• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.61-62
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• 2011

실리카 나노입자를 분산시킨 기능성 코팅 소재를 개발하였다. 본 기능성 코팅 소재는 마그내슘 판재에 적용하여 내스크래치 및 내부식성을 향상시키기 위한 것이다. 최근 마그네슘 판재는 스마트 폰 및 이동통신 기기의 외장재소재로 각광을 받고 있다. 그러나 표면의 기계적 강도가 약하고, 특히 수분에 의한 부식이 심각하여 사용에 많은 제한을 받고 있다. 본 연구에서는 실리카 나노입자가 분산된 유무기 하이브리드 코팅을 적용하여 기계적 강도 및 내부식성을 향상하고자 하였다. 분산하는 나노입자의 크기를 달리하여 코팅층으로부터 각각 다른 물리적 화학적 특성을 유도할 수 있었다. 각 코팅 층의 특성은 연필경도, 기판 휨 각도, 그리고 electrochemical impedance spectroscopy 등을 이용하여 평가하였고, 최종적으로 휴대폰 신뢰성 평가 기법을 적용하여 상용화 적용성도 평가하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.109-110
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• 2009

실리카와 폴리아닐린의 core-shell 복합체 나노입자를 실리카 나노입자 분산용액을 이용하여 제조하였다. 제조된 복합체 나노입자를 전기변색박막의 소재로 이용하기 위하여 알코올 용액에 분산하였고, 분산된 용액에 Tetraethoxysilane (TEOS)를 소량의 HCl 용액과 함께 첨가하여 코팅 용액을 제조하였다. 코팅 용액을 인듐주석산화물(ITO) 박막이 도포된 유리 기판위에 도포하고 열처리 하여 매우 높은 부착력을 갖는 전기변색박막을 얻을 수 있었다.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.137.2-137
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• 2003

• Polymer Science and Technology
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• v.20 no.2
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• pp.141-149
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• 2009

• Journal of Adhesion and Interface
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• v.21 no.3
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• pp.113-122
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• 2020

Mesoporous materials are a sort of promising materials with a wide spectrum of applications due to their unique well-defined porous structures that provide high surface area and controllable pore size. Among mesoporous materials, periodic mesoporous organosilicas (PMOs) are highly emerging materials in sense of applications due to their large pore sizes and organic functionality in the frame. The organic functional groups in the frameworks of these solids allow tuning of the surface properties and modification of the bulk properties of the material. This article provides a comprehensive overview of PMOs and discusses their different functionalities, morphology and applications, such as catalysis, environmental applications, and adsorption, for which PMOs have been used after their discovery. The review article will provide fundamental understanding of PMOs and their advanced applications to readers.

• Polymer(Korea)
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• v.34 no.5
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• pp.424-429
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• 2010

The hybrid composites of aliphatic polyester-silica were prepared via a sol-gel reaction and their potential application using as a buffer coating layer in the thermoelectric device were investigated. When aliphatic polyesters were thermally treated at a high temperature of $240^{\circ}C$, the polymer showed an increases in thermal degradation temperature by $30{\sim}90^{\circ}C$ according to the thermal treatment time. The polyester-silica composites showed an increases in thermal degradation temperature by $30{\sim}50^{\circ}C$ according to the content of the added silica. Polyester-silica composite showed neither discoloration nor change in optical properties because Knoevenagel condensation reaction was hindered by silica structure. The thermal conductivity of the composites increased linearly according to the content of added silica.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.269-276
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• 2023

In this research works, we propose a hybrid power generation system for drone capable of staying in the air for more than 1 hour. This power system converts the alternating current generated by the generator into direct current through a diode bridge circuit to charge the battery and uses a battery system having separated cells to obtain high controllability of the power system. The fuel efficiency and the power output for individual load were analyzed, and also the performance of a selected generator was studied in this paper. The drone which is equipped with the proposed hybrid power generation system calculated 0.82 ratio for weight vs power output, and flight time of drone showed 4,179 seconds.

• Polymer(Korea)
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• v.32 no.6
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• pp.573-579
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• 2008

PBA/PS core-shell polymer nanoparticles were synthesized by two stage emulsion polymerization and hybridized with silica nanoparticle by simple mixing in emulsion state and following precipitation into water/methanol mixture dissolving $Na_2CO_3$. The stress-strain curve revealed that the elastic modulus was increased with increasing molecular weight of polymer and silica weight fraction but decreased with increasing size of core-shell nanoparticle. Especially, there was a rapid increase of elastic modulus with silica blending. As a result, 6 times higher elastic modulus was observed in PBA/PS core-shell baroplastic sample processed at 25$^\circ$C under 13.8 MPa for 5 min by blending with 13.0 wt% of silica nanoparticle.

• 한국노년학
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• v.29 no.1
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• pp.195-213
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• 2009

The purpose of this study is to analyse how consumption value affects the loyalty of green product through satisfaction and trust among elderly consumers. Data were collected from a cross-sectional survey of 314 older adults (age≥60) in the U. S., who bought and possessed a hybrid car, a representative green product. The statistical methodology is employed a structural equation model. The results demonstrated several important findings. First, perceived social value among elderly population had significant effects on green product satisfaction, while hedonic value did not. Second, both perceived functional value and environment friendly value had a significant positive effect on trust in green products. Third, satisfaction with green products also led to trust in green products. Finally, trust in green products showed their significant effects on loyalty in green product. These results provide practical implications to improve the trust and loyalty in green products among the elderly consumers. Furthermore, by deriving major components of consumption values in green products among the elderly, and analyzing the mechanism of satisfaction, trust, and loyalty, the study emphasizes relationship marketing in implementing "green" marketing strategies.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.292-299
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• 2012

We made 8 wt% silica dispersion system with fumed silica and photo curable acrylic monomer by beads mill process. These dispersions could be applied in organic/inorganic hybrid coating systems. These dispersions could be applied in organic/inorganic hybrid coating systems. The 4 species of photo curable acrylic monomer which was presence of hydroxyl group, different solubility parameter, and different molecular size were used in the silica dispersions. Stability of polar solvent, isopropyl alcohol, in silica dispersions was investigated. We investigated the stability of silica dispersions by using steady-state and dynamic rheology. As the monomer has hydroxyl group increased in mono and binary monomer silica dispersions, they showed non flocculated stable sol (loss modulus (G")> storage modulus (G')). When polar solvent IPA was added into slightly flocculated silica dispersions, they changed to non flocculated stable sol.