유기전기발광 소자에서 천연색을 구현하기 위해서는 적색, 녹색, 청색 발광물질이 필요하다. 그러나 적색과 녹색의 발광 물질에 대한 연구는 매우 활발하나 청색의 물질에 대한 연구가 미흡한 것은 높은 발광 에너지 때문으로 보인다. 본 연구는 발광 효율이 높으며 열적 안정성이 좋은 화합물을 합성하려는 것으로 carbazole로 치환된 anthracene 화합물 합성에 관한 것이다. Tert-butyl 기로 치환된 carbazole에 전기 발광 성질과 열적 안정도가 좋은 anthracene을 직접 결합시킴으로써 정공전달 특성을 갖는 작용기와 전자전달 특성을 갖는 작용기 간의 거리에 대한 연구를 시작하고자 하였다.

Ammonium dinitramide (AND) is one of the most promising oxidizers in propellants without chlorinated pollution to the atmosphere in these days. Potassium sulfamate (PS) is a key substance in ADN synthesis as forming nitrates such as -N(NO2)2. In this paper, potassium sulfamate as a starting material for ADN synthesis was prepared in a lab scale through crystallization with ethanol solvent, and observed the effects on the yield and purity of KDN. The prepared potassium sulfamates were analyzed using FE-SEM, XRD, BET and TGA-DSC. The lab-made PS, which was ground to 20μm showed more beneficial than a commercial product achieving high yield and purity of the synthesized KDN. It would be associated closely with crystallinity, porosity and pore size of prepared PS.

알킬렌디아미노 기능기를 분자 내에 갖는 4종의 새로운 알킬렌디아미노알킬-비스-포스폰산 유도체들을 합성하고, 그들의 연기밀도를 측정하였다. 이 화합물들은 알킬렌디아민 및 알데히드에 인산을 첨가하여 한 단계로 반응시켜 2개의 인산에 2개의 아미노기를 갖는 화합물로서 76~97.3%의 수율을 얻었다. 이들의 연기밀도 시험은 ASTM E 662의 방법으로 측정하였으며, 시험결과 연기밀도(Ds)값이 234.7~437.9으로 측정되었고, 2개의 인산을 갖는 화합물이 1개의 인산구조를 갖는 화합물보다 연기밀도가 증가되었다. 따라서 하나 또는 두 개의 인산에 결합된 아마노기의 질소수와 연기밀도 사이에는 관련이 있었다.

Well-distributed SnO2-Sn-Ag3Sn nanoparticles embedded in carbon nanofibers were fabricated using a co-electrospinning method, which is set up with two coaxial capillaries. Their formation mechanisms were successfully demonstrated. The structural, morphological, and chemical compositional properties were investigated by field-emission scanning electron spectroscopy (FESEM), bright-field transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In particular, to obtain well-distributed SnO2 and Sn and Ag3Sn nanoparticles in carbon nanofibers, the relative molar ratios of the Ag precursor to the Sn precursor including 7 wt% polyacrylonitrile (PAN) were controlled at 0.1, 0.2, and 0.3. The FESEM, bright-field TEM, XRD, and XPS results show that the nanoparticles consisting of SnO2-Sn-Ag3Sn phases were in the range of ~4 nm-6 nm for sample A, ~5 nm-15 nm for sample B, ~9 nm-22 nm for sample C. In particular, for sample A, the nanoparticles were uniformly grown in the carbon nanofibers. Furthermore, when the amount of the Ag precursor and the Sn precursor was increased, the inorganic nanofibers consisting of the SnO2-Sn-Ag3Sn nanoparticles were formed due to the decreased amount of the carbon nanofibers. Thus, well-distributed nanoparticles embedded in the carbon nanofibers were successfully synthesized at the optimum molar ratio (0.1) of the Ag precursor to the Sn precursor after calcination of 800˚C.

In this study, GaN powders were synthesized from gallium oxide-hydroxide (GaOOH) through an ammonification process in an NH3 flow with the variation of B2O3 additives within a temperature range of 300-1050˚C. The additive effect of B2O3 on the hexagonal phase GaN powder synthesis route was examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transformation infrared transmission (FTIR) spectroscopy. With increasing the mol% of B2O3 additive in the GaOOH precursor powder, the transition temperature and the activation energy for GaN powder formation increased while the GaN synthesis limit-time (tc) shortened. The XPS results showed that Boron compounds of B2O3 and BN coexisted in the synthesized GaN powders. From the FTIR spectra, we were able to confirm that the GaN powder consisted of an amorphous or cubic phase B2O3 due to bond formation between B and O and the amorphous phase BN due to B-N bonds. The GaN powder synthesized from GaOOH and B2O3 mixed powder by an ammonification route through β-Ga2O3 intermediate state. During the ammonification process, boron compounds of B2O3 and BN coated β-Ga2O3 and GaN particles limited further nitridation processes.

Fe-TiC composite powder was fabricated via two steps. The first step was a high-energy milling of FeO and carbon powders followed by heat treatment for reduction to obtain a (Fe+C) powder mixture. The optimal condition for high-energy milling was 500 rpm for 1h, which had been determined by a series of preliminary experiment. Reduction heat-treatment was carried out at for 1h in flowing argon gas atmosphere. Reduced powder mixture was investigated by X-ray Diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM) and Laser Particle Size Analyser (LPSA). The second step was a high-energy milling of (Fe+C) powder mixture and additional powder, and subsequent in-situ synthesis of TiC particulate in Fe matrix through a reaction of carbon and Ti. High-energy milling was carried out at 500 rpm for 1 h. Heat treatment for reaction synthesis was carried out at for 1 h in flowing argon gas atmosphere. X-ray diffraction (XRD) results of the fabricated Fe-TiC composite powder showed that only TiC and Fe phases exist. Results from FE-SEM observation and Energy-Dispersive X-ray Spectros-copy (EDS) revealed that TiC phase exists uniformly dispersed in the Fe matrix in a form of particulate with a size of submicron.

phosphor powders were synthesized using a seed (average particle size: 5 ) by the polymer solution route. PVA solution was added to the sol precursors consisting of the seed powder and metal nitrate salts for homogeneous mixing in atomic scale. All dried precursor gels were calcined at and then heated at in atmosphere. The final powders were characterized by using XRD, SEM, PSA, PL and PKG test. All synthesized powders were crystallized to YAG phase without intermediate phases of YAM or YAP. The phosphor properties and morphologies of the synthesized powders were strongly dependent on the PVA content. Finally, the synthesized phosphor powder heated at , which is prepared from 12:1 PVA content and has an average particle size of 15 , showed similar phosphor properties to a commercial phosphor powder.

본 연구에서는 수용성 아크릴을 합성한 다음 수성 카제인 수지를 합성하여 기합성 완성된 아크릴 수지에 카제인 수지의 적하량을 점차 증가시켜 변화하는 물성을 피혁(Lamb leather)에 표면 코팅하여 물성을 측정 분석하였다. 내용제성 측정 결과 높은 내용제성 물성을 지닌 아크릴 수지와 카제인 수지의 함량이 물성 변화에 끼치지 않았으며 모두 높은 물성치를 나타내었다. 인장 강도 측정치에서는 아크릴 단독 코팅의 측정치가 1.399kgf/mm2로 가장 낮은 수치를 나타내었으며, 카제인 수지의 합량이 제일 높은 WAC-3가 가장 높은 인장력 1.426kgf/mm2을 나타내었다. 또한 내마모도 측정에서는 WAC-3가 제일 높은 69.774 mg.loss로 우수한 물성변화를 나타내었고, 연실률의 경우 아크릴 단독 코팅인 WAR이 820 %로 가장 높은 수치를 나타내었다.

본 연구에서는 용매열합성법(solvothermal method)을 이용해 나노기공 HKUST-1 분리막을 제조하였다. In-situ 용매열합성법을 이용하는 경우, 매크로 기공의 알루미나 지지체 위에 균일하고 균열이 없는 HKUST-1 층을 형성하기 어렵다. 본 연구에서는 용매열합성 전에 알루미나 지지체의 표면을 가열한 상태에서 용매열합성의 전구체 용액을 분무하므로 연속적이고 균열이 없는 HKUST-1 분리막을 제조할 수 있었다. 합성된 HKUST-1 분리막은 XRD, FE-SEM 및 단일 기체투과 실험 등을 통해 분석하였다.

유러피언(Eu) 착물을 이용하여 산화 그래핀 시트와 비공유 결합방법을 이용하여 제조하였으며, 산화 그래핀(GOS)뿐만 아니라 혼합된 각각의 물질의 특성을 유러피언(Eu) 착물의 흡착을 확인하였다. 또한, 하이브리드 산화 그래핀(GOS)-유러피언(Eu) 착물의 최종생성물은 생물학적 labeling과 anti-counterfeiting 등 여러 실용적인 분야에 적용 가능한 밝은 적색의 발광을 방출하는 물질이다.

Nano Pd spot-coated active carbon powders were synthesized by a hydrothermal-attachment method (HAA) using PVP capped Pd colloid in a high pressure bomb at , 450 psi, respectively. The PVP capped Pd colloid was synthesized by the precipitation-redispersion method. PVP capped Pd nano particles showed the narrow size distribution and their particle sizes were less than 8nm in diameter. In the case of nano Pd-spot coated active carbon powders, nano-sized Pd particles were adhered in the active carbon powder surface by HAA method. The component of Pd was homogeneously distributed on the active carbon surface.

Nickel oxide was doped with a wide range of concentrations (mol%) of Aluminum (Al) by solvothermal synthesis;single-phased nano powder of nickel oxide was generated after calcination at 900oC. When the concentration of Al dopant wasincreased, the reduced intensity was confirmed through XRD analysis. Lattice parameters of the synthesized NiO powder weredecreased after treatment of the dopant; parameters were increased when the concentration of Al was over the doping limit(5mol% Al). The binding energy of Ni2+ was chemically shifted to Ni3+ by doping Al3+ ion, as confirmed by the XPS analysis.The tilted structure of the synthesized NiO with 5mol% Al dopant and the polycrystalline structure of the Ni0.75Al0.25O wereobserved by HR-TEM analysis. The electrical conductivity of the newly synthesized NiO was highly improved by Al dopingin the conductivity test. The electrical conductivity values of the commercial NiO and the synthesized NiO with 5mol% Aldopant (Ni0.95Al0.05O) were 1,400s/cm and 2,230s/cm at 750oC, respectively. However, the electrical conductivity of thesynthesized NiO with 10mol% Al dopant (Ni0.9Al0.1O) decreased due to the scattering of free-electrons caused by the largenumber of impurity atoms; the electrical conductivity of Ni0.9Al0.1O was 545s/cm at 750oC.

We report on the NO gas sensing properties of non-directional ZnO nanofibers synthesized using a typical electrospinning technique. These non-directional ZnO nanofibers were electrospun on an SiO2/Si substrate from a solution containing poly vinyl alcohol (PVA) and zinc nitrate hexahydrate dissolved in distilled water. Calcination processing of the ZnO/PVA composite nanofibers resulted in a random network of polycrystalline ZnO nanofibers of 50 nm to 100 nm in diameter. The diameter of the nanofibers was found to depend primarily on the solution viscosity; a proper viscosity was maintained by adding PVA to fabricate uniform ZnO nanofibers. Microstructural measurements using scanning electron microscopy revealed that our synthesized ZnO nanofibers after calcination had coarser surface morphology than those before calcination, indicating that the calcination processing was sufficient to remove organic contents. From the gas sensing response measurements for various NO gas concentrations in dry air at several working temperatures, it was found that gas sensors based on electrospun ZnO nanofibers showed quite good responses, exhibiting a maximum sensitivity to NO gas in dry air at an operating temperature of 200˚C. In particular, the non-directional electrospun ZnO nanofiber gas sensors were found to have a good NO gas detection limit of sub-ppm levels in dry air. These results illustrate that non-directional electrospun ZnO nanofibers are promising for use in low-cost, high-performance practical NO gas sensors.

버섯 재배기술이 발전하여 느타리와 큰느타리의 전체 생산 및 소비가 버섯전체생산의 약 50%를 차지하여 재배품종의 주류를 형성하고 있다. 하지만 UPOV 및 FTA 등의 문호개방에 따라 로열티 지불 등에 대응할 수 있는 품종육성이나 자체 고유품종 육성을 위한 신기술개발이 시급한 실정이다. 본 연구에서는 품종육성의 기초기반 연구로 느타리버섯의 12,342 ESTs 분석을 통하여 세포막의 구성물질인 ergosterol 생합성관련 유전자 동정을 한 결과 12개의 유전자 중에서 9개가 동정되어 이에 대한 발현 분석 중이며, 느타리버섯의 부가가치에 가장 중요한 멜라닌 색소 유전자가 아직까지 동정되지 않아 집중적으로 분석한 결과 Tyrosine 생합성대사관련 유전자인 DOPA 4,5-dioxygenase가, 그리고 Acetate 생합성대사 관련유전자 THR1 (1,3,8-Trihydroxynaphthalene reductase)이 동정되어 느타리버섯의 멜라닌 생합성에는 하나의 대사기작이 아닌 복합기작에 의해 색소를 생성함을 유추할 수 있었다.

Metal nanowires can be coated on various substrates to create transparent conducting films that can potentially replace the dominant transparent conductor, indium tin oxide, in displays, solar cells, organic light-emitting diodes, and electrochromic windows. One issue with these metal nanowire based transparent conductive films is that the resistance between the nanowires is still high because of their low aspect ratio. Here, we demonstrate high-performance transparent conductive films with silver nanofiber networks synthesized by a low-cost and scalable electrospinning process followed by two-step sequential thermal treatments. First, the PVP/AgNO3 precursor nanofibers, which have an average diameter of 208 nm and are several thousands of micrometers in length, were synthesized by the electrospinning process. The thermal behavior and the phase and morphology evolution in the thermal treatment processes were systematically investigated to determine the thermal treatment atmosphere and temperature. PVP/AgNO3 nanofibers were transformed stepwise into PVP/Ag and Ag nanofibers by two-step sequential thermal treatments (i.e., 150˚C in H2 for 0.5 h and 300˚C in Ar for 3 h); however, the fibrous shape was perfectly maintained. The silver nanofibers have ultrahigh aspect ratios of up to 10000 and a small average diameter of 142 nm; they also have fused crossing points with ultra-low junction resistances, which result in high transmittance at low sheet resistance.

이 연구에서는 친환경 선박용 재료로 각광받는 탄소나노물질에 대하여 실험적 연구를 수행하였다. 탄소나노물질의 합성을 위한 열원으로서는 대향류 메탄 화염을 이용하였다. 탄소나노물질 합성을 위한 촉매로서는 페로센을 사용하였다. 합성 특성을 파악하기 위한 주요 파라메타로는 대향류 메탄 화염에 수소의 혼합 비율과 샘플링 위치를 변화시켰다. 탄소나노물질의 성향은 SEM과 TEM 이미지를 이용하여 결정되었다. 실험 결과로서는 수소의 혼합 비율이 증가할수록 탄소나노물질의 생성이 잘 이루어졌다. 또한 대향류 메탄 확산화염 내 탄소나노튜브의 생성을 위한 적정 온도로는 1500 K 정도가 적당하다는 것을 알 수 있었다.

Single crystalline Cu nanowires with controlled diameters and aspect ratios have been synthesized using electrochemical deposition within confined nanochannels of a porous anodic aluminium oxide(AAO) template. The diameters of nano-sized cylindrical pores in AAO template were adjusted by controlling the anodization conditions. Cu nanowires with diameters of approximately 38, 99, 274 nm were synthesized by the electrodeposition using the AAO templates. The crystal structure, morphology and microstructure of the Cu nanowires were systematically investigated using XRD, FE-SEM, TEM and SAED. Investigation results revealed that the Cu nanowires had the controlled diameter, high aspect ratio and single crystalline nature.