졸-겔법을 이용한 투과성 TiO₂ 분말 및 박막의 특성 연구

정미원,이지영,손현진,Jung, Mie-Won,Lee, Zee-Young,Son, Hyun-Jin 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.3

Titanium(IV) isopropoxide에 킬레이팅 리간드로 Acetylacetone(Acac), Ethyl-acetoacetate(Etac) 그리고, Ethanolamine을 첨가시켜 변형된 티타늄 알콕사이드를 합성한 후 졸-겔 방법으로 투과성 티타늄 산화물 박막을 제조하였다. 박막 제조 조건이 최적의 상태일 때는 티타니아 졸 용액의 농도가 3wt% 이하이고, 리간드로는 Acetyl acetone(Acac)를 선택하고, pH가 2.5로 조절하였을 때였다. 순수한 티타늄 산화물 박막보다는 리간드가 치환된 박막들의 굴절률이 더 높았고 가시광선 영역에서 80% 이상의 투과율을 나타냄을 알 수 있었다. 티타니아 졸 상태에서는 입자 크기가 나노 크기를 나타냈으며 분말로 소성 후 마이크론 크기로 증가함을 알 수 있었다. 티타늄 박막들은 400$^{\circ}$C에서 무정형에서 anatase로 상전이가 일어나고 700$^{\circ}C$에서는 rutile로 변화됨을 XRD로 관찰하였다. 박막의 결정형태와 모양 및 크기도 SEM과 XRD로 측정하였다. 또한 분말의 물성 및 구조를 SEM, XRD, TGA 그리고 DSC로 알아보았고, 박막의 광학적 특성에 대해서는 ellipsometer로 굴절률과 막두께를 측정하여 비교하여 보았다. Transparent $TiO_2$ thin films prepared by sol-gel process using the modification of titanium(IV) alkoxide showed improved thermal stability and high refraction index. Compared to the pure $TiO_2$ film, the modified $TiO_2$ films show the increased index of refraction under proper condition at pH 2.5. Transparency of these $TiO_2$ thin films were more than 80% in the visible region. It has been demonstrated that the reaction occurs in the amorphous phase: an exchange of phase results in anatase before and after 400$^{\circ}C$, in rutile over 700$^{\circ}$C form the XRD results. The particle sizes, shapes and structures of these nanoclusters in the $TiO_2$ films have been identified through a SEM and XRD. The physical properties and structures of their powders have also been studied through a SEM, XRD, TGA and DSC. The thickness and index of refraction have been determined by the analysis of ellipsometric spectra.

Titanium(IV) isoproxide 유도체의 합성 및 특성연구

정미원,Jung, Mie-Won 한국분석과학회 1999 분석과학 Vol.12 No.6

Titanium(IV) isoproxide에 유기첨가제로 아세트산을 첨가하여 단일성분계인 치환된 titanium(IV) isoproxide를 합성한다. 합성된 titanium 착화합물은 세가지 형태로 된 5배위 및 6배위의 구조로 존재함을 FT-IR, $^1H$ 및 $^{13}C$ NMR 그리고 UV-Vis 스펙트라로 확인하였다. 이 착물에 대한 가수분해 반응을 $^1H$-NMR spectroscopy를 이용해 관찰하였고 FT-IR spectroscopy로 가수분해 및 건조시킨 후의 구조 변화를 관찰하여 보았으며 리간드의 존재 유무도 살펴보았다. The systematic modification of titanium(IV) isopropoxide with acetic acid as a organic additive was done and identifided by FT-IR, $^1H$, $^{13}C$ NMR and UV-Vis spectroscopy. The structure was cbanged after hydrolysis-condensation reaction and drying process. The hydrolysis-condensation rates of modified Ti alkoxide with acetic acid were investigated by $^1H$ NMR spectroscopy. This modified Ti(IV) alkoxide was less reactive toward hydrolysis-condensation reaction than $Ti(OPr^i)_4$, which can be attributed to the stable ligand structure between Ti alkoxide and ligand. The structural change on obtained from gel powders with heat treatment was also observed by FT-IR spectroscopy.

La이 도핑된 CuO-ZnO-Al₂O₃ 복합 산화물의 합성공정개발

정미원,임샛별,문보람,홍태환,Jung, Mie-Won,Lim, Saet-Byeol,Moon, Bo-Ram,Hong, Tae-Whan 한국재료학회 2011 한국재료학회지 Vol.21 No.1

La doped CuO-ZnO-$Al_2O_3$ powders are prepared by sol-gel method with aluminum isopropoxide and primary distilled water as precursor and solvent. In this synthesized process, the obtained metal oxides caused the precursor such as copper (II) nitrate hydrate and zinc (II) nitrate hexahydrate were added. To improve the surface areas of La doped CuO-ZnO-$Al_2O_3$ powder, sorbitan (z)-mono-9-octadecenoate (Span 80) was added. The synthesized powder was calcined at various temperatures. The dopant was found to affect the surface area and particle size of the mixed oxide, in conjunction with the calcined temperature. The structural analysis and textual properties of the synthesized powder were measured with an X-ray Diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), Bruner-Emmett-Teller surface analysis (BET), Thermogravimetry-Differential Thermal analysis (TG/DTA), $^{27}Al$ solid state Nuclear Magnetic Resonance (NMR) and transform infrared microspectroscopy (FT-IR). An increase of surface area with Span 80 was observed on La doped CuO-ZnO-$Al_2O_3$ powders from $25m^2$/g to $41m^2$/g.

금 나노미립자가 함침된 $TiO_2/SiO_2$ 박막의 광학적 성질

정미원,김지은,이경철,Jung, Mie-Won,Kim, Ji-Eun,Lee, Kyung-Chul 대한화학회 2000 대한화학회지 Vol.44 No.1

표면공명흡수는 매질의 유전상수값에 의존한다. 금 나노미립자가 함침된 $TiO_2/SiO_2$ 복합산화물 박막을 $Ti(OPr^i)_4$과 $Si(OEt)_4$, 그리고 $HAuCl_4{\cdot}7H_2O$를 사용하여 졸-겔 방법으로 제조하였다. $TiO_2/SiO_2$ 박막에 함침된 금 나노미립자의 최대 표면 공명 흡수는 $TiO_2/SiO_2$의 몰비에 따라 540 nm에서 615 nm 까지 선형적으로 변하였다. 이러한 박막에 함침된 금 나노미립자의 크기와 구조를 TEM과 XRD로 측정하였다. 그리고 $TiO_2/SiO_2$ 박막의 유전상수값을 실험 data로부터 이론적으로 계산하였다 The wavelength of the surface plasmon absorption depends on the dielectric matrix. $TiO_2/SiO_2$ complex oxide films doped with Au nanoclusters were prepared by sol-gel spin-coating method using $Ti(OPr^i)_4$, $Si(OEt)_4$, and $HAuCl_4{\cdot}7H_2O$. The wavelength of the maximum absorption of Au nanoehrsters in the $TiO_2/SiO_2$ thin films was obtained with lineality from 540 nm to 615 nm depending on the molar ratio of $TiO_2$. The particle sizes and structures of these nanoclusters have been identified through a TEM and X-ray diffraction patterns. The dielectric constants of $TiO_2/SiO_2$ thin films were calculated from the experimental results.

고분자 P123와 란탄이 도핑된 알루미나의 특성 연구

정미원,이미회,Jung, Mie-Won,Lee, Mi-Hoe 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.5

To direct the evolution of nanostructure and immobilize ${\gamma}-Al_2O_3$ catalyst, nanocrystalline La-doped-$Al_2O_3$ powder were prepared by the sol-gel process with addition of an amphiphilic block copolymer template (pluronic P123: $(poly(ethyleneoxide)_{20}-poly(propyleneoxide)_{70}-poly(ethyleneoxide)_{20})$. The dried gel is amorphous, whereas heating at temperature above $700^{\circ}C$ leads to the formation of nanocrystalline ${\gamma}$ and ${\delta}-Al_2O_3$ and these two phases is kept until $1100^{\circ}C$. ${\alpha}-A1_2O_3 $starts to form at $1200^{\circ}C$ with $LaAl_{11}O_{18}$. The surface morphology and crystal structure has been observed by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). Solid state $^{27}Al$ MAS NMR indicates two types of local environment, i.e. octahedral and tetrahedral sites. The surface area and pore size was compared among these powders using the BET nitrogen adsorption measurements.

SnO₂가 도핑된 TiO₂ 박막의 합성 및 광촉매 효과

정미원,곽윤정,Jung, Mie-Won,Kwak, Yun-Jung 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.11

[ $SnO_2$ ]-doped $TiO_2$ thin films were prepared from tin (IV) bis (acetylacetonate) dichloride and titanium diisopropoxide bis (acetylacetonate) with pluronic P123 or degussa P25 as a structural-directing agent. These hydrolyzed sol were spin coated onto Si(100) wafer substrate. The microstructure, morphology and bonding states of thin films were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of these films was investigated by using indigo carmine solution.

졸-겔공정에 의해 실리카 구조체에 도입된 유기 NLO 물질의 특성

정미원,문정호,설용건,( Mie Won Jung,Jeong Ho Mun,Yong Gun Shul,Tatsuo Wada ) 한국공업화학회 1993 공업화학 Vol.4 No.3

반응성과 성형성이 우수한 졸-겔법을 이용하여 비선형 광학물질인 MNA(2-Methyl-7-nitro-aniline), Carbazole 1(5-Nitro-9-hydroxyethyl Carbazole), Carbazole 2(5-Nitro-9-ethyl Carbazole) 그리고 DR1 (Disperse Red 1)을 Silica matrix에 조합시킨 유-무기계 복합박막을 제조하였다. 이들 유-무기계 복합박막의 열적 안정도와 분해정도를 비교한 결과 -OH기를 갖는 Carbazole 1과 DR 1이 열분해에 대한 안정성이 우수하다는 것을 알았다. Carbazole 1의 편극화 처리로 UV 흡광도의 현저한 감소가 일어났고 상온에서 전기장을 제거하자 UV 흡광도의 느린 회복이 발견되었다. Organic nonlinear optical materials such as MNA(2-Methyl-4-nitro-aniline), Carbazole 1 (5-Nitro-9-hydroxyethyl Carbazole), Carbazole 2 (5-Nitro-9-ethyl Carbazole) and DR 1(Disperse Red 1) were incorporated into silica matrix to form a composite thin films. The thermal stability and degree of degradation were compared to these organic-inorganic composite film. Among those films, Carbazole 1 and DR 1 which have terminal -OH group showed enhanced stability for thermal degradation. The effect of polarization and degree of relaxation for the composite thin films incorporated with Carbazole 1 were measured by the absorbance change of UV spectra with time. With polarization treatment of Carbazole 1 incorporated composite film, the intensity of UV absorbance was remarkably reduced. And slow relaxation of Carbazole 1 molecule was suggested from the slightly recovered intensity of UV absorbance after removing the electric field at room temperature.

Quinacridone을 첨가시킨 SnO2가 도핑된 TiO2 분말의 광촉매 특성

정미원 ( Mie Won Jung ),곽윤정 ( Yun Jung Kwak ) 한국공업화학회 2007 공업화학 Vol.18 No.6

고분자 첨가법에 의해 SnO2가 도핑된 TiO2 분말의 합성 및 광촉매 특성(단 신)

정미원 ( Mie Won Jung ),곽윤정 ( Yun Jung Kwak ) 한국공업화학회 2006 공업화학 Vol.17 No.5

전이금속 - 크라운 에테르 화합물의 구조와 특성 연구

정미원(Mie Won Jung),박정옥(Jung Ok Park) 성신여자대학교 기초과학연구소 2001 基礎科學硏究誌 Vol.19 No.-