Class-II-type nanosilica-epoxy hybrid coating with high moisture barrier performance and mechanical robustness

Im, Hyeon-Gyun,Park, Hoy Yul,Kang, Dong Jun Elsevier 2019 Progress in organic coatings Vol.126 No.-

<P><B>Abstract</B></P> <P>We report the development of a class-II-type hybrid coating (NS-EP hybrid) composed of surface-modified nanosilica (NS) as the filler and a thermo-curable epoxy polymer (EP) as the matrix. NS is synthesized using a hydrolytic sol-gel process; its hydroxyl surface is rendered cross-linkable using glycidyl ligands to ensure homogeneous dispersion and optimal hybridization with the EP matrix. The NS-EP hybrid shows high optical transparency, enhanced mechanical properties, and improved moisture barrier performance. Further, we discuss the physical properties of the hybrid with respect to the NS content. To study the applicability of the hybrid as a high-performance barrier material in practical applications, an actual OLED device is encapsulated using the hybrid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We introduce class-II-type high-performance hybrid coating (NS-EP hybrid) composed of a surface-modified nanosilica and a thermo-curable epoxy matrix. </LI> <LI> The NS-EP hybrid exhibits excellet moisture barrier performace as well as robust mechanical property. </LI> <LI> The OLED device is encapsulaed with the NS-EP hybrid coating, and thus shows considerably extended lifetime. </LI> </UL> </P>

Effects of Hybrid Coat on shear bond strength of five cements: an in vitro study

Yue Guo,Hou-De Zhou,Yun-Zhi Feng 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.6

PURPOSE. To evaluate the sealing performance of Hybrid Coat and its influence on the shear bond strength of five dentin surface cements. MATERIALS AND METHODS. Six premolars were pretreated to expose the dentin surface prior to the application of Hybrid Coat. The microscopic characteristics of the dentinal surfaces were examined with scanning electron microscopy (SEM). Then, 40 premolars were sectioned longitudinally, and 80 semi-sections were divided into a control group (untreated) and a study group (treated by Hybrid Coat). Alloy restoration was bonded to the teeth specimen using five different cements. Shear bond strength was measured by the universal testing machine. The fracture patterns and the adhesive interface were observed using a stereomicroscope. RESULTS. SEM revealed that the lumens of dentinal tubules were completely occluded by Hybrid Coat. The Hybrid Coat significantly improved the shear bond strength of resin-modified glass ionomer cement (RMGIC) and resin cement (RC) but weakened the performance of zinc phosphate cement (ZPC), zinc polycarboxylate cement (ZPCC) and glass ionomer cement (GIC). CONCLUSION. Hybrid Coat is an effective dentinal tubule sealant, and therefore its combined use with resin or resin-modified glass ionomer cements can be applied for the prostheses attachment purpose.

콘크리트의 내구성 증진을 위한 코팅재의 성능 평가

김성수 ( Kim Sung-soo ),최춘식 ( Choi Choon-sik ),남용혁 ( Nam Yong-hyuk ) 한국구조물진단유지관리공학회 2003 한국구조물진단유지관리공학회 논문집 Vol.7 No.4

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. Normally coating is used a method for protecting reinforced concrete. For this purpose, organic as well as inorganic coatings are used. The advantages of inorganic coatings are lower absorption of UV, non-burning etc. On the other hand, organic coatings have the advantage of low permeability of CO₂, SO₂ and water. Organic coatings provide better protection for reinforced concrete. However, in organic coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, they have a problem with adhesion. So, we developed coating material, WGS-Eco which was hybridized with polymer and cement based material to protect concrete structures and solve problems of organic coatings. This study was conducted an comparative evaluation on physical and durable performance of developed coating material and previously used coating materials. As a result, the performance of developed coating material was not inferior to organic coating materials. So, the developed coating material was considered as a suitable coating material which had advantages of inorganic and organic coatings for protecting concrete.

졸-겔법에 의한 유,무기 TiO2-SiO2 혼성(Hybrid)코팅재료의 제조 및 부식 특성 평가

노정준 ( J. J. Noh ),맹완영 ( W. Y. Maeng ) 한국부식방식학회(구 한국부식학회) 2015 Corrosion Science and Technology Vol.14 No.2

Single TiO2 coating prepared by sol-gel process usually experiences cracks in coating layer. In order to prevent cracks, an inorganic-organic hybrid TiO2-SiO2 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, γ-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 TiO2-SiO2 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.

Biodegradable poly(lactic acid)-based hybrid coating materials for food packaging films with gas barrier properties

Gree Bang,김성우 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.3

The inclusion of biodegradable poly(lactic acid) (PLA) as an organic component into the inorganic silica networks was attempted to prepare environmentally friendly hybrid coating materials with improved gas barrier properties by using sol–gel method. The PLA film obtained by melt extrusion casting process was used as a substrate for coating with prepared PLA/SiO2 hybrids. Interfacial attraction between the organic and the inorganic phases in the hybrid was promoted by employing 3-isocyanatopropyltriethoxysilane (IPTES) as a silane coupling agent. Phase interaction, morphologies, crystallization behavior, and optical transparencies for the prepared hybrids were investigated not only to evaluate the phase compatibility, but also to present an evidence for the gas permeation behavior through the hybrid coated PLA film. The incorporation of the silica component at appropriate level of content substantially increased the resistance to gas permeation. The films retained high transparency, with optical transmittance of over 92%, and showed oxygen and water vapor barrier properties improved by 69.7%and 45.7%, respectively, over those of neat PLA film. Aging process improved the barrier properties of the hybrid coatings due to created dense network structures.

연소율 제어 로켓 연료 제작을 위한 진동 기반 딥코팅

이정락(Jeongrak Lee),곽현수(Hyunsu Kwak),이병호(Byungho Lee),이안나(Anna Lee) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

This paper proposes a new manufacturing process of propellant controlling the regression rate through vibration-based multi-layer dip coating. This coating method can fabricate a uniform coating surface in a short period compared to a conventional dip coating that produces a non-uniform thickness due to gravity. Our developed propellant can prevent efficiency reduction of propulsion adding the different weight of a powder that affects the regression rate in a layer by layer. Thus, this study analysis factors depending on coating thickness by vibration-based dip coating. The coating thickness profile has an inverse relationship with the applied mechanical energy and is found to be independent of the dipping velocity at which the cylindrical substrate is immersed in a coating solution. Furthermore, the density and viscosity of an outer fluid interacting with the coating solution during a vibration affect the coating thickness at the area parallel to the direction of vibration.

Surface modification of mild steel before acrylic resin coating by hybrid ZnO/GO nanostructures to improve the corrosion protection

Zahra Sharifalhoseini,Mohammad H. Entezari,Ali Davoodi,Mohsen Shahidi 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

The synergistic effect of ZnO and GO nanostructures on the surface modification of mild steel before theacrylic resin coating was studied. Firstly, the steel surface was pretreated in the presence of ultrasonicirradiation, and then ZnO nanostructures were synthesized by the cyclic voltammetry technique. GOnanosheets prepared by the modified hummer’s method were deposited on ZnO-containing surfaces usingtheelectrophoreticdeposition(EPD)technique.GOcoatingswiththicknessesof2.84,4.47and9.42mmwereobtained by varying the EPD time, and the 4.47 mm was found as the optimum value for the fabrication ofhybrid ZnO/GO structures. All samples were then covered with a thin layer of acrylic resin (10 mm) by thespin coating technique. The results indicated that the sample with underneath of hybrid ZnO/GOnanostructures shows significant improvement in anti-corrosion performance. In other words, Rp isincreased from 150,000 V cm2 (in the rein coated sample) to 380,000 V cm2 (in the sample with hybridnanostructures). The resulting surface has the potential to use as protective and glossy black coatings. Theroleof underneathnature,surface roughness, and molecular interactionsbetweenoxygenfunctionalgroupsof ZnO, GO, resin, and the metal in the enhanced corrosion protection was illustrated.

A novel strategy to modify the surface of plasma electrolysis produced inorganic coatings for fabricating organic@functional binding agents@inorganic materials

Al Zoubi, Wail,Ko, Young Gun Elsevier 2019 Journal of Alloys and Compounds Vol.776 No.-

<P><B>Abstract</B></P> <P>Organic@functional binding agents(FBAs)@inorganic materials are fabricated using two efficient methods. For this purpose, inorganic layer containing organically magnesium aluminate loaded with metal hydroxide, namely (Mg(OH)<SUB>2</SUB> or/and Ni(OH)<SUB>2</SUB>), and 2-mercaptobenzimidazole (MBI) were produced on Mg-3%Al-1%Zn alloy via plasma electrolysis (PE) method and then two-step dip chemical coating (DCC) method. The presence of metal hydroxides resulted in a decrease in the porosity and microcracks and an increase in strong bonds between organic and inorganic coating. Thus, it was found that the hybrid 2-mercaptobenzimidazole and metal hydroxides materials act good corrosion inhibitors for magnesium corrosion in aqueous solutions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The functional binding agents are an efficient tool for functionalizing surfaces. </LI> <LI> We combine plasma analysis and two-step dip chemical coating. </LI> <LI> Complexes with organic chains and these chains grow on binding agent surfaces. </LI> <LI> The hybrid materials extraordinarily suppresses metal oxidation and oxygen reduction. </LI> </UL> </P>

하이브리드 코팅 시스템에 의해 합성된 Zr-Al-N 박막의 미세구조와 기계적 특성, 산화 특성, 부식특성

최하송(Hasong Choi),장재호(Jaeho Jang),안은솔(Eunsol An),김광호(Kwang Ho Kim) 한국표면공학회 2013 한국표면공학회지 Vol.46 No.6

Zr-Al-N coatings were synthesized by the hybrid coating system combining arc ion plating and DC magnetron sputtering from a Zr and an Al target in argon-nitrogen atmosphere, respectively. By changing the power applied on the Al cathodes, the Zr-Al-N coatings with various Al contents were deposited. The microstructure and chemical compositions of the Zr-Al-N coatings were studied by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM). With increasing of Al content in the coatings, the solid solution (Zr, Al)N crystallites were observed in the Zr-Al-N coatings. The nanohardness of the Zr-Al-N coatings exhibited a maximum value of 42 GPa for the Zr-Al (7.9 at.%)-N, and decreased with further increase in Al content in the coatings. The oxidation and corrosion behavior of the Zr-Al-N coatings revealed better properties compared than those of ZrN coatings due to the formation of a solid solution.

콜로이드 실리카를 이용한 UV 경화형 친수성 코팅 도막 제조

양준호 ( Jun Ho Yang ),송기창 ( Ki Chang Song ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.6

알코올에 분산된 콜로이드 실리카를 아크릴 단량체인 pentaerythritol triacrylate (PETA)와 혼합시킴에 의해 UV 경화형 친수성 코팅 용액을 제조하였다. 또한 이 친수성 코팅 용액을 PC 기재 위에 스핀코팅 시킨 후 10 min 동안 UV경화시킴에 의해 친수성 코팅 도막이 제조되었다. 이 과정 중 코팅 용액 중의 콜로이드 실리카 양을 10~50 g으로 변화시켜 코팅 도막의 친수성에 미치는 영향을 살펴보았다. 그 결과 코팅 용액 중의 콜로이드 실리카 양은 코팅 도막의 친수성에 큰 영향을 미치며, 콜로이드 실리카 양이 30 g인 경우에 37°의 가장 낮은 접촉각과 H의 우수한 연필경도를 나타내었다. UV-curable hydrophilic coating solutions were prepared by mixing colloidal silica dispersed in alcohol with an acrylic monomer, pentaerythritol triacrylate (PETA). Hydrophilic coating films were also prepared by spin coat-ing the hydrophilic coating solutions on PC substrates and UV curing for 10 minutes subsequently. The effect of the amount of colloidal silica in the coating solutions, which was varied from 10 g to 50 g, was investigated on the hydro-philic properties of UV-cured coating films. The results showed that the amount of colloidal silica had a great influence on the hydrophilic properties of UV-cured coating films and the coating film prepared with 30 g of colloidal silica showed a lowest contact angle of 37° and an excellent pencil hardness of H.