• Title/Summary/Keyword: organic/inorganic hybrid

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Liquid Uptake and Methanol Transport Behaviour of PVDF/SPEEK/TiO2 Hybrid Membrane for DMFC (DMFC용 PVDF/SPEEK/TiO2 하이브리드 막의 수분함량과 메탄올 전이현상)

  • You, Sun-Kyung;Kim, Han-Joo;Park, Soo-Gil
    • Journal of the Korean Electrochemical Society
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    • v.8 no.4
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    • pp.177-180
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    • 2005
  • A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nano particles content. Their liquid uptake, methanol permeability and proton conductivity as a function of inorganic oxide content were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and liquid uptake. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of the morphology, membranes are homogeneous and exhibit a good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with the standard nafion membrane.

Synthesis and Their Properties of (0.8PPV+0.2DMPPV)/Silica Glass, Borosilicate Glass Composites by Sol-Gel Process (Sol-Gel법을 이용한 (0.8PPV+0.2DMPPV)/Silica Glass, Borosilicate Glass 복합체의 합성과 그 특성)

  • 이병우;김병호;윤영권;한원택
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.993-1001
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    • 1997
  • The (0.8PPV+0.2DMPPV) copolymer and silica/borosilicate composites were synthesized by sol-gel process. The organic-inorganic hybrid solution was prepared by using of (0.8PPV+0.2DMPPV) copolymer precursor solution as a raw material for organic components and TEOS and TMB for glass components. Then by drying the solution in vacuum at 5$0^{\circ}C$ for 7days and subsequent heat treatment in vacuum at 15$0^{\circ}C$~30$0^{\circ}C$ for 2h~72h with heating rate of 0.2$^{\circ}C$/min and 1.8$^{\circ}C$/min, the organic-inorganic composites were synthesized. Microstructural evolution of the composites was characterized by DSC, IR spectrocopy, UV/VIS spectroscopy, and TEM. Elimination of the polymer precursor and degradation of the polymer were observed by DSC and Si-O and trans C=C absorption peaks were identified by IR spectra. The polymer was found to be successfully incorporated into the glass matrix and it was confirmed by the absorption peaks from the polymer in the UV/VIS spectra and the TEM results. The absorption peak of the composites was found to shift toward short wavelength side compared to that of the pure polymer and the amount of the blue shift increased with increasing the heat treatment temperature and heat treatment time and with decreasing the heating rate.

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Improving the Corrosion Resistance of Cold-Rolled Carbon Steel by Treatment with a Hybrid Organic/Inorganic Coating Solution (유/무기 하이브리드 코팅액에 의한 냉간압연강판의 내식특성)

  • Kim, Jung-Ryang;Choi, Chang-Min;Nam, Ki-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.4
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    • pp.405-412
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    • 2012
  • In the past, a very popular way to reduce the corrosion rate of zinc was the use of chemical conversion layers based on $Cr^{+6}$. However, the use of chromium salts is now restricted because of environmental protection legislation. Previous research investigated the optimum corrosion resistance of galvanized steel treated with an organic/inorganic solution containing Si. The result showed that the optimum corrosion resistance occurred by heat treatment of $190^{\circ}C$ in 5 min. In this study, one organic and three hybrid organic/inorganic coating solutions were applied to cold-rolled (CR) carbon steel. The coatings were then evaluated for corrosion resistance under a salt spray test. The coating solutions examined in this study consisted of urethane-only, urethane-Si, urethane-Si-Ti, and urethane-Si-Ti-epoxy. The results of the 7 h salt spray test showed that the urethane-Si-Ti and urethane-Si-Ti-epoxy coating solutions had superior corrosion resistance on CR steel.

Corrosion Resistance of Galvanized Steel by Treating Modified Si Organic/Inorganic Hybrid Coating Solution (Si 변성 유/무기 하이브리드 코팅액에 의한 아연도금강판의 내식특성)

  • Seo, Hyun-Soo;Moon, Hee-Joon;Kim, Jung-Ryang;Kim, Jong-Soon;Ahn, Seok-Hwan;Moon, Chang-Kwon;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.25 no.1
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    • pp.32-38
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    • 2011
  • Galvanized steel has gone through a chemical process to keep it from corroding. The steel gets coated in layers of zinc because rust will not attack this protective metal. For countless outdoor, marine, or industrial applications, galvanized steel is an essential fabrication component. The reduction of the corrosion rate of zinc is an important topic. In the past, a very popular way to reduce the corrosion rate of zinc was to use chemical conversion layers based on $Cr^{+6}$. However, a significant problem that has arisen is that the use of chromium salts is now restricted because of environmental protection legislation. Therefore, it is very important to develop new zinc surface treatments that are environmentally friendly to improve the corrosion resistance of zinc and adhesion with a final organic protective layer. In this study, a Urethane solution (only Urethane 20 wt.%; S-700) and an organic/inorganic solution with Si (Si polysilicate 10 wt.% + Urethane 10 wt.%; LRO-317) are used. Based on the salt spray test of 72 h, S-700 and LRO-317 had a superior effect for the corrosion resistance on EGI and HDGI, respectively.

Layered Silicate-Polymer Nanocomposites

  • Jeong, Han-Mo
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.18-18
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    • 2003
  • Natural clays are composed of oxide layers whose thickness is about 1nm and cations existing between the layers. A number of these layers makes primary particles with a height of about 8∼10nm and these primary particles make aggregates with a size of about 0.1∼10$\mu\textrm{m}$. When layered silicate was made to be organophilic, by exchanging the interlayer cations with organic cationic molecules, the matrix polymer can penetrate between the layers to give a nanocomposite, where 1nm-scal clay layers exist separately in a continuous polymer matrix. These nanostructured hybrid organic-inorganic composites have attracted the great interest of researchers over the last 10 years. They exhibit improved performance properties compared with conventional composites, because their unique phase morphology by layer intercalation or exfoliation maximizes interfacial contact between the organic and inorganic phases and enhances interfacial properties. Since the advent of nylon-6/montmorillonite nanocomposite developed by Toyota Motor Co., the studies on layered silicate-polymer nanocomposites have been successfully extended to other polymer systems. They greatly improved the thermal, mechanical, barrier, and even the flame-retardant properties of the polymers.

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Reliability Evaluation of Atomic layer Deposited Polymer / Al2O3 Multilayer Film for Encapsulation and Barrier of OLEDs in High Humidity and Temperature Environments (OLED Barrier와 Encapsulation을 위한 원자층 증착 Polymer / Al2O3 다층 필름의 온습도 신뢰도 평가 분석)

  • Lee, Sayah;Song, Yoon Seog;Kim, Hyun;Ryu, Sang Ouk
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.4
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    • pp.1-4
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    • 2017
  • Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Atomic layer deposition (ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. Moisture permeation has a mechanism to pass through defects, Thin Film Encapsulation using inorganic / organic / inorganic hybrid film has been used as promising technology. $Al_2O_3$ / Polymer / $Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films.

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Effect of Shearing on Crystallization Behavior of Nylon 6/Silver Nanocomposites (전단조건이 나일론 6/은 나노복합소재의 결정화거동에 미치는 영향)

  • Chae, Dong-Wook;Oh, Seong-Geun;Kim, Byoung-Chul
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.321-324
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    • 2002
  • Recently, organic-inorganic nanocomposites have attracted great interest from researchers since they frequently exhibit unexpected hybrid properties synergistically derived from two components[1]. The addition of highly dispersed inorganic nano-sized fillers permits improvement of certain properties of polymers as compared with conventional particulate composites; increase of modulus and strength, improved barrier properties, increase in solvent and heat resistance, and good optical properties[2]. (omitted)

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Preparation of O-I hybrid sols using alkoxysilane-functionalized amphiphilic polymer precursor and their application for hydrophobic coating (알콕시 실란기능화 양친성 고분자 전구체를 이용한 유-무기 하이브리드 졸 제조 및 이를 이용한 발수 코팅)

  • Lee, Dae-Gon;Kim, Nahae;Kim, Hyo Won;Kim, Juyoung
    • Journal of Adhesion and Interface
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    • v.20 no.4
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    • pp.146-154
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    • 2019
  • In this study, alkoxysilane-functionalized amphiphilic polymer (AFAP), which have hydrophilic segment and hydrophobic segment functionalized by alkoxysilane group at the same backbone, was synthesized and used as a dispersant and control agent for reaction rate in the preparation of colloidally stable organic-inorganic (O-I) hybrid sols. After reaction with fluorosilane compounds, fluorinated O-I hybrid sols were prepared and coated onto glass substrate to form hydrophobic O-I hybrid coating films through low-temperature curing process. Surface hardness and hydrophobicity of cured coating films were varied with type of solvent and composition of AFAP and fluorinated alkoxysilane compounds. At appropriate solvent and composition of fluorinated alkoxysilane compounds, O-I hybrid coating film having high transparency and surface hardness could be prepared, which could be applicable to cover window of solar cell and displays.

A Study on Organic-Inorganic Hybrid Sound Absorbing Materials Using by Recycling Gypsum (재활용 석고 부산물을 이용한 유무기 하이브리드 흡음재 개발 연구)

  • Shin, Hyun-Gyoo;Jeon, Bo-Ram;Ha, Joo-Yeon;Jeon, Chan-Soo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.4
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    • pp.481-487
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    • 2017
  • The purpose of this study is to develop the hybrid sound-absorbing materials that is made from organic polyurethane sponge impregnated with inorganic binder solutions. The inorganic slurry which is made from ${\alpha}$-hemihydrate gypsum mixed with 60% water, and various additives including plasticizer are used as binder. The test specimens are prepared and tested for sound absorption performance by the impedance tube methods. From the test results, noise reduction coefficient(NRC) of development materials specimen bound by the inorganic binder slurry is 0.41. They are 2 times or more higher than commercial products specimens bound by organic materials only which have NRC values in the range of 0.14 to 0.28. The polyurethane sponge specimens impregnated with inorganic gypsum slurry binder have a good balance between performance and cost, and have proper properties in density, thermal conductivity, non-combustible, and absence of harmful substances as sound-absorbing internal boards for noise barrier wall. It is apparent that the good sound absorption materials can be produced according to the optimum mix design that is recommended from this study.