• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.421-426
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• 2012

The effect of synthesis conditions such as various organic material and composition of organic-inorganic material in ozone resistance and surface characteristic of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Organic-inorganic hybrid coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 2,2,2-trifluoroethylmethacrylate, and various organic materials with acrylate group, bar-coated on substrates using applicator and densified by UV-curing. It was found that ozone resistance and surface hardness of the coating film was increased with contents of TEOS. It was also found that ozone resistance of coating film was increased with contents of 2,2,2-trifluoroethylmethacrylate. On the other hand, surface hardness was decreased with increase of 2,2,2-trifluoroethylmethacrylate. In addition, Surface hardness of coating film was increased with the addition of aliphatic urethane acrylate. It was also found that the transmittance of coating films was not influenced by content of TEOS and 2,2,2-trifluoroethylmethacrylate. In addition, the coating film exhibited high transmittance of above 90%.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.702-707
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• 2013

High-quality ${\beta}$-silicon carbide (SiC) coatings are expected to prevent the oxidation degradation of carbon fibers in carbon fiber/silicon carbide (C/SiC) composites at high temperature. Uniform and dense ${\beta}$-SiC coatings were deposited on carbon fibers by low-pressure chemical vapor deposition (LP-CVD) using silane ($SiH_4$) and acetylene ($C_2H_2$) as source gases which were carried by hydrogen gas. SiC coating layers with nanometer scale microstructures were obtained by optimization of the processing parameters considering deposition mechanisms. The thickness and morphology of ${\beta}$-SiC coatings can be controlled by adjustment of the amount of source gas flow, the mean velocity of the gas flow, and deposition time. XRD and FE-SEM analyses showed that dense and crack-free ${\beta}$-SiC coating layers are crystallized in ${\beta}$-SiC structure with a thickness of around 2 micrometers depending on the processing parameters. The fine and dense microstructures with micrometer level thickness of the SiC coating layers are anticipated to effectively protect carbon fibers against the oxidation at high-temperatures.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.11
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• pp.44-51
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• 1995

Homogeneous, compositionally graded, and superlattice-like silicon oxynitride(SiON) dielectric layers, with the refractive index varying from 1.46 to 2.05 as a function of film thickness, were grown by computer-controlled plasma-enhanced chemical vapor deposition (PECVD) using silane, nitrogen, and nitrous oxide reactant gases. An antireflection(AR) coating and thin-film electroluminescent(TFEL) devices with multiple dielectrics were designed and fabricated using real time control of reactant gases of the PECVD system.

• Polymer(Korea)
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• v.38 no.5
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• pp.573-579
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• 2014

The effect of synthesis conditions such as carbon nanotube (CNT), 2,2,2-trifluoroethylmethacrylate (3FMA), and composition of organic-inorganic material in ozone resistance and surface characteristics of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 3FMA, various organic materials with acrylate group, and CNT, then bar-coated on substrates using applicator, and densified by UV-curing. It was found that ozone resistance and adhesion of the coating film were strongly dependent upon contents of TEOS, 3FMA, and CNT. Especially, ozone resistance, adhesion, and surface hardness of coating film with CNT were improved, relatively. Ozone resistance of coating film with a high TEOS content was increased, but adhesion was decreased. In addition, it was also found that ozone resistance of coating film was increased with contents of 3FMA. On the other hand, surface hardness was decreased with increase of 3FMA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.151-151
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• 2009

A enameled wire may have better corona-resistance when its coating material contains nano-sized inorganic particles. However, industrial applications are still limited because an aggregation between nanofillers may happen during coating processes. In this study we use a novel scheme of surface modification with silane on silica nanoparticles using sonochemical reaction where composition and surface density of silanes can be controlled in order to reduce particle-particle attractive interaction. Functionalized nanoparticles are evenly dispersed in the matrix confirmed by SEM and energy dispersive x-ray analysis. Dielectric strength and thermal resistance of the nanocomposite wires are improved while flexibility of the wire maintains.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.23 no.2
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• pp.58-69
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• 2014

In case of esthetic restorative procedure with zirconia restoration, we have to use resin cement because of not only just for retention but also esthetic reason. In such a clinical situation, we have to consider two bonding interfaces, one is tooth surface to resin cement and the other is zirconia surface to resin cement. There is well established bonding protocol between tooth surface to resin cement, but bonding protocol of zirconia surface to resin cement is still controversial. In scientific point of view, there are two mechanism for bonding of zirconia restoration.. One is mechanical retention and the other is chemical adhesion. However, we have three different options for bonding of zirconia restoration in clinical situation; 1) Tribo-chemical coating with silica and silane coupling agent 2) Zirconia primer with phosphate chemistry 3) Self-adhesive resin cement with phosphate chemistry.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.168-168
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• 2016

최근 크로메이트 피막의 대체로서 실란 커플링제를 사용한 화성처리가 주목되고 있다. 실란 커플링제는 $R^{\prime}-(CH_2)_n-Si(OR)_3$로 나타내며 OR은 가수분해 가능한 메톡시기, 에톡시기 등의 알콕시기이다. OR기는 가수분해하여 반응성이 높은 시라놀기(-SiOH)를 생성하여 금속표면에 흡착하기 쉽다. 이후, 건조할 때 탈수 축합하여 공유결합이 가능하다. R'는 탄화수소에 한정되지 않고 성질이 다른 원소의 관능기를 나타내며 아미노(amino)기, 글리시딜(glycidyl)기, 멜캅토(melcapto)기, 비닐(vinyl)기를 들 수 있다. 실란 커플링제 가운데 아미노기를 갖는 실란 커플링제는 아연도금 강판을 포함한 다양한 금속의 내식성을 향상시킬 수 있는 화합물의 하나이다. 본 연구에서는 아미노기를 함유한 실란 커플링제에 인산 수용액을 도포하여 수세하지 않고 건조하여 피막을 형성시켰다. 또 부식거동 조사를 목적으로 아미노기를 함유한 실란 커플링제를 사용하여 초산첨가의 경우와 비교하였다.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.767-774
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• 2016

Three different alumina sols were prepared by hydrolyzing aluminum isopropoxide as a starting material in methanol solvent, followed by peptizing with acetic acid, nitric acid or hydrochloric acid as a peptizing agent by the Sol-Gel Method. Also, coating solutions were obtained by adding a silane coupling agent, (3-glycidyloxypropyl) trimethoxysilane to the alumina sols, deposited on polycarbonate substrates by dip-coating and densified by thermal curing. The effect of types of peptizing agents was studied on the properties of coating films. As a result, coating films, prepared with hydrochloric acid or nitric acid as a peptizing agent, showed excellent properties of pencil hardness of H or 2H and adhesion of 5B. On the other hand, coating films, prepared with acetic acid as a peptizing agent, exhibited poor properties of pencil hardness of HB and adhesion of 3B.

• Tribology and Lubricants
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• v.39 no.5
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• pp.190-196
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• 2023

Anti-adhesion coatings are very important in the processing of adhesive materials such as optical clear adhesive (OCA) films. Choosing the appropriate release coating material for dies and tools can be quite challenging. Hydrophobic surface treatment is usually performed, and its performance is often estimated by the static water contact angle (CA). However, the relationship between the release performance and the CA is not well understood. In this study, the water CAs of surfaces coated with anti-adhesion materials and the peel strengths of the acrylic-based adhesive films are evaluated. STC5 and SUS304 are selected as the base materials. Base materials with different surface roughnesses are produced by hairline finishing, mirror-polishing, and end milling. Four fluoropolymer compounds, including a self-assembled monolayer, are selected to make the base surface hydrophobic. Static, advancing, and receding CAs are mostly increased due to the coating, but the CA hysteresis is found to increase or decrease depending on the coating material. The peel strengths all decreased after coating and are largely dependent on the coating material, with significantly lower values observed for fluorosilane and perfluoropolyether silane coatings. The peel strength is observed to correlate better with the static CA and advancing CA than with the receding CA or hysteresis. However, it is not possible to accurately predict the anti-adhesion performance based on water CA alone, as the peel strengths are not fully proportional to the CAs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.388-394
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• 2008

For purpose of anti-static film remaining unchanged in the condition of $160^{\circ}C$, organic solvent, acid and base solution $0.01\sim0.03{\mu}m$ particles of Sb doped tin oxide(ATO) were grafted by 3-Glycidyloxypropyltrimethoxysilane(GPTS) for improving interfere bonding force between ATO and epoxy resin. The particles were dispersed in 2-methoxyethanol with YD-I28(Bisphenol A type epoxy resin, Kukdo chemical) and 1-imidazole as hardener. The anti-static solutions were coated on PI film as thickness of $0.1{\mu}m$. Surface resistivity of anti-static film containing conductive polymer became $10^{12}\Omega/\Box$ after 32 hours in $160^{\circ}C$. The surface resistivity of ATO grafted by GPTS / Epoxy coating layer remained as $10^{7.6}\Omega/\Box$ in $160^{\circ}C$ for 7 days. ATO grafted by GPTS / Epoxy coating layer coated on PI film was dipped in acetone for 7 days. The surface resistivity remained unchanged as $10^{7.6}\Omega/\Box$. The anti-static layer dipped in water solutions containing each KOH 10 wt % and $H_2SO_4$ 2 wt% was ultra-sonicated for 10 minutes per once until 30th. The surface resistance of anti-static layer containing ATO grafted by GPTS remained unchanged.