• Title/Summary/Keyword: coating properties

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Anticorrosion Coatings Obtained by Plasma Electrolytic Oxidation on Implant Metals and Alloys

  • Sinebryukhov, S.L.;Gnedenkov, S.V.;Khrisanfova, O.A.;Puz', A.V.;Egorkin, V.S.;Zavidnaya, A.G.
    • Corrosion Science and Technology
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    • v.17 no.3
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    • pp.91-100
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    • 2018
  • Development of biodegradable implants for treatment of complex bone fractures has recently become one of the priority areas in biomedical materials research. Multifunctional corrosion resistant and bioactive coatings containing hydroxyapatite $Ca_{10}(PO_4)_6(OH)_2$ and magnesium oxide MgO were obtained on Mg-Mn-Ce magnesium alloy by plasma electrolytic oxidation. The phase and elemental composition, morphology, and anticorrosion properties of the coatings were investigated by scanning electron microscopy, energy dispersive spectroscopy, potentiodynamic polarization, and electrochemical impedance spectroscopy. The PEO-layers were post-treated using superdispersed polytetrafluoroethylene powder. The duplex treatment considerably reduced the corrosion rate (>4 orders of magnitude) of the magnesium alloy. The use of composite coatings in inducing bioactivity and controlling the corrosion degradation of resorbable Mg implants are considered promising. We also applied the plasma electrolytic oxidation method for the formation of the composite bioinert coatings on the titanium nickelide surface in order to improve its electrochemical properties and to change the morphological structure. It was shown that formed coatings significantly reduced the quantity of nickel ions released into the organism.

Influence of Thermal Aging on the Properties of Polyurethane Coating of Waterproof. (우레탄 도막 방수재의 열열화 특성)

  • Kim, Sung-Rae;Shin, Hong-Chol;Shin, Ju-Jae;Kim, Young-Geun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.931-934
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    • 2008
  • Polyurethane apply to the waterproof widely. Polyurethane rubbers are prepared that the influences of a thermal aging on the properties are investigated. Polyol and Polyisocyanate were varied ratio in the range mixed by using individual product that was vulcanized by a hot. The waterproofs of Polyurethane were investigated about tensile strength, tear strength and elongation after the thermal Aging for 168, 336, 504 hrs at 70$^{\circ}$C and 80$^{\circ}$C in the air oven. As the increase of the thermal aging time, tensile strength, tear strength and elongation were reduced.

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Blocking Layers Deposited on TCO Substrate and Their Effects on Photovoltaic Properties in Dye-Sensitized Solar Cells

  • Yoo, Beom-Hin;Kim, Kyung-Kon;Lee, Doh-Kwon;Kim, Hong-Gon;Kim, Bong-Soo;Park, Nam-Gyu;Ko, Min-Jae
    • Journal of Electrochemical Science and Technology
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    • v.2 no.2
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    • pp.68-75
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    • 2011
  • In this review, we have investigated the effect of $TiO_2$-based blocking layers (t-BLs), deposited on a transparent conductive oxide (TCO)-coated glass substrate, on the photovoltaic performance of dye-sensitized solar cells (DSSCs). The t-BL was deposited using spin-coating or sputtering technique, and its thicknesses were varied to study the influence of the thin $TiO_2$ layer in between transparent conducting glass and nanocrystalline $TiO_2$ (nc-$TiO_2$). The DSSC with the t-BL showed the improved adhesion and the suppressed charge recombination at a TCO glass substrate than those without the t-BL, which led to the higher conversion efficiency.

Improvement of surface insulation properties of engineering thermoplastics by using nano/micro composite (나노/마이크로 컴포지트를 이용한 엔지니어링 열가소성 플라스틱의 표면 절연 개선)

  • Jung, Eui-Hwan;Lim, Kee-Joe;Hur, Jun;Jeong, Jong-Hun;Kim, Pyung-Jung;Jeong, Su-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.29-29
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    • 2010
  • Engineering plastics have excellent electrical properties, mechanical strength and various characteristic which include chemical resistance, environmental resistance, weatherability at a wide temperature range. It has good characteristic(light weight, good productivity) as compare with epoxy or porcelain insulators. However, engineering plastics not suited to outdoor insulator because it isn't hydrophobic. Therefore, to over come these critical problems, we improve the surface insulation characteristics of engineering plastic by coating micro-, nano- size inorganic fillers added to RTV-SIR(Room temperature vulcanized-silicone rubber) at this plastic surface. The effect is analyzed through salt-fog test, tracking test. In conclusion, the engineering plastic coated RTV with micro-$Al_2O_3$20[phr], nano-Al(OH)3 1 ~ 3[phr] improved much better than the others.

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Fabrication and Characterization of Carbon Nanotube/Carbon Fiber/Polycarbonate Multiscale Hybrid Composites

  • Cho, Beom-Gon;Hwang, Sang-Ha;Park, Young-Bin
    • Composites Research
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    • v.29 no.5
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    • pp.269-275
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    • 2016
  • Multiscale hybrid composites, which consist of polymeric resins, microscale fibers and nanoscale reinforcements, have drawn significant attention in the field of advanced, high-performance materials. Despite their advantages, multiscale hybrid composites show challenges associated with nanomaterial dispersion, viscosity, interfacial bonding and load transfer, and orientation control. In this paper, carbon nanotube(CNT)/carbon fiber(CF)/polycarbonate(PC) multiscale hybrid composite were fabricated by a solution process to overcome the difficulties associated with controlling the melt viscosity of thermoplastic resins. The dependence of CNT loading was studied by varying the method to add CNTs, i.e., impregnation of CF with CNT/PC/solvent solution and impregnation of CNT-coated CF with PC/solvent solution. In addition, hybrid composites were fabricated through surfactant-aided CNT dispersion followed by vacuum filtration. The morphologies of the surfaces of hybrid composites, as analyzed by scanning electron microscopy, revealed the quality of PC impregnation depends on the processing method. Dynamic mechanical analysis was performed to evaluate their mechanical performance. It was analyzed that if the position of the value of tan ${\delta}$ is closer to the ideal line, the adhesion between polymer and carbon fiber is stronger. The effect of mechanical interlocking has a great influence on the dynamic mechanical properties of the composites with CNT-coated CF, which indicates that coating CF with CNTs is a suitable method to fabricate CNT/CF/PC hybrid composites.

Thermal performance evaluation of Temperable Low-e glass window through Heating Energy consumption Analysis (난방에너지 사용량 분석을 통한 후강화 로이유리 창호의 단열성능 평가)

  • Jang, Cheol-Yong;Kim, Jeong-Gook;Ahn, Byung-Lip;Kim, Jun-Sup;Haan, Chan-Hoon
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.200-205
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    • 2012
  • In the high oil price age, intensification of energy efficiency promotion in the building sector is required. Windows are dominating in large percent of whole building loads, and are regarding as the primary target of energy efficiency. In this study, in order to reduce heat loss of buildings, we investigate the thermal performance properties of Temperable Low-e glazing coated Ag membrane that has high electrical conductivity. The Temperable Low-e glazing windows has high insulation and shading properties, and it has strength that can supply various product which consumers want. In order to evaluate thermal performance of temperable windows, we install single low-e windows and double low-e windows in the experimental chamber and analysis the comparison heating energy consumption between single and double Low-e glazing windows. performance evaluation was conducted.

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Studies on the Absorption Behavior of Dye and Pigment Ink for Ink-Jet Printing (잉크제트용 염료잉크와 안료잉크의 흡수거동에 관한 연구)

  • Lee, Hee-Myung;Lee, Yong-Kyu
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.2 s.110
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    • pp.47-56
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    • 2005
  • In technology of ink-jet coating, Image quality from correlation between paper and ink depends on the properties of printer and ink as well as those of paper material. Generally, According to the quality of ink that consists of colorants from 5 to 20 percent, It seems that absorption behavior of each ink is different. In this study, we studied to estimate the effects of dye and pigment ink on the absorption and printing properties using 2-type papers on the market and 3-type silica-based coated papers whose pore structure is different. Using the theory of contact angle to evaluate the absorption property, it was possible to measure the baseline length between paper and ink, volume of droplet as well as contact angle. Also, It was possible to calculate wetting energy(mN/m) and spreading coefficient(mN/m) using the surface tension of each ink. These measurements were available to estimate ink-jet qualities.

Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(III) - Effects of types of base paper and surface treatments on physical properties of the base paper for water resistant corrugated board - (농산물 저온유통용 내수 골판지 상자의 제조(제3보) -원지의 종류와 표면처리 방법에 따른 내수 골판지 원지의 물성-)

  • Jo Jung-Yeon;Min Choon-Ki;Shin Jun-Seop
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.2 s.110
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    • pp.70-77
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    • 2005
  • For the purpose of developing liner board for water resistant corrugated board in the cold chain system, several types of base paper for corrugated board were purchased from the market and 6 different boards were produced in the mill by applying the chemicals, chosen in the previous studies, on the base paper. Then water-moisture resistance and physical properties of the boards were compared each other. The liner board which is dried at high temperature with pressure by Condebelt (CK paper) showed a superior performance in strength over common liner boards. Strength of the board increased by surface chemical treatment up to $60\%$ of compressive strength and $30\%$ of burst strength. Starch insolubilization with Ammonium Zirconium Carbonate and surface coating with a surface sizing agent and a moisture resistant chemical on CK paper showed the best result. Therefore this method was recommended to produce the outer liner board for water resistant corrugated board.

Preparatio and properties of the paraelectric PLT thin film for the cpapcitor dielectrics of ULSI DRAM (ULSI DRAM의 캐패시터 절연막을 위한 Paraelectric PLT 박막의 제작과 특성)

  • 강성준;윤영섭
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.8
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    • pp.78-85
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    • 1995
  • We fabricated the Pb$_{1-0.28{\alpha}}La_{0.28}TiO_{3}$ (PLT(28)) thin film successfully by using the sol-gel method and characterized it to evaluate its potential for being utilized as the capacitor dielectrics of ULSI DRAMs. In our sol-gel process, the acetates were used as the starting materials. Through the TGA-DTA analysis, we established the excellent fabrication conditions of the sol-gel method for the PLT(28) thin film. We obtained the dense and crack-free PLT(28) thin film of 100% perovskite phase by drying at 350$^{\circ}C$ after each coating and final annealing at 650$^{\circ}C$. Its electrical properties were measured from the planar capacitors fabricated on the Pt/Ti/SiO$_{2}$/Si substrate. By the P-E hysteresis measurement, its paraelectric phase was identified and its dielectric constant and leakage current density were measured as 936 and 1.1${\mu}A/cm^{2}$, respectively. Those electrical values indicate that the PLT(28) thin film is the most successful candidate for the capacitor dielectrics of ULSI DRAMs at the present.

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Effect of PEO Process Conditions on Oxidized Surface Properties of Mg alloy, AZ31 and AZ91. I. Applied Voltage and Time (PEO 처리조건에 따른 마그네슘 합금 AZ31과 AZ91의 산화표면피막특성에 대한 연구. I. 전압과 시간의 영향)

  • Ham, Jae-Ho;Jeon, Min-Seok;Kim, Yong-Nam;Shin, Min Chul;Kim, Kwang Youp;Kim, Bae-Yeon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.4
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    • pp.218-224
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    • 2016
  • The surface of Mg alloy, AZ31 and AZ91, were treated by PEO (plasma electrolytic oxidation) in Na-P system electrolyte, with different applied voltage and time. Thickness, roughness and X-ray crystallographic analysis revealed several results. The more applied time and voltage of PEO treated, the thicker oxidized surface coating layer were covered. And surface roughness increased with the thickness of oxidized layer. It was thought that when oxide layer grew, resistivity and breakdown voltage increased with the thickness of layer, and then, the energy of micro plasma need to be higher then before. So, it made craters and pores of surface become greater, which were responsible for the coarse surface.