• Title/Summary/Keyword: polymer materials

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Versatile Strategies for Fabricating Polymer Nanomaterials with Controlled Size and Morphology

  • Yoon, Hyeon-Seok;Choi, Moon-Jung;Lee, Kyung-Jin;Jang, Jyong-Sik
    • Macromolecular Research
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    • v.16 no.2
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    • pp.85-102
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    • 2008
  • The development of reliable synthetic routes to polymer nanomaterials with well-defined size and morphology is a critical research topic in contemporary materials science. The ability to generate nanometer-sized polymer materials can offer unprecedented, interesting insights into the physical and chemical properties of the corresponding materials. In addition, control over shape and geometry of polymer nanoparticles affords versatile polymer nanostructures, encompassing nanospheres, core-shell nanoparticles, hollow nanoparticles, nanorods/fibers, nanotubes, and nanoporous materials. This review summarizes a diverse range of synthetic methods (broadly, hard template synthesis, soft template synthesis, and template-free synthesis) for fabricating polymer nanomaterials. The basic concepts and significant issues with respect to the synthetic strategies and tools are briefly introduced, and the examples of some of the outstanding research are highlighted. Our aim is to present a comprehensive review of research activities that concentrate on fabrication of various kinds of polymer nanoparticles.

PMM for Surface Treatment of Concrete with the Utilization of By-Products

  • Drochytka, Rostislav;Zizkova, Nikol
    • International Journal of Concrete Structures and Materials
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    • v.2 no.1
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    • pp.49-55
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    • 2008
  • The disadvantage of PMM's (polymer-modified mortars) that are currently on the market is the utilization of expensive polymer additives and also the cost of the other components. One of the possibilities how to decrease this price is the effective utilization of waste materials which are very inexpensive in spite of their good properties. The combinations of different degree in polymer adhesiveness and waste secondary raw materials - fly ash - are experimentally verified in the paper. The use of fly ash in adhesive materials for ceramic tiles is limited by unsatisfactory initial adhesiveness to sintered ceramic sherd as a result of a running pozzolanic reaction that lowers the efficiency of polymer additives. On the other hand, the use of adhesive and backfill coating materials for gluing ETICS board insulation materials has brought very good results.

Characterization of Mechanical Property Change in Polymer Aerogels Depending on the Ligand Structure of Acrylate Monomer

  • Lee, Kyu-Yeon;Jung, Hae-Noo-Ree;Mahadik, D.B.;Park, Hyung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.3
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    • pp.15-20
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    • 2016
  • In an effort to overcome the weakness of aerogel, polymer aerogels have been prepared by copolymerizing the different types of monomers through sol-gel process. Polymerizing the successive phase of a high internal phase emulsion, which has interconnected porous structure, porous polymer aerogel can be manufactured. In this paper, we use the styrene/divinylbenzene chain as a basic monomer structure, and additionally use 2-ethylhexyl methacrylate (2-EHMA) or 2-ethylhexyl acrylate (2-EHA) as monomers for distinguishing the visible mechanical properties of synthesized polymer aerogel. We can observe the different tendency of polymer aerogels by kinds of monomer or ratio. Flexibility and microstructure can be changed by the types of monomer. EHA polymer aerogel shows high flexibility and thin microstructure, and EHMA polymer aerogel shows high hardness and thick microstructure. EHA/EHMA polymer aerogel shows the intermediate nature between them. By utilizing the mechanical properties of three types of polymer aerogels to adequate situation or environment, polymer aerogels could be used as drug agent, ion exchange resin, oil filter and insulator, and so on.

Effect of gypsum content on the properties of PVC/Gypsum polymer blend material (PVC/Gypsum 복합체에서 Gypsum 의 영향)

  • N. V. Gian;Thai Hoan;Kim, M. Y.
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.221-224
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    • 2003
  • Polyvinyl chloride (PVC)/gypsum Polymer blend materials were prepared by melt blending of PVC with gypsum and additives. Effect of gypsum content on the properties of PVC/gypsum Polymer blend material was studied by investigating physico-mechanical properties, thermal properties and morphology development. It was found that the replacement of gypsum for methylene-butadiene-sarene (MBS) component in PVC/gypsum polymer blend material enhanced the tensile strength, but gradually decreased its impact strength. Besides, with the increase of gypsum content, the elongation at break of material gradually decreased. The Presence of the different gypsum contents made a shift of g1ass transition temperature and increased the thermal stability as well as the processing temperature range of polymer blends. The observation of morphology, the results of the physico-mechanical properties and thermal properties proved simultaneously that PVC/gypsum Polymer blend material with the gypsum content of 22.56 wt.% reached the optimum results among five kinds of PVC/gypsum Polymer blend materials investigated.

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Improved Efficiency of Polymer LEDs using Electron Transporting Layer

  • Kim, Jong-Lae;Kim, Jai-Kyeong;Cho, Hyun-Nam;Kim, Dong-Young;Hong, Sung-Il;Kim, Chung-Yup
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.125-126
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    • 2000
  • We report the use of fluorene based copolymers containing quinoline(POF66, PIF66) and pyridine(PFPV) units as electron transporting polymers for multi-layered LEDs. Double-layer device structure combining PIF66 as electron-transporting layer with the emissive MEHPPV showed a maximum quantum efficiency of 0.03%, which is 30 fold increased compared with ITO/MEHPPV/Al single-layer device. PFPV layer increased the quantum efficiency up to 0.1% in the device structure of ITO/(P-3:PVK)/PFPV/Al. The ETL with the electron deficient moiety improved the LED performance by the characteristics of electron transporting as well as hole blocking between emissive layer and metal cathode.

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Self-healing Engineering Materials: II. Inorganic Materials (자기치유 공학재료: II. 무기재료)

  • Kim, Min-Hee;Kang, Dong-Eun;Yoon, Ji-Hwan;Choi, Eun-Ji;Shim, Sang-Eun;Yun, Ju-Ho;Kim, Il
    • Clean Technology
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    • v.17 no.2
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    • pp.85-96
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    • 2011
  • Self-healing materials are a class of smart materials that have the structurally incorporated ability to repair damage caused by mechanical usage over time. A material (polymers, ceramics, metals, etc.) that can intrinsically correct damage caused by normal usage could lower production costs of a number of different industrial processes through longer part lifetime, reduction of inefficiency over time caused by degradation, as well as prevent costs incurred by material failure. The recent announcement from Nissan on the commercial release of scratch healing paints for use on car bodies has gained public interest on such a wonderful property of materials. This article is a second part of healing materials dealing with inorganic engineering materials such as metals, ceramics, and concrete. The healing mechanisms developed for the inorganic materials are to be discussed with the future prospect.