• Corrosion Science and Technology
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• 제22권4호
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• pp.242-251
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• 2023

The electrochemical corrosion behaviors of 304 stainless steels (STSs) with various coatings (organic coating and dry coating) were examined, and their applicability as bipolar plates in polymer electrolyte membrane fuel cells (PEMFCs) was validated. The results showed that the organic-coated samples had a significant decrease in anodic and cathodic current density compared to the uncoated sample. However, an increase in carbon black content in the organic coating or additional heat treatment at 700 ℃ resulted in a decrease in corrosion resistance. In addition, improvements in corrosion resistance achieved by adding TiO₂ powder to the organic coating were found to be limited. In contrast, dry coating with TiC and CrC exhibited higher corrosion potential, significantly lower current density, and reduced contact resistance compared to the organic coatings. Notably, the TiC-coated sample showed a comparatively lower current density and more stable behavior than the CrC-coated sample. Based on a series of experimental results, a thin TiC coating without defects is proposed as a promising surface treatment strategy for STS bipolar plates in PEMFC.

• 한국정밀공학회지
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• 제30권6호
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• pp.584-588
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• 2013

Studies are using a roll forming bar. A bar coating device available for a variety of coating conditions was developed. It is characterized by the bar forward and reverse rotation, fine-tune coating speed, and stripe coating. To determine the characteristics of the equipment, the coating tests under different coating conditions were carried out. As a result of the coating tests, the equipment was confirmed as one of strong candidates for the production tool of organic solar cells. The further production test of organic solar cells through stripe coating is in progress.

• Corrosion Science and Technology
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• 제5권5호
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• pp.177-180
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• 2006

The anticorrosive performance of epoxy coating was examined by using the hygrothermal cyclic test and the degradation mechanism of the coating was investigated by using the AC impedance method. The relationship between the results obtained from different tests was studied. It was revealed that the hygrothermal cyclic test can be used as an effective acceleration test for the degradation of organic coating. It was also found in hygrothermal cyclic test that the epoxy coatings have the resistance to stresses at some extent. The degradation of organic coating seems to be caused by the decrease of resistance of coating and the increase of both capacitance and free volume in the organic coating.

• 펄프종이기술
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• 제44권3호
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• pp.1-8
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• 2012

The effects of several factors including organic pigment blending and calending conditions on the surface and optical properties of coated paper were investigated. When clay and calcium carbonate are blended in the ratio of 7 to 3, highest smoothness and relative sediment volume were obtained. When organic pigments were added to the mixture of clay and calcium carbonate, the relative sediment volume did not changed significantly. However, when organic pigments were added to calcium carbonate, sheet gloss and smoothness were improved, and showed the better results than that obtained from the mixture of organic pigment and clay. When organic pigment is blended with clay, the particles of organic pigment are buried in the packing structure of coating layer. However, the particle shape of calcium carbonate is quite different from that of clay, and the aspect ratio of calcium carbonate is similar to that of organic pigment. Thus organic pigment particles are not buried and improved effectively the physical characteristics of coating layer. When the hollow sphere pigment was blended, opacity and sheet gloss were improved significantly. Even though the coating color applied was reduced, the similar level of opacity was maintained. Also, if particle size and void volume are increased, gloss is improved, because coating layer is easily transformed in calendering. Therefore, even though lower pressure was applied during calendering, the smoothness of surface of coating layer was improved, and the decrease of void volume in coating layer was reduced, and the quality of coated sheet can be improved.

• 한국구조물진단유지관리공학회 논문집
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• 제7권4호
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• pp.99-107
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• 2003

일반적으로 코팅은 철근 콘크리트를 보호하기 위한 방법으로 사용되어 진다. 이러한 목적으로 사용되어지는 코팅에는 무기계 코팅뿐만 아니라 유기계 코팅이 있다. 무기계 코팅의 장점은 낮은 자외선 투과성과 불연성 등이다. 반면, 유기계 코팅의 장점은 이산화탄소, 이산화황 및 물 등의 낮은 투과성이며 무기계 코팅보다 더 우수한 철근 콘크리트 보호성능을 가지고 있다. 그러나 에폭시, 우레탄 및 아크릴과 같은 유기계 코팅은 여러 가지 원인에 의해 장기 접착강도가 감소되고 형성된 코팅 막의 들뜸이 발생된다. 또한 유기계 코팅이 콘크리트의 습한 표면에 적용될 경우 접착의 문제점을 갖고 있다. 따라서, 콘크리트 구조물을 보호하고 유기계 코팅의 문제점을 해결하기 위해 폴리머와 시멘트계 재료를 합성시킨 코팅재(WGS-Eco)를 개발하였다. 본 연구에서는 개발된 코팅재와 이전에 사용되었던 코팅재의 물리 성능 및 내구 성능을 평가하였으며, 그 결과 개발된 코팅재는 유기계 코팅재에 비해 성능이 뒤떨어지지 않았다. 따라서 개발된 코팅재는 유기계와 무기계 코팅의 장점을 갖으면서 콘크리트를 보호하기 위한 적합한 코팅재라고 판단되었다.

• Korean Chemical Engineering Research
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• 제52권3호
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• pp.388-394
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• 2014

출발물질인 TTIP로부터 이산화티탄 졸을 합성하여 무기물로 사용하고 유기물로서 실란커플링제인 methacryloxypropyl trimethoxysilane (MPTMS), aminopropyl triethoxysilane (APS), glycidoxypropyl trimethoxysilane (GPTMS), vinyltriethoxysilane (VTES)을 2종 혹은 3종씩 복합 사용하여 유-무기 하이브리드 코팅 용액을 제조하였다. 그 후 코팅 용액을 기재인 PC시트 위에 스핀 코팅시키고, 열경화 시켜 하드코팅 막을 제조하였다. 2종 실란커플링제를 혼합하여 제조된 코팅 막들은 기재와의 부착력과 연필경도가 우수하지 못했으나, 3종 실란커플링제를 혼합하여 제조한 코팅 막은 2H~4H의 향상된 연필경도와 5B의 우수한 부착력을 나타내었다. 이산화티탄 졸의 첨가량이 20 g인 코팅 막의 굴절률은 550 nm에서 1.56을 나타내었으나 이산화티탄 졸의 첨가량을 20 g에서 30 g으로 증가시킨 경우, 코팅 막의 굴절률이 1.63으로 향상되었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.194.2-194.2
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• 2016

Magnesium has many desirable properties of which the high strength/weight ratio makes it extremely valuable in automobile and aerospace industry. However, the high corrosion susceptibility of magnesium and its alloys has greatly limited their large scale use for various applications. Organic coating is one of the most effective ways to prevent magnesium alloys from corrosion. An organic coating is normally used in the final stage of a coating process. It can enhance corrosion resistance of magnesium and its alloys. Organic coating involves a variety of process such as painting, powder coating, cathodic electrocoating (E-painting) and the application of lacquers, enamel and varnishes.

• 한국재료학회지
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• 제17권2호
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• pp.86-90
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• 2007

The organic-capped Ba-Ti-O nanolayers were coated uniformly on spherical Ni particles for multilayer ceramic capacitor (MLCC) applications via the formation of Ti-hydroxide nano-coating layers and their subsequent reaction with Ba-stearate at $180^{\circ}C$. The capping of organic shell on oxide coating layer changed the hydrophilic surface structure into hydrophobic one, which significantly improved the dispersion behavior in hydrophobic solvents such as terpineol and butanol. In addition, the uniform coating of Ba-Ti-O layer was advantageous to prevent Ni oxidation. This method provides a useful chemical route to fabricate organic-soluble Ba-Ti-O coated Ni particles for a highly integrated passive component.

• Corrosion Science and Technology
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• 제14권2호
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• pp.64-75
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• 2015

Single $TiO_2$ coating prepared by sol-gel process usually experiences cracks in coating layer. In order to prevent cracks, an inorganic-organic hybrid $TiO_2-SiO_2$ coating was synthesized by combining precursors with an organic functional group. Five different coatings with various ratios of (1:8, 1:4, 1:1, 1:0.25 and 1:0.125) titanium alkoxide (TBOT, Tetrabutylorthotitanate) to organo-alkoxysilane (MAPTS, ${\gamma}$-Methacryloxy propyltrimethoxysilane) on carbon steel substrate were made by sol-gel dip coating. The prepared coatings were analyzed to study the coating properties (surface crack, thickness, composition) by scanning electron microscope (SEM), focused ion beam (FIB), and Fourier transform infrared spectroscopy (FT-IR). Potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) were also performed to evaluate the corrosion characteristics of the coatings. Crack free $TiO_2-SiO_2$ hybrid coatings were prepared with the optimization of the ratio of TBOT to MAPTS. The corrosion rates were significantly decreased in the coatings for the optimized precursor ratio without cracks.

• Korean Chemical Engineering Research
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• 제50권3호
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• pp.421-426
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• 2012

불소계 아크릴레이트 2,2,2-trifluoroethylmethacrylate을 사용한 자외선 경화형 유-무기 하이브리드 코팅 막에 있어서 무기물 및 사용되는 유기 단량체의 종류 및 조성이 내 오존성 및 표면 특성에 미치는 영향에 대해 연구하였다. 코팅액은 금속 알콕사이드인 tetraethoxysilane(TEOS)와 실란 커플링제인 methacryloyloxypropyltrimethoxysilane(MPTMS)로 구성된 유-무기 혼성 용액에 2,2,2-trifluoroethylmethacrylate와 자외선 경화를 위한 유기물을 첨가하여 제조되었다. 코팅막은 코팅액을 기재위에 바 코팅 한 후 자외선 경화를 통해 제조되었다. 제조된 코팅 막의 내 오존성은 TEOS의 함량이 증가할수록 내 오존성과 표면경도는 향상되었다. 또한, 불소 함량이 증가할수록 내 오존성은 향상되었지만 표면 경도는 다소 떨어졌다. 우레탄 아크릴레이트를 첨가한 코팅 막은 높은 연필경도를 나타내었다. 코팅 막의 투과도는 TEOS와 2,2,2-trifluoroethylmethacrylate의 함량에 큰 영향을 받지 않았다. 더욱이, 코팅 막은 90% 이상의 높은 투과도를 나타내었다.