• Journal of Surface Science and Engineering
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• v.30 no.6
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• pp.382-390
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• 1997

Good appearance of insulation coating is required for non-oriented silicon steel sheets, The property is influenced by both the chemical composition of coating solution and the species of resin. The composition of inorganic-organic coating was studied to obtain good surface quality for non-oriented silicon steel. The greenish degree of coating surface depended on $Cr^{3+}$ content in the coating layer, which was satisfied when chromate content was more than 54.60 wt. %, in the coating solution. The homogeneous pattern and roughness of the coating surface depended on spreading property of the resin. Surface appearance of the coating could be improved by using resin with good spreading property at the chemical composition of chromate 59.00 wt.%.. resin 34.23wt.%, and etyhylene glycol 6.67 wt.% without colloidal sillica.

• Composites Research
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• v.35 no.3
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• pp.121-126
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• 2022

Owing to advantages of polymeric materials for hydrogen tank liner like light-weight property and high specific strength, polymer based composites have gained much attention. Despite of many benefits, polymeric materials for fuel cell tank cause problems which is critical to applications as low gas barrier property, and poor processability when adding fillers. For these reasons, improving gas barrier property of polymer composites is required to study for expanding application fields. This work presents impermeable polymer nanocomposites by introducing thin barrier coating using layer by layer (LBL) deposition method. Also, bi-layered and quad-layered nanocomposites were fabricated and compared for identifying relationship between deposition step and gas barrier property. Reduction in gas permeability was observed without interrupting mechanical property and processability. It is discussed that proper coating conditions were suggested when different coating materials and deposition steps were applied. We investigated morphology, gas barrier property and mechanical properties of fabricated nanocomposites by FE-SEM, Oxygen permeation analyzer, UTM, respectively. In addition, we revealed the mechanism of barrier performance of LBL coating using materials which have high aspect ratio.

• Journal of the Korean Ceramic Society
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• v.45 no.6
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• pp.345-349
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• 2008

$TiO_2$ coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using $TiCl_4$ as a precursor. $TiO_2$ film was formed on the ceramic tile by spray-coating technique and heat-treated at $500^{\circ}C$ for 1 h. The size and crystalline structure of $TiO_2$ particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of $TiO_2$ on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of $TiO_2$ coating tile was affected by the coating amount of $TiO_2$ however, not affected by the UV light intensity included in sun's ray (irradiation direction). $TiO_2$ coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of $TiO_2$ coating tile.

• Corrosion Science and Technology
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• v.8 no.3
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• pp.103-109
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• 2009

An epoxy coating was designed to give a hydrophobic property on its surface by modifying it with three types of Amino Terminated Polydimethylsiloxane (ATP), and then effects of the modification on the structure, surface hydrophobic tendency, water transport behavior and hence corrosion protectiveness of the modified epoxy coating were examined using FT-IR spectroscopy, hydrothermal cyclic test, and impedance test. The surface of epoxy coating was changed from hydrophilic to hydrophobic property due primarily to a phase separation tendency between epoxy and modifier by the modification. The phase separation tendency is more appreciable when modified by ATP with higher molecular weight ATP at higher content. Water transport behavior of the modified epoxy coating decreased more in that with higher hydrophobic surface property. The resistance to localized corrosion of the modified epoxy coated carbon steel was well agreed with its water transport behavior and hydrophobic tendency.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.571-576
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• 1999

This paper describes both electromagnetic properties and electromagnetic-wave absorbind (EMA) characteristics of the radar absorbing coating materials in the microwave frequencies. The coating materials are prepared by mixing ferrite powder with epoxy resin polymers. The electromagnetic property and the EMA characteristics of the coating materials are measured in the frequency ranges between 0.2 GHz and 15GHz using the S-parameter method. The results show that the typical coating material has ({{{{ {μ }`_{r } ^{' } }} of about 2 and ({{{{ { ε}`_{r } ^{' } }} of about 4. And the coating materials have a little EMA characteristics in the frequency from 4 to 6 GHz and more improved EMA characteristics around 12 GHz And it is desirable for improvement of the EMA characteristics of the coating materials to properly select electromagnetic properties of constitutional materials inthe interesting frequency ranges.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.58-67
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• 2006

The relationship between acoustic property and coating hardness of musical instruments was investigated using a sound level meter and a pendulum hardness tester. Urethane topcoat, oil stain, natural oil varnish, and UV-curable epoxy acrylate coatings were applied on four different substrates: Paulownia coreana, Pinus koraiensis, Castanea crenata var. dulcis and Pinus densiflora. The influence of the coating type on the acoustic properties was stronger than that of the substrate. In the case of an oil stain formed with tacky coating layer, the sound pressure level (SPL) and surface hardness decreased with increasing of coating thickness. In the other coatings, SPL decreased and hardness increased as the coating layer thickened. However, SPL began to increase again at coating thickness above $100{\mu}m$.

• Corrosion Science and Technology
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• v.13 no.5
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• pp.170-177
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• 2014

Polyurethane coating was designed to give a hydrophobic property on its surface by modifying it with hydroxyl terminated polydimethylsiloxane and then effects of surface hydrophobic tendency, water transport behavior and hence corrosion protectiveness of the modified polyurethane coating were examined using FT-IR/ATR spectroscopy, contact angle measurement and electrochemical impedance test. As results, the surface of polyurethane coating was changed from hydrophilic to hydrophobic property due primarily to a phase separation tendency between polyurethane and modifier by the modification. The phase separation tendency is more appreciable when modified by polydimethylsiloxane with higher content. Water transport behavior of the modified polyurethane coating decreased more in that with higher hydrophobic surface property. The decrease in the impedance modulus ${\mid}Z{\mid}$ at low frequency region in immersion test for polyurethane coatings was associated with the water transport behavior and surface hydrophobic properties of modified polyurethane coatings. The corrosion protectiveness of the modified polyurethane coated carbon steel generally increased with an increase in the modifier content, confirming that corrosion protectiveness of the modified polyurethane coating is well agreed with its water transport behavior.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.499-504
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• 2006

To improve the quality of coating paper, many areas, such as the manufacturing process of inorganic pigment for the coating, the property change of coating color, the surface design of coating pigment and the productivity of coated paper, were studied. In this study the physical properties and printability of coated paper were compared with the coating pigment to modify the surface of large particle and the coating pigment to mix together the large and small particles. After the coating color was mixed under the same conditions in order that the coating color has the same printability, the printability change caused by the surface modification of coating color was investigated. With the surface SEM of coated paper, the efficiency of the surface modification of coating pigment was investigated. The physical property and printability of coated paper, in addition to the physical properties of coating color, were compared and evaluated. Also, the efficiency of printability was evaluated, changing the mixing condition.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.163-170
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• 2016

In order to improve the hydrophilic property of polymer films, coating solutions which showed a good hydrophilic property, were prepared by the sol-gel method. The coating solutions were prepared by adding different types of silane coupling agents (aminosilane, epoxysilane and acrylsilane) to a colloidal silica (15 nm diameter). The solutions prepared by adding aminosilane resulted in gels which could not be used as coating solutions. On the other hand, the coating solutions prepared by the addition of epoxysilane showed contact angles of $10{\sim}15^{\circ}$ and good hydrophilic property at R=0.10~0.15 (R=silane coupling agent/colloidal silica weight ratio). In addition, the coating solutions prepared by the addition of acrylsilane at R=0.03~0.07, exhibited contact angles of $5{\sim}10^{\circ}$, which means better hydrophilic property than aminosilane or epoxysilane.

• Corrosion Science and Technology
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• v.11 no.1
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• pp.15-19
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• 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.