• Title/Summary/Keyword: gel materials

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A Study on the Reduction of VOCs Generated from Vehicle Interior Parts and Materials Using Visible-light Responsive Photocatalyst (가시광촉매를 이용한 자동차 내장재로부터 발생하는 VOCs의 저감연구)

  • Choi, Sei-Young;Yang, Seung-Gi
    • Elastomers and Composites
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    • v.48 no.3
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    • pp.209-215
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    • 2013
  • On this study, visible-light responsive photocatalyst prepared by sol-gel method was evaluated the effect of the reduction of volatile organic compounds (VOCs) occurred in vehicle interior and its property was examined. According to UV/visible result, visible-light responsive photocatalyst was found that the UV-visible peak is red shift at 420nm, is sensitive in the visible light region. With vehicle interior parts and materials coated visible-light responsive photocatalyst, VOCs was measured by GC/MS. Measuring the VOCs generated from vehicle interior parts and materials, the reduction of VOCs was confirmed.

Fabrication of 3-Dimensional LiMn2O4 Thin Film

  • Park, Bo-Gun;Ryu, Jea Hyeok;Choi, Won Youl;Park, Yong-Joon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.653-656
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    • 2009
  • 3-Dimensionally ordered macroporous $LiMn_2O_4$ thin film was prepared by a sol-gel and dip coating method on Pt/Ti/$SiO_2$/Si substrate. An opal structure consisting of mono dispersed polystyrene beads (300 nm) was used as a template. After solution containing Mn and Li precursors was coated on the template-deposited substrate, the template and organic materials in the precursors was removed by calcination at 400 ${^{\circ}C}$. And then the 3-dimensional $LiMn_2O_4$ thin film with spinel structure was fabricated by heat treatment at 700 ${^{\circ}C}$. The structural and electrochemical property was investigated by XRD, SEM and charge-discharge cycler.

Preparation and Dielectric properties of the Pb(Zr,Ti)$O_3$ Thin Film by Sol-Gel Method (Sol-Gel법에 의한 Pb(Zr,Ti)$O_3$ 박막의 제조 및 유전 특성)

  • Chung, Jang-Ho;Park, In-Gil;Ryu, Ki-Won;Lee, Sung-Gap;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1022-1024
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    • 1995
  • In this study, $Pb(Zr_xTi_{1-x})O_3$(x=0.65, 0.52, 0.35) thin films were fabricated by Sol-Gel method. A stock solution with excess Pb 10[mol.%] of $Pb(Zr_xTi_{1-x})O_3$ was made and spin-coated on the Pt/$SiO_2$/Si substrate at 4000[rpm] for 30[sec.]. Coated specimens were dried on the hot-plate at $400[^{\circ}C]$ for 10[min.]. Sintering temperature and time were $500{\sim}800[^{\circ}C]$ and $1{\sim}60$[min.]. To investigate crystallization condition, PZT thin films were analyzed with sintering temperature, time and composition by the XRD. The microstructure of thin films were investigated by SEM. The ferroelectric perovskite phases precipitated under the sintering of $700[^{\circ}C]$ for 1 hour. In the PZT(52/48) composition, dielectric constant and dielectric loss were 2133, 2.2[%] at room temperature, respectively.

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Fabrication and characterization of CaLa2ZnO5 based nanocrystalline materials

  • Hussain, Sk. Khaja;Raju, G. Seeta Rama;Yu, Jae Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.352.2-352.2
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    • 2016
  • In recent times, much effort has been concentrated on trivalent rare-earth ions activated ceramics or oxide phosphors to develop display industries due to their promising applications in optoelectronic devices and field-emission displays. To prepare efficient phosphors, citrate sol-gel method is one of the best synthetic methods. Green and blue emissive CaLa2ZnO5:RE3+ nanocrystalline materials are synthesized by a citrate sol-gel method. After the samples annealing at $1100^{\circ}C$, morphological and structural properties are investigated by scanning electron microscope images and X-ray diffraction patterns, respectively. At low electron beam voltage of <5 kV, the visible photoluminescence properties are obtained. Various concentrations of the RE3+ ions exhibited their characteristic emission peaks at different excitation wavelengths, respectively. Similarly, at high electron beam anodic voltage, the cathodoluminescence properties are studied as a function of acceleration voltage and filament current. The chromaticity coordinates are calculated for the optimized CaLa2ZnO5 nanocrystalline luminescent materials.

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Electrical Properties of Sol-Gel Derived Ferroelectric Bi3.35Sm0.65Ti3O12 Thin Films

  • Kang, Dong-Kyun;Cho, Tae-Jin;Kim, Byong-Ho
    • Journal of the Korean Ceramic Society
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    • v.42 no.3 s.274
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    • pp.150-154
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    • 2005
  • Ferroelectric $Bi_{3.35}Sm_{0.65}Ti_{3}O_{12}(BSmT)$ thin films were synthesized by sol-gel process. In this experiments, $Bi(TMHD)_{3},\;Sm_{5}(O^{i}Pr)_{13},\;Ti(O^{i}Pr)_4$ were used as precursors, which were dissolved in 2-methoxyethanol. The BSmT thin films were deposited on the Pt/TiO/SiO/Si substrates by spin-coating. Thereafter, the thin films with the thickness of 240 nm were annealed from 600 to $720^{\circ}C$ in oxygen atmosphere for 1 h, and post-annealed in oxygen atmosphere for 1 h after deposition of Pt electrode to enhance the electrical properties. To investigate the effects of Sm-substitution in the BTO thin films, the BTO and BSmT thin films were prepared, respectively. The remanent polarization and coercive voltage of the BSmT thin films annealed at $720^{\circ}C$ were $19.48{\mu}C/cm^2$ and 3.40 V, respectively.

Preparation of Ferroelectric PZT Thin Film by Sol-Gel Processing; (I) Synthesis of Stable PZT Sol Using Chelating Agent and Preparation of Its Thin Film (졸-겔법에 의한 강유전성 PZT 박막의 제조;(I) 킬레이팅 에이전트를 이용한 안정화 PZT 졸의 합성 및 박막의 제조)

  • Kim, Byong-Ho;Hong, Kwon;Cho, Hong-Yeon
    • Journal of the Korean Ceramic Society
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    • v.31 no.7
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    • pp.804-812
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    • 1994
  • Stable PZT coating sol was prepared using chelating agent, ethylacetoacetate(EAcAc) by sol-gel processing under ambient atmosphere. Through FT-IR spectrum analysis on solution of each reaction step, formation of metal complex was confirmed and prepared PZT sol was stable over several months. Through TG-DTA, XRD, FT-IR spetrum analysis of PZT gel powder, it was understood that the addition of EAcAc could reduce the transition temperature to ferroelectric phase, due to the increased homogeneity by matching the hydrolysis and condensation rates by chelation. Single perovskite phase was obtained by the heat-treatment at 54$0^{\circ}C$ for 30 min. The film was coated on ITO-coated glass substrate by dip coating method. After heat-treatment, PZT thin film had thickness in the range of 20~130 nm. The maximum dielectric constant of its thin film at room temperature and 1 kHz was 128.

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Electrooptic Properties of PLZT Thin Films Prepared by Sol-Gel Method (Sol-Gel법으로 제조한 PLZT 박막의 전기광학특성)

  • Lee, Sung-Gap;Chung, Jang-Ho;Bae, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1505-1507
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    • 1996
  • In this study, $(Pb_{0.88}La_{0.12})(Zr_{0.40}Ti_{0.60})O_{2.97}$ (La/Zr/Ti=12/40/60) ceramic thin films were fabricated from an alkoxide-based by Sol-Gel method. PLZT stock solutions were made and spin-coated on the ITO-glass rubstrate at 4000[rpm] for 30[sec]. Coated specimens were baked to remove the organic materials at $400[^{\circ}C]$ for 10[min]. This procedure was repeated 5 times. The coated films were finally annealed at $450{\sim}700[^{\circ}C]$ for 1[hr]. The ferroelectric perovskite phases precipitated under the sintering of $550{\sim}700[^{\circ}C]$ for 1[hr]. Relative dielectric constant of the PLZT thin were increased with increasing the sintering temperature, the thin file sintered at $650[^{\circ}C]$ showed the highest value of 196. But in the PLZT thin film sintered at $700[^{\circ}C]$, relative dielectric constant was greatly decreased due to reacts between ITO electrode and glass substrate. In all thin films, the transmittance was more than 70[%] (at 632.8[nm]).

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The Structural and Electrical Properties of the BST Thin Film Prepared by Sol-Gel method. (Sol-Gel법으로 제조한 BST 박막의 구조 및 전기적 특성)

  • Kim, Kyoung-Duk;Chung, Jang-Ho;Bae, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.291-293
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    • 1997
  • In this study, Sol-Gel derived $(Ba_{0.7}Sr_{0.3})TiO_3$ thin films were fabricated and investigated. The stock solution was synthesized and spin-coated on Pt/Ti/$SiO_2$/Si substrate at 4000(rpm] and then, annealed at $650{\sim}750[^{\circ}C]$. Crystallization condition, microstructural properties and interfacial structure were observed by XRD, AFM, SEM and TEM. It was found that the BST thin films were completely crystallized at 750[$^{\circ}C$] and showed nano-sized grains. The dielectric constant and loss of the BST thin films were 220, 0.01 at 1[kHz] respectively. Increasing the temperature, the dielectric constant and loss characteristics were not varied widely. At the applied voltage of 1.5[V], the leakage current density was under the $10^{-9}[A/cm^2]$.

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