• 제목/요약/키워드: Polymeric materials

검색결과 843건 처리시간 0.042초

생체의료용 기능성 고분자 재료의 개발 (Functional Polymeric Materials for Biomedical Application)

  • 성용길;송대경;성정석
    • 폴리머
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    • 제30권1호
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    • pp.1-9
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    • 2006
  • 생체의료용 기능성 고분자재료의 개발에 관한 연구를 고분자의 기능성, 생체적합성 및 생분해성을 토대로 다루었다. 본 연구실에서 합성한 기능성 생분해 고분자들을 비롯하여 생분해성 고분자 생체재료, 온도 감응성 고분자재료, 양이온성 고분자재료, 비축합성 고분자 생체재료, 조직공학을 위한 생체고분자 DNA 매트릭스 및 RNAi 기법을 위한 고분자 등의 기능성 고분자 생체재료에 관련된 연구들을 정리하고, 가까운 장래에 의료용으로 이용될 수 있는 기능성 생체고분자에 대한 연구들을 제안하였다.

공기 분리용 열분해 탄소막 (Pyrolytic Carbon Membranes for Air Separations)

  • Singh, Anshu;Koros, W.J.
    • 멤브레인
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    • 제7권1호
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    • pp.15-21
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    • 1997
  • Carbon molecular sieve (CMS) membranes were synthesized by the pyrolysis of polymeric precursors. The CMS materials had oxygen-nitrogen selectivities much higher than those observed for the polymeric precursors. Typically molecular sieving materials have diffusion selectivities much higher than polymeric materials. This has been identified as a result of higher entropic selectivity of the molecular sieving materials. A study of the development of molecular sieving properties as the polymeric precursor is pyrolyzed into a CMS material will offer us an insight into polymeric molecular structures needed for enhanced entropic selectivity membrane materials.

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Influence of Reaction Conditions on the Grafting Pattern of 3-Glycidoxypropyl trimethoxysilane on Montmorillonite

  • He, Wentao;Yao, Yong;He, Min;Kai, Zhang;Long, Lijuan;Zhang, Minmin;Qin, Shuhao;Yu, Jie
    • Bulletin of the Korean Chemical Society
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    • 제34권1호
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    • pp.112-116
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    • 2013
  • Surface modification of montmorillonite (MMT) with 3-glycidoxypropyl trimethoxysilane (3GTO) in mild methanol/water mixture has been investigated in detail. The influence of reaction conditions (including silane concentration in feed, reaction time and reaction temperature) on the grafting amount and yield of silane, and further on the grafting pattern of silanes was studied by thermogravimetric analysis, elemental analysis, X-ray diffraction (XRD) and BET. Higher silane concentration, longer reaction time and higher reaction temperature are all benefit to higher grafting amount. When the grafting reaction was performed with 3 mmol/g silane concentration, at $90^{\circ}C$ for 24 h, the grafted amount and yield of silane reached 1.4443 mmol/g and 30%, respectively. Based on the XRD and BET data analysis, a speculation that the grafting pattern of silanes was concentration dependence was proposed.

Surface Modification of Colloidal Silica Nanoparticles: Controlling the size and Grafting Process

  • He, Wentao;Wu, Danhua;Li, Juan;Zhang, Kai;Xiang, Yushu;Long, Lijuan;Qin, Shuhao;Yu, Jie;Zhang, Qin
    • Bulletin of the Korean Chemical Society
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    • 제34권9호
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    • pp.2747-2752
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    • 2013
  • Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of $T_2$ and $T_3$ except for $Q_2$ and $Q_3$ signals by CP/MAS $^{29}Si$ NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.

Liquid crystal display utilizing bent-core liquid crystals: advantages and problems

  • Takezoe, Hideo;Gomola, Kinga;Guo, Lingfeng;Dhara, Surajit;Shimbo, Yoshio;Gorecka, Ewa;Pociecha, Damian;Mieczkowski, Jozef
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.8-9
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    • 2009
  • After reviewing the principle of a new display utilizing bent-core liquid crystals, we summarize the advantages and problems of this display. Then we will introduce our effort to overcome these problems mostly by synthesizing new materials. We obtained a variety of newly synthesized compounds showing the $SmAP_R$ phase. Mixing was effective to decrease and widening the temperature range of the $SmAP_R$ phase.

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Polymeric and Oligomeric OTFT Materials Containing Fused Aromatics

  • Kim, Hyeong-Sun;Kim, Yun-Hi;Jung, Sung-Wook;Yi, Mi-Hye;Pyo, Seung-Moon;No, Yong-Young;Kim, Dong-Yu;Kwon, Soon-Ki
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.161-161
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    • 2006
  • New polymeric and oligomeric OTFT materials containing fused aromatics such as anthracene and naphthalene have been designed, synthesized and characterized. The new OTFT materials were prepared by palladium-catalyzed Suzuki cross-coupling reaction. The obtained materials were characterized by various spectroscopic methods such as UV-vis, PL, cyclovoltametry, and XRD. The obtained OTFT materials containing fused aromatics showed high thermal stability above $350^{\circ}C$ In OTFT devices using new materials, high charge carrier mobility and on/off ratio were observed.

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Observation of Carbon Nanotube/Elastomer Composites by Atomic Force Microscopy

  • Niikura, Ayako;Nakajima, Ken;Fujinami, So;Ono, Michio;Nishi, Toshio
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.288-288
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    • 2006
  • Natural rubbers (NR) reinforced by multi-wall carbon nanotubes (MWCNT) was found to show extraordinary improvement of mechanical property. We speculated that this was owing to the interfacial phase that surrounded CNT and investigated about the phase by atomic force microscopy (AFM). Using force modulation mode and force-distance curve analyses, we succeeded in obtaining the information of its nanometer-scale rheological property. We found that was actually surrounded by the interfacial phase, that had softer modulus than NR matrix.

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Liquid Crystal Alignment on Treated Surfaces

  • Chung, Doo-Han;Shioda, Tatsutoshi;Okada, Yoshinori;Park, Byoung-Choo;Takezoe, Hideo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.1088-1091
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    • 2003
  • We have studied liquid crystal orientation on rubbed and photoaligned polymer surfaces. The following topics will be presented; (1) visualization of nonuniformity of rubbing, (2) competition between grooves and photoalignment and (3) alignment process of 5CB evaporated on treated surfaces. Through these topics, the importance of the intermolecular liquid crystalline interaction will be emphasized.

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