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

Inorganic-organic hybrid coating solutions were synthesized using titania sol from titanium isopropoxide (TTIP) as an inorganic component and mixture of two or three types of silane coupling agents, such as methacryloxypropyl trimethoxysilane (MPTMS), aminopropyl triethoxysilane (APS), glycidoxypropyl trimethoxysilane (GPTMS) and vinyltriethoxysilane (VTES) as an organic component. The hard coating films were obtained by spin-coating on the polycarbonate sheets and curing the inorganic-organic hybrid coating solutions. The coating films made from the mixture of two types of silane coupling agents showed poor pencil hardness and adhesion, while those from the mixture of three types of silane coupling agents exhibited an improved pencil hardness of 2H~4H and adhesion of 5B. The refractive indexes of coating films were increased from 1.56 to 1.63 at 550 nm by increasing the content of titania sols from 20 to 30 g.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.69-69
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• 2013

In the area of artificial photosynthesis, particularly for the generation of hydrogen form water, much attention has been paid on organic-inorganic hybrid system. Most of all, a dye/TiO2-combined system has been suggested and its potential utility was well manifested. However, due to its complicated nature of charge interactions in between dye and TiO2 -interface there remains a great challenge to establish the charge-activity relationship, per se light driven charge generation and recombination kinetics with respect to the amount of hydrogen produced. Further complexity of that hybrid system has been witnessed when sacrificial donor and aqueous media are considered. To unveil the operating mechanism on such a dye/TiO2-combined system, we have prepared organic dyes suitable to account for the effect of sacrificial donor as well as water interactions, and prepared the typical dye-grafted TiO2 films to investigate charge-activity relationship. Femtosecond flash photolysis clearly defined the dye effects anchored on to the TiO2 platform. In addition, photodynamic data contemplated well to the dye orientation proposed by the DFT calculations. Recent findings provide fundamental understanding on the dye-grafted TiO2 system and establish a firm background how future dye-sensitized organic-inorganic hybrid system can be designed for the light driven hydrogen generation from water.

• Applied Chemistry for Engineering
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• 제28권6호
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• pp.626-631
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• 2017

Transparent plastic substrates require an improvement in properties such as surface hardness and thermal stability for optical applications. In this study, UV-curable organic/inorganic hybrids were synthesized to improve those properties. In order to make the optimum dispersion of inorganic component into the organic matrix, an in situ synthetic method was applied based on sol-gel reaction. Dispersion of the inorganic component in the organic urethane acrylate matrix was improved by using a proper combination of sol-gel reaction and fast UV-curing resulting in the formation of the transparent coating layer. Various alkoxy silanes were employed to vary both the degree of curing and coating properties of UV-curable organic/inorganic hybrids. UV-cured organic/inorganic hybrid coatings showed an improved surface hardness and thermal resistance depending on the content of inorganic component.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제22권12호
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• pp.1009-1013
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• 2009

In this study, we have been synthesized the dielectric layer using pure organic and organic-inorganic hybrid precursor on flexible substrate for improving of the organic thin film transistors (OTFTs) and, design and fabrication of organic thin-film transistors (OTFTs) using small-molecule organic semiconductors with pentacene as the active layer with record device performance. In this work OTFT test structures fabricated on polymerized substrates were utilized to provide a convenient substrate, gate contact, and gate insulator for the processing and characterization of organic materials and their transistors. By an adhesion development between gate metal and PI substrate, a PI film was treated using $O_2$ and $N_2$ gas. The best peel strength of PI film is 109.07 gf/mm. Also, we have studied the electric characteristics of pentacene field-effect transistors with the polymer gate-dielectrics such as cyclohexane and hybrid (cyclohexane+TEOS). The transistors with cyclohexane gate-dielectric has higher field-effect mobility, $\mu_{FET}=0.84\;cm^2/v_s$, and smaller threshold voltage, $V_T=-6.8\;V$, compared with the transistor with hybrid gate-dielectric.

• Korean Journal of Materials Research
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• 제22권11호
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• pp.604-608
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• 2012

Recently, inorganic-organic hybrid materials have attracted much attention not only for their excellent thermal conductivity but also for their flame retardant properties. In this study, the properties of organic-inorganic hybrid insulating materials using inorganic fillers and polyurethane foam with different foaming conditions have been investigated. The addition of 1.5 wt% water to polyurethane as foaming agent shows the best foaming properties. The pore size was decreased in the foaming body with increasing of the $CaCO_3$ addition. The apparent density and thermal conductivity were increased by increasing the $CaCO_3$ addition. With an increasing amount of $CaCO_3$ powder, the flame retardant property is improved, but the properties of thermal conductivity and apparent density tend to decrease. When the addition of fine particles of $CaCO_3$, the apparent density and thermal conductivity were increased and, also, with the addition of coarse particles over $45{\mu}m$ in size, the apparent density and thermal conductivity were increased as well. In this study, the adding of $CaCO_3$ with average particle size of $27{\mu}m$ led to the lowest thermal conductivity and apparent density. After evaluation with different inorganic fillers, $Mg(OH)_2$ showed the highest thermal conductivity; on the other hand, $CaCO_3$ showed the lowest thermal conductivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제6권4호
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• pp.337-341
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• 2005

The degradation of IPA according to coating conditions was examined by $TiO_2/P-25-coated$ POF. In the photoactivity of $TiO_2-coated$ POF, ethanol solvent was higher activity than other solvents. Inorganic(KR-400), organic(A-9540) and inorganic$\cdot$organic hybrid(GPTMS, TMOS) resins were used as binder. Organic binder(A-9540) showed the highest activity for degradation of IPA, but organic binder was decomposed by $TiO_2$. Inorganic binder had lower binder ability than others, and lower adhesive than organic binders. In TMOS as inorganic · organic hybrid binder, activity of IPA degradation was decreased by addition of TMOS when the ratio of TMOS and P-25 was changed from 0.05 to 1.

• Journal of the Korean Recycled Construction Resources Institute
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• 제7권4호
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• pp.431-437
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• 2019

The purpose of this study is to develop an organic-inorganic hybrid insulation materials which has an economic feasibility of organic level and excellent adiabatic performance and fire stability by impregnating organic materials with inorganic binder solutions. The organic base was commercial polyurethane sponge, and the inorganic binder slurry was prepared by mixing water and additives into recycled gypsum byproducts. As a result of evaluation of the developed materials, it was confirmed that it not only has excellent insulation performance of a thermal conductivity of 0.051 W/mK or less but also it is a semi-non-combustible materials specified in the Ministry of Land, Infrastructure and Transport Notice No. 2015-744. The developed materials can also be controlled for thermal conductivity and flame retardance according to density control during manufacturing process, and thus it can be applied to various insulation materials.

• Proceedings of the Materials Research Society of Korea Conference
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.49.2-49.2
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• 2007

• Transactions on Electrical and Electronic Materials
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• 제3권1호
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• pp.9-13
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• 2002

In this work, the surface of inorganic fillers were modified with some functional groups such as stearic acid, aliphatic long chain, vinylsilane and aminosilane to control the interaction between inorganic fillers and polymer matrix. Ethylene-vinyl acetate copolymers (EVA) with various amount of vinyl-acetate and copolyether-ester elastomer were used as polymer matrix. The addition of inorganic fillers increases flame retardancy, but results in steep drop of electrical and mechanical properties, which may be caused by the defects in the interface between organic/inorganic hybrid composites. The hybrid composites are found to show better mechanical properties and higher volume resistivities as inorganic fillers are well dispersed and have good adhesion with polymer matrix. Also, the most effective type of functional group coated on fillers depends on the chemical structure of polymer.

• Journal of Magnetics
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• 제17권4호
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• pp.261-264
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• 2012

Interfacial properties of 5 nm MgO(001)/7 nm Fe(001)/1.8 nm MgO(001)/t nm Cu-phthalocyanine (CuPc) hybrid multilayers with t = 0, 1, 7, and 10 were investigated by using x-ray photoemission spectroscopy (XPS). Rather sharp interfacial properties were observed in the CuPc films grown on an epitaxial MgO/Fe/MgO(001) trilayer than a MgO/Fe(001) bilayer. This work suggests a new way to improve device performance of organic spintronic devices by utilizing an artificially grown MgO(001) thin layer.