• Title/Summary/Keyword: $Tio_2$

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Preparation of Asymmetric Ceramic Membrane by Coating-Pyrolysis Process (도포-열분해법을 이용한 비대칭 세라믹 분리막 제조)

  • Ryu, Hyun-Wook;Kim, Byung-Hoon
    • Journal of the Korean Ceramic Society
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    • v.39 no.12
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    • pp.1153-1157
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    • 2002
  • The fabrication of a three-layered asymmetric ceramic membrane was performed by slip casting of the porous alumina support and dip coating of the alumina intermediate layer using high purity ${\alpha}-Al_2O_3$ powders that have different particle size, followed by screen printing-pyrolysis of the $Tio_2$ layer as an ultrafilteration membrane using Ti-naphthenate solution. The bending strength, porosity and mean pore size of the alumina support were 231 kg/$cm^2$s, 30.26% and 0.19 ${mu}m$, respectively. The thickness of the intermediate layer was 30 ${mu}m$ and the mean pore size of that was 0.063 ${mu}m$. Also, the top layer was 0.5 ${mu}m$ thick and micropores with about 20 nm size were formed uniformly.

Characteristics of Ring-Opening Isomerization Polymerization of [4.3.0] Cyclic Pseudoureas ([4.3.0] 환상 유사 우레아의 이성화 개환중합과 특성평가)

  • Lee, Chan-Woo;Chung, Jin-Do
    • Polymer(Korea)
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    • v.35 no.4
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    • pp.308-313
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    • 2011
  • The ring-opening isomerization polymerization behavior of 2,5,6,7-tetrahydro-3H-imidazo[2,1-b] [1,3] oxazine(TII) has been studied under various conditions. The present study aimed at improving the low polymerizability of the above monomer (six-membered ring) up to a level comparable to that of 2,5,6-tetrahydroimidazo[2,1-b] [l,3] oxazole(TIO) (five-membered ring). The optimum result could be observed when methyl trifluoromethanesulfonate(MeOTf) and nitrobenzene were used as an initiator and a solvent in the polymerization at $60^{\circ}C$ for 24 h. Polymers were confirmed by$^1H$ NMR과$^{13}C$ NMR, and m measurements. The molecular weight obtained by gel permeation chromatography (GPC) corresponded to the molecular weight theoretically calculated from the feed ratio. The melting temperature ($T_m$) of TII was conspicuously different from that of TIO, because of the difference in the alkyl group.

선형대향타겟 스퍼터를 이용하여 성막시킨 InSnTiO 박막의 특성 연구

  • Sin, Hae-In;Kim, Han-Gi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.245-245
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    • 2016
  • 본 연구에서는 선형 대향 타겟 스퍼터 (Linear Facing Target Sputtering: LFTS) 시스템을 이용하여 ITO와 Ti doped $In_2O_3$ (TIO) 타겟을 Co-sputtering한 InSnTiO 투명 전극의 전기적, 광학적 특성을 연구하였다. InSnTiO 투명전극의 전기/광학적 및 구조적 특성은 Hall measurement, UV/Vis spectrometry, X-ray Diffraciton 분석법을 통해 최적화 하였고, DC power, substrate to target distance (TSD), target to target distance (TTD), ambient treatment 변수 조절을 통해 최적화된 LFTS InSnTiO 투명전극을 제작하였다. LFTS 공정을 이용한 InSnTiO 투명전극의 성막 공정 중 DC파워와 공정압력 변화에 따른 구조적, 표면적 특성 변화는 Field-Emission Scanning Electron Microscopy (FE-SEM) 과 X-ray Diffractometer (XRD) 분석을 통해 관찰하였다. 이렇게 증착된 InSnTiO 투명전극은 급속열처리 시스템으로 (Rapid Thermal Annealing system) 후열처리를 진행하여 투과도의 향상과 면저항의 감소를 확인하였다. 본 연구에서는 다양한 분석을 통해 Co-sputtering한 InSnTiO 박막의 특성과 다양한 장점을 소개한다.

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The Weathering Resistance of Sol-Gel Derived Anti-Reflective SiO2-Tio2 Thin Films (졸-겔법에 의한 SiO2-Tio2계 박막의 내후성)

  • Kim, Sangmoon;Lim, Yongmu;Hwang, Kyuseog
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.237-242
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    • 1998
  • A transparent and colorless $80SiO_2-20TiO_2$(mol%) thin films on soda-lime-silica slide glass and sapphire substrate were obtained by spin-coating technique using tetraethyl orthosilicate and titanium trichloride as starting materials. The prepared film annealed at $750^{\circ}C$ showed a high transmittance and a low reflectance. For the $SiO_2-TiO_2$ films on slide glasses, a strong interaction between the sodium ion and oxygens is properbly the origin of the good stability to the high temperature and the high humidity.

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Prepatation of$(Ba_{0.5}, Sr_{0.5}) Tio_3$thin folms by Laser Ablation technique and their electrical properties with different electrodes (Laser Ablation에 의한 $(Ba_{0.5}, Sr_{0.5}) Tio_3$박막의 제조와 전극에 따른 전기적 특성)

  • Yun, Sun-Gil;Safari, A.
    • Korean Journal of Materials Research
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    • v.4 no.4
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    • pp.401-405
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    • 1994
  • The chemical composition and electrical properties were investigated for epitaxially crystallized $(Ba_{0.5}Sr_{0.5})Tio_3$ (BST) films deposited on Pt and $YBa_Cu_3O_{7-x}$(YBCO) electrodes by laser ablation technique. The crystalline quality of the heteroepitaxial BST films deposited on Pt bottom electrode was found to be better than that of BST film on YBCO electrode by the RBS analysis. Films deposited at $600^{\circ}C$ on Pt electrode showed a dielectric constant of 320 and a dissipation factor of 0.023 at 100kHz. Leakage current density of BST films on Pt electrode was smaller than that on YBCO bottom electrode. Their leakage current density was about 0.8$\mu \; A/ \textrm{cm}^2$ at an applied electric field of 0.15MV/cm.

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Evaluation of Self-cleaning Property by Measuring Brightness of Tio2 Coating Ceramic Tile under Outdoor Exposure Test (옥외폭로시험 Tio2 코팅 세라믹 타일의 명도측정에 의한 방오특성 평가)

  • Shin, Dae-Yong;Kim, Kyung-Nam
    • Journal of the Korean Ceramic Society
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    • v.45 no.6
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    • pp.345-349
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    • 2008
  • $TiO_2$ coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using $TiCl_4$ as a precursor. $TiO_2$ film was formed on the ceramic tile by spray-coating technique and heat-treated at $500^{\circ}C$ for 1 h. The size and crystalline structure of $TiO_2$ particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of $TiO_2$ on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of $TiO_2$ coating tile was affected by the coating amount of $TiO_2$ however, not affected by the UV light intensity included in sun's ray (irradiation direction). $TiO_2$ coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of $TiO_2$ coating tile.

The Effect of $Tio_2$ Addition on the Magnetic Properties of Mn-Zn Ferrites ($Tio_2$첨가가 Mn-Zn Ferrites의 자기적 특성에 미치는 영향)

  • 박종원;한영호
    • Journal of the Korean Magnetics Society
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    • v.9 no.6
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    • pp.278-284
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    • 1999
  • The effect of TiO$_2$addition has been studied on the power loss, density, initial permeability, resistivity, and microstructure of Mn-Zn ferrites. TiO$_2$addition increased the density of sintered body and decreased of the initial permeability. Activation energy for electron hopping as well as electrical resistivity increased with TiO$_2$addition. The toroidal core sintered at 1150 $^{\circ}C$ with 1.5 wt% of TiO$_2$demonstrated the power loss of 83 mW/㎤ at 1 MHz, 25 mT, 8$0^{\circ}C$. However, the same specimen sintered at 120$0^{\circ}C$ lead to the power loss, 1168 mW/㎤ at 1 MHz, 25 mT, 8$0^{\circ}C$ and developed an exaggerated grain growth.

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