 kV, depending on the pulse width and the repetition rate of the power supply. The characteristics of the plasma initiated in ultrapure water between pairs of different materials used for electrodes (W and Ta) were investigated by the time-resolved optical emission and the broad-band absorption spectroscopy. The deexcitation processes of the reactive species formed in the water plasma depend on the electrode material, but have been independent on the polarity of the applied voltage pulses. Recently, Coherent anti-Stokes Raman Spectroscopy method was employed to investigate the chemistry in the liquid phase and at the interface between the gas and the liquid phases of the solution plasma system. The use of the solution plasma allows rapid fabrication of the metal nanoparticles without being necessary the addition of different reducing agents, because plasma in the liquid phase provides a reaction field with a highly excited energy radicals. We successfully synthesized gold nanoparticles using a glow discharge in aqueous solution. Nanoparticles with an average size of less than 10 nm were obtained using chlorauric acid solutions as the metal source. Carbon/Pt hybrid nanostructures have been obtained by treating carbon balls, synthesized in a CVD chamber, with hexachloro- platinum acid in a solution plasma system. The solution plasma was successfully used to remove the template remained after the mesoporous silica synthesis. Surface functionalization of the carbon structures and the silica surface with different chemical groups and nanoparticles, was also performed by processing these materials in the liquid plasma.