• Title/Summary/Keyword: Organic coating

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A Study on the Aging Behavior of Ship Organic Coating by the Flow Induced Shear Stress (유동 전단응력에 의한 선박 유기도막의 열화거동 연구)

  • Park Hyun;Park Jin-Hwan;Ha Hyo-Min;Chun H.H.;Lee In-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.9-14
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    • 2006
  • Analysis has been made of the anti-corrosive property of organic coating under the shear stress of the flow by means of AC impedance method. Marine anti-corrosive painted panels were placed in the water channel with varying flow rate, thereby experiencing varying flow shear stress on the surfaces. The velocities of the salt water were ranged from 1.48 to 5.2 m/s and the coating thickness of from $70{\mu}m\;to\;140{\mu}m$. For all coating thicknesses investigated, the poorer anti-corrosive property and the lower adhesion strength have been found for the higher shear stress. It has been found that the shear stress accelerates the aging of organic marine coatings.

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A Study on the Degradation of Isopropyl Alcohol with $TiO_2-Coated$ Plastic Optic Fibers (광촉매 코팅 광섬유의 IPA 분해 특성 연구)

  • Yu Dong-Sik;Joo Hyun-Ku;Ha Jin-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.4
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    • pp.337-341
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    • 2005
  • The degradation of IPA according to coating conditions was examined by $TiO_2/P-25-coated$ POF. In the photoactivity of $TiO_2-coated$ POF, ethanol solvent was higher activity than other solvents. Inorganic(KR-400), organic(A-9540) and inorganic$\cdot$organic hybrid(GPTMS, TMOS) resins were used as binder. Organic binder(A-9540) showed the highest activity for degradation of IPA, but organic binder was decomposed by $TiO_2$. Inorganic binder had lower binder ability than others, and lower adhesive than organic binders. In TMOS as inorganic · organic hybrid binder, activity of IPA degradation was decreased by addition of TMOS when the ratio of TMOS and P-25 was changed from 0.05 to 1.

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Characteristics of TVOCs Emission Factors from Chemical and Natural Coating Materials (화학 및 천연페인트에서 발생되는 TVOCs의 방출강도 특성 연구)

  • Kim Shin Do;Kim Jeong Ho;Park Jin Soo;Lee Jeong Joo
    • Journal of Environmental Health Sciences
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    • v.30 no.5 s.81
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    • pp.487-492
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    • 2004
  • Building materials are composed of very complex chemical compounds, and these indoor building materials discharge very much Volatile Organic Compounds(VOCs). We performed the environmental chamber test to investigate the Total VOCs(TVOCs) emission characteristics and emission factors about chemical and natural coating materials. As the result, we concluded that TVOCs emission are high at initial time and decreased in course of time. Natural paint was low emission level for TVOCs than chemical paint by small chamber test. The TVOCs emission factor-time profile showed a good fit with the results from the measured and predicted value.

A Study on Properties of PVA/$SiO_2$ Organic-inorganic Hybrid Materials Barrier Layer Coated on Flexible Substrate (PEN)

  • Koo, Tae-Wook;Farva, Umme;Yu, Eric S.H.;Kim, Yun-Su;Park, Chin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.657-659
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    • 2008
  • Barrier coating properties of PVA/$SiO_2$ on the flexible substrates (PEN) have been investigated. Thin layer of PVA/$SiO_2$ organic-inorganic hybrid materials were deposited on PEN substrate by the spin-coating. The optical properties and surface roughness of barrier layer on flexible substrate were characterized by AFM, UV-Vis and WVTR/ OTR.

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Effect of Surface Finishing Materials on the Moisture Conditions in Concrete: Vapor and Water Permeability of Finishing Materials Under Changing Environmental Conditions

  • Ryu, Dong-Woo
    • International Journal of Concrete Structures and Materials
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    • v.2 no.2
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    • pp.83-90
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    • 2008
  • Permeability to vapor and water among other performances required for finishing materials is dealt with in this study. The relative moisture content of concrete coated/covered with a finishing material was experimentally investigated while changing the environmental conditions including temperature, relative humidity, and rainfall. An organic paint (water-based urethane), organic synthetic resin emulsion-type film coating (film coating E), and inorganic porcelain tiles were selected as the finishing materials. When compared from the aspect of vapor and water permeability, the vapor permeability and water permeability of water-based urethane were high and low, respectively; those of film coating E were high and high, respectively; and those of porcelain tiles were low and low, respectively. This means that the moisture state of concrete structures is governed not only by the environmental conditions but also by the performance of finishing materials. It is therefore of paramount importance to appropriately select a finishing material to address the specific deteriorative factors involved in the concrete structure to be finished.

Preparation of tungsten metal film by spin coating method

  • Lee, Kwan-Young;Kim, Hak-Ju;Lee, Jung-Ho;Sohn, Il-Hyun;Hwang, Tae-Jin
    • Korea-Australia Rheology Journal
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    • v.14 no.2
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    • pp.71-76
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    • 2002
  • Metal thin films, which are indispensable constituents of ULSI (Ultra Large Scale Integration) circuits, have been fabricated by physical or chemical methods. However, these methods have a drawback of using expensive high vacuum instruments. In this work, the fabrication of tungsten metal film by spin coating was investigated. First of all, inorganic peroxopolytungstic acid (W-IPA) powder, which is soluble in water, was prepared by dissolving metal tungsten in hydrogen peroxide and by evaporating residual solvent. Then, the solution of W-IPA was mixed with organic solvent, which was spin-coated on wafers. And then, tungsten metal films, were obtained after reduction procedure. By selecting an appropriate organic solvent and irradiating UV, the sheet resistance of the tungsten metal film could be remarkably reduced.

Corrosion Resistance Characteristics of Cr-free Coating Solution for Degraded STS316L (열화한 STS316L에 대한 Cr-free 코팅액의 내식특성)

  • Lee, So-Young;Kim, Young-Soo;Jeong, Hee-Rock;Ahn, Seok-hwan;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.29 no.6
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    • pp.475-480
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    • 2015
  • In this study, we developed a Cr-free organic/inorganic hybrid solution and investigated its coating properties on degraded STS316L. Both the OIBD-1 solution and OIBD-2 solution had excellent corrosion resistance and adhesion ability. However, the solution had some problems in a boiling water environment. In addition, the flexibility was excellent, and the scratch resistance was relatively good.

흡.탈수 반복 환경에 있어서 유기도막의 방식성 평가

  • Park, Jin-Hwan;Lee, Geun-Dae;Jeon, Ho-Hwan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.262-268
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    • 2003
  • Organic coatings are widely used to control the corrosion of steel structure. The water in coatings may cause swelling or solvation of coatings, leading to the degradation of coatings. In addition, water affects the permeation of oxygen and other corrosive agents, and consequently the presence of such substances at coating-metal interface promotes corrosion of metal substrate. In this study, the anticorrosive properties of 4 types of coating, such as epoxy-epoxy, epoxy-urethane, urethane-epoxy, urethane-urethane, were evaluated. The evaluation tests were carried out under cyclic water-absorption/desorption conditions, consisting of alternative exposure to diluted 0.001M-LiCl($a_{1120}{\fallingdotseq}1$) and concentrated l0M-LiCl($a_{1120}{\fallingdotseq}0.05$). The anticorrosive performances of coatings were found to decrease in the order of urethane-urethane> urethane-epoxy> epoxy-epoxy coating.

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Thin layer(Overcoat) for TFT-LCD color filter (LCD용 컬러필터 보호막)

  • Kim, Myeong-Koo;Park, Joo-Hyeon;Lim, Young-Taek
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.273-273
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    • 2006
  • Over the past years, a large number of acrylate polymers have been developed and the overcoat thin layer containing acrylate polymers have been used for TFT-LCD color filter. As forming thin layer using acrylate polymers, the existing acrylate polymers have some problems such as low hardness by low Tg temperature, coating uniformity and solubility in organic solvent. To solve these problems, we synthesized new polymer(Scheme.), containing olefin monomer, which has high Tg temperature, good coating uniformity and good solubility in organic solvent. The overcoat thin layer containing new polymer resulted in good coating uniformity, stain, spot, scratch, heat resistance, DOP(Degree Of Planarization) on RGB glass, transparency, hardness, adhesion, anti-chemicals(anti-acid, anti-base, anti-organic solvent), insulation and anti-humidity. Scheme. The structure of new polymer X = Olefin monomer contains ketone, ester, hydroxy, ether, halogen, nitrile, alkoxy, phenyl functional group $R_1$ and $R_2$= H or $CH_3$. Ratio=0<[1/(1+m+n)]<0.7,0.1[$\leq$[n/(1+m+n)]<0.5.

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PVDF-TiO2 coated microfiltration membranes: preparation and characterization

  • Shon, H.K.;Puntsho, S.;Vigneswaran, S.;Kandasamy, J.;Kim, J.B.;Park, H.J.;Kim, I.S.
    • Membrane and Water Treatment
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    • v.1 no.3
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    • pp.193-206
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    • 2010
  • Organic fouling and biofouling pose a significant challenge to the membrane filtration process. Photocatalysis-membrane hybrid system is a novel idea for reducing these membranes fouling however, when $TiO_2 photocatalyst nanoparticles are used in suspension, catalyst recovery is not only imposes an extra step on the process but also significantly contributes to increased membrane resistance and reduced permeate flux. In this study, $TiO_2$ photocatalyst has been immobilized by coating on the microfiltration (MF) membrane surface to minimize organic and microbial fouling. Nano-sized $TiO_2$ was first synthesized by a sol-gel method. The synthesized $TiO_2$ was coated on a Poly Vinyl Difluoride (PVDF) membrane (MF) surface using spray coating and dip coating techniques to obtain hybrid functional composite membrane. The characteristics of the synthesized photocatalyst and a functional composite membrane were studied using numerous instruments in terms of physical, chemical and electrical properties. In comparison to the clean PVDF membrane, the $TiO_2$ coated MF membrane was found more effective in removing methylene blue (20%) and E-coli (99%).