• 한국표면공학회지
• /
• 제30권5호
• /
• pp.333-346
• /
• 1997

Plasma spray processes for functional coatings of tubular SOFC ( Soild oxide Fuel Cell).consisting of air electrode, oxide electrolyte, an fuel electrode, are optimized by fully saturated fractional factorial testing. Material and electric characteristics of each coating are analtsed by the implementation of SEM and optical microscope for evaluating microstructure and porosity, X-ray diffraction method for investigating compositional change between raw powder and sprayed coating, and Van der Pauw method for measuring electrical conductivity. LSM ($La_{0.65}Sr_{0.35}MnO_3$air electrode and Ni-YSL fuel electrode coatings have porosities of around 23~30% sufficient for effective fuel and oxidant gas supply to electrochemical reaction interfaces and electrical conductivities of around 90 S/cm and 1000 S/cm, respectively, enough for acting as current collecting electrodes. YSZ($ZrO_2-8mol%Y_2O_3$) electrolyte film has a high ionic conductivities of 0.05~0.07 S/cm at $1000^{\circ}C$ in air atmosphere, but appears to be somewhat too porous to reduce the thickness. for enhancing the cell efficiency. A unit tubular SOFC has beem fabricated by the optimized plasma spray processes for each functional coating and the cell. Its electrochemical chracteristics are investigated by measuring voltage-current and power density with variation of operationg temperature, radio of fuel to air gas flowrates, and total gas flowrate of reactants.

• 한국재료학회지
• /
• 제29권10호
• /
• pp.631-638
• /
• 2019

As automation systems become more common, there is growing interest in functional labeling systems using organic and inorganic hybrid materials. Especially, the demand for thermally and chemically stable labeling paper that can be used in a high temperature environment above $300^{\circ}C$ and a strong acid and base atmosphere is increasing. In this study, a composite coating solution for the development of labeling paper with excellent thermal and chemical stability is prepared by mixing a silica inorganic binder and titanium dioxide. The silica inorganic binder is synthesized using a sol-gel process and mixed with titanium dioxide to improve whiteness at high-temperature. Adhesion between the polyimide substrate and the coating layer is secured and the surface properties of the coating layer, including the thermal and chemical stability, are investigated in detail. The effects of the coating solution dispersion on the surface properties of the coating layer are also analyzed. Finally, it is confirmed that the developed functional labeling paper showed excellent printability.

• Corrosion Science and Technology
• /
• 제11권1호
• /
• pp.15-19
• /
• 2012

Both electrogalvanized and hot-dip galvanized steel sheets have been finally produced via organic-inorganic surface coating process on the zinc surface to enhance corrosion resistance and afford additional functional properties. Recently, POSCO has been developed a variety of chromate-free coated steels that are widely used in household, construction and automotive applications. New organic-inorganic hybrid coating solutions as chromate alternatives are comprised of surface modified silicate with silane coupling agent and inorganic corrosion inhibitors as an aqueous formulation. In this paper we have prepared new type of hybrid coatings and evaluated quality performances such as corrosion resistance, spot weldability, thermal tolerance, and paint adhesion property etc. The electrogalvanized steels with these coating solutions exhibit good anti-corrosion property compared to those of chromate coated steels. Detailed components composition of coating solutions and experimental results suggest that strong binding between organic-inorganic hybrid coating layer and zinc surface plays a key role in the advanced quality performances.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2003년도 추계학술발표회초록집
• /
• pp.59-59
• /
• 2003

In recent, various functional coatings on artificial tooth implants have been conducted to enhance the bonding strength between implants and bones. Despite of these efforts, some previous reports argued that an adhesion strength between titanium implant and the final coatings like hydroxyapatite(HA) is weaker than the strength between coating and bone. In order to increase the adhesion force between the final coating and implant surface, TiN/DLC based functionally graded coating, which has higher mechanical strength than the titanium implant, was applied as a middle layer between titanium implant and final coating. Particularly we finally coated a biocompatible hydroxyapatite film on the DLC layer and examined the mechanical properties. As a result, TiN/DLC based functionally graded coating showed the higher adhesion strength compared with hydroxyapatite single layer coating on the titanium implant.

• Journal of Information Display
• /
• 제13권2호
• /
• pp.91-95
• /
• 2012

Indium phosphide (InP) quantum dots (QDs) are considered alternatives to Cd-containing QDs for application in light-emitting devices. The multishell coating with ZnSe/ZnS was shown to improve the photoluminescence quantum yield (QY) of InP QDs more strongly than the conventional ZnS shell coating. Structural proof for this system was provided by X-ray diffraction and transmission electron microscopy. QY values in the range of 50-70% along with peak widths of 45-50 nm can be routinely achieved, making the optical performance of InP/ZnSe/ZnS QDs comparable to that of Cd-based QDs. The fabrication of a working electroluminescent light-emitting device employing the reported material demonstrated the feasibility of the desired application.

• 한국의류학회지
• /
• 제31권2호
• /
• pp.217-224
• /
• 2007

This paper investigated spring/summer fabric trends of women's and analyzed the correlation between the fabric trends and finishing for 10 years (1995 S/S-2004 S/S). Fabric trend terms were selected from 5 fashion journals and were grouped by hierarchical cluster analysis using SPSS 12.0 statistical package. Also, finishing terms were selected and analyzed by frequency. The results showed that 13 representative fabric trend terms were clean, functional, lustrous, compact, rubbery, comfortable, chic, romantic, decorative, natural, fluid, textured, and ethnic trend. In terms of fabric finishing, 12 representative finishing were selected such as coating, calendaring, wrinkle finishing, decorative finishing, quilting, and washing. Finally, in respect of the analysis of fabric trends and finishing, washing and embroidery were used to represent ethnic trends and textured fabric was closely correlated wrinkle and decorative finishing. Fluid fabrics were expressed via wrinkle and coating and washing and wrinkle were used for natural feeling. Decorative fabric was expressed by embroidery and coating and decorative finishing were frequently used to show romantic and chic fabric. Also comfortable fabrics were correlated with easy care and rubbery, compact, lustrous, and clean fabrics were correlated with coating.

• 펄프종이기술
• /
• 제43권4호
• /
• pp.76-81
• /
• 2011

This study was carried out in order to develop a speciality functional coated paper, which can be recognized under a ultraviolet lamp. The special fluorescent whitening agent (FWA) which absorbs ultraviolet light (397~410 nm) and emits it as yellowish light (570~500nm) was used. The special FWA was applied in a coating color in two ways: (1) direct application to a coating color as a FWA; (2) application on pigment surface, drying it and application it as a fluorescence whitening pigments (colored pigments). The effects of the special FWA on coating color properties were tested and the distribution of colored pigments in coated paper was evaluated under a ultraviolet lamp. The results showed that the colored pigments didn't affect on coating color properties. Experimental results showed the possibility of producing a security coated paper using the special FWA. To produce a speciality functional paper, it was found to be proper to apply the special FWA in the form of colored pigment.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2009년도 추계학술발표대회
• /
• pp.41.1-41.1
• /
• 2009

Aerosol Deposition (AD) is anovel way to fabricate bioactive ceramic coatings in biomedical implants and prostheses applications. In the present work, silicon-substituted hydroxyapatite (HA) coatings on commercially pure titanium were prepared by aerosol deposition using Si-HA powders. The incorporation of silicon in the HA lattice is known to improve the bioactivity of the HA, makingsilicon-substitute HA an attractive alternative to pure HA in biomedical applications. Si-HA powders with the chemical formula $Ca_{10}(PO_4)_6-x(SiO_4)x(OH)_2-x$, having silicon contents up to x=0.5 (1.4 wt%), were synthesized by solid-state reaction of $Ca_2P_2O_7$, $CaCO_3$, and $SiO_2$. The Si-HA powders were characterized by X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), and Fourier transform infrared spectroscopy(FT-IR). The corresponding coatings were also analyzed by XRD, scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results revealed that a single-phase Si-HA was obtained without any secondary phases such as $\alpha$- or $\beta$-tricalcium phosphate (TCP) for both the powders and the coatings.The Si-HA coating was about $5\;{\mu}m$ thick, had a densemicrostructure with no cracks or pores. In addition, the proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 preosteoblast cells grown on the Si-HA coatings were significantly higher than those on the bare Ti and pure HA coating. These results revealed the stimulatory effects induced by siliconsubstitution on the cellular response to the HA coating.

• Journal of Electrochemical Science and Technology
• /
• 제14권3호
• /
• pp.293-300
• /
• 2023

The global energy storage markets have gravitated to high-energy-density and low cost of lithium-ion batteries (LIBs) as the predominant system for energy storage such as electric vehicles (EVs). High-Ni layered oxides are considered promising next-generation cathode materials for LIBs owing to their significant advantages in terms of high energy density. However, the practical application of high-Ni cathodes remains challenging, because of their structural and surface instability. Although extensive studies have been conducted to mitigate these inherent instabilities, a two-step process involving the synthesis of the cathode and a dry/wet coating is essential. This study evaluates a one-step β-Li₂SnO₃ layer coating on the surface of LiNi_0.8Co_0.2O₂ (NC82) via the thermal segregation of Sn owing to the solubility limit with respect to the synthesis temperature. The doping, segregation, and phase transition of Sn were systematically revealed by structural analyses. Moreover, surface-engineered 5 mol% Sn-coated LiNi_0.8Co_0.2O₂ (NC82_Sn5%) exhibited superior capacity retention compared to bare NC82 owing to the stable surface coating layer. Thus, the developed one-step coating method is suitable for improving the properties of high-Ni layered oxide cathode materials for application in LIBs.

• Korean Chemical Engineering Research
• /
• 제51권2호
• /
• pp.285-291
• /
• 2013

Quartz crystal microbalance (QCM)을 기반으로 기체 흡착센서 시스템을 구성하기 위하여 감지물질, 코팅방법, 희석가스 및 온도의 영향 등이 면밀하게 검토되었다. 특히 주요 대기 오염물질로 알려진 $NO_2$와 $SO_2$를 감지할 수 있도록 polypyrrole과 poly(3,4-ethylenedioxythiophene) 고분자 물질이 코팅된 QCM 센서소자를 구성하였으며, 만들어진 센서소자들은 ppm 수준의 농도에서 두 가스에 대한 높은 선택성과 감도를 보였다. 센서소자의 감지특성과 응답속도는 감지물질의 코팅방법과 코팅량에 크게 의존하였다.