• Title/Summary/Keyword: Polymeric material

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The Study of Gas Sensor Using Rheological Properties of Polymeric Sensitive LB Films (고분자감응성 LB막의 유변학적인 특성을 이용한 가스센서 연구)

  • 강현욱;김정명;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.198-201
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    • 1997
  • The new system for identification of organic vapours and analysis method of mechanism between organic vapours and sensitive materials were attempted using the resonant resistance and resonant frequency of Quartz Crystal Analyzer (Q. C. A.). The resonant resistance shift means rheological changes in sensitive LB films occurred by the adsorption of organic vapours, while the resonant frequency shift represent the mass of organic vapour loaded in or on the sensitive LB films. It is thought that we can obtain more accurate response mechanism of organic vapour using the resonant frequency and resonant resistance diagram. The polymeric sensitive material were quantitively depositied using the LB method. In the experimental results, the adsorption behavior of organic vapour response can be decided by two type ; surface adsorption and penetration into sensitive material. Organic vapours had different positions in the Frequency-Resistance (F-R) diagram as to the kinds and concentrations of organic vapours. Thus F-R diagram can be applied to the development of one channel gas sensing system using the Quartz Crystal Analyzer.

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Micro Scale Mechanical property of Polymeric materials for FPD(Flat Panel display) (FPD에 사용되는 고분자 재료의 기계적 물성특성 연구)

  • Lee N.K.;Lee H.J.;Lee H.W.;Chong E.G.;Choi D.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.220-224
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    • 2005
  • The technology trend of Flat Panel Display (FPD) equipments have been demanded that there are compact and multi-function. Therefore, nano/micro scale patterned on polymeric materials of Back Light Unit (BLU) in Liquid Crystal Display (LCD) that has been investigated. This paper describes a series of Horizontal Type Micro Tensile Tester that were carried out to investigate the load strain distance performance of typical polymeric material sheets. The polymeric materials film that micro size shaped specimens for tensile test are used by Cold-Isostatic-Press (CIP). Test equipment is Horizontal type Micro Tensile Tester that is presented to measure the micro scale mechanical property of thin film for FPD. This paper presents which easy testing tools measure for micro patterned on polyethylene (PET) specimens.

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Effect of Ionizing Radiation on Mechanical and Electric Properties of Polymer Composites Based on Polyvinyl ether of Ethyleneglycol

  • Mun G. A.;Nurkeeva Z. S.;Kovtunets V. A.;Kupchishin A. I.;Akhmetkalieva G. T.;Khutoryanskiy V. V.;Al-Sayed A. A.;Soh Dea-Wha
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.3
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    • pp.25-28
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    • 2003
  • Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. New polymeric hydrogels based on vinyl ethers have been synthesized by the $\gamma$-initiated polymerization method. In this paper, we have studied the effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on polyvinylether of ethyleneglycol (PVEEG).

Stress Analysis in Polymeric Coating Layer Deposited on Rigid Substrate

  • Lee, Sang Soon
    • Corrosion Science and Technology
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    • v.14 no.4
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    • pp.161-165
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    • 2015
  • This paper presents an analysis of thermal stress induced along the interface between a polymeric coating layer and a steel substrate as a result of uniform temperature change. The epoxy layer is assumed to be a linear viscoelastic material and to be theromorheologically simple. The viscoelastic boundary element method is employed to investigate the behavior of interface stresses. The numerical results exhibit relaxation of interface stresses and large stress gradients, which are observed in the vicinity of the free surface. Since the exceedingly large stresses cannot be borne by the polymeric coating layer, local cracking or delamination can occur at the interface corner.

Effect of Dexamethasone Preincubation on Polymer-Mediated Gene Delivery

  • Choi, Joon-Sig;Lee, Min-Hyung
    • Bulletin of the Korean Chemical Society
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    • v.26 no.8
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    • pp.1209-1213
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    • 2005
  • Nuclear membrane is one of the main barriers in intracellular delivery of genetic materials. The previous report showed that glucocorticoid receptor dilated the nuclear pore to 60 nm in the presence of a ligand. It was also suggested that the transport of genetic material to nucleus might be facilitated by glucocorticoid. In this study, the effect of glucocorticoid preincubation in the polymeric gene delivery was investigated. The cells were preincubated with dexamethasone, a potent glucocorticoid, and transfection assays were performed with polyethylenimine (PEI) and polyamidoamine (PAMAM) dendrimer. As a result, the transfection efficiency of PEI or PAMAM to the cells in the presence of dexamethasone was enhanced, compared to the cells without dexamethasone. This effect was not observed in the cells preincubated with cholesterol. The polymer/DNA complex was stable in the presence of dexamethasone. In addition, the cytotoxicities of the polymeric carriers to the cells were observed in the presence of dexamethasone. In conclusion, dexamethasone enhances the transfection efficiency of polymeric carriers and may be useful in the development of polymeric gene carriers.

Study of Transport Phenomena of Large Ionic - Molecules Inside Polymeric Gel (고분자젤 내에서 분자체 거동현상 연구)

  • Park, Young-G.;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.18 no.1
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    • pp.1-6
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    • 2001
  • Theoretical model has been studied for the transport phenomena of molecules in the system where an electric potential is applied to the system in the axial direction. The effect of electrophoretic convection in the polymeric media is significantly contributed to separate large ionic-molecules because the conformation of large ionic-molecule quickly orients in the field direction. The dependence of the transport in the polymeric media upon field intensity and molecular size aids in understanding the transport of large ionic-molecule in the system, since the convective velocity of large ionic-molecule is accelerated inside a porous material. The transport distance of individual large ionic-molecule can be predicted using the reptation theories.

The Effect of the Surface Tension of Contaminants on Tracking Ageing of Polymeric Composites (오손액의 표면장력이 폴리머 복합재의 트래킹 열화에 미치는 영향)

  • 조한구;천종욱;이운용;한동희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.435-438
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    • 2002
  • In this paper, the effect of surface tension, wettability, flow rate of contaminants with varying surfactant content and frequency of applied voltage on the tracking breakdown of epoxy insulating materials were investigated. As the flow rate of contaminant is increased, the surface resistivity is decreased, and the leakage current is increased, the time to tracking breakdown is decreased. It is found that time to tracking breakdown depends on the surface tension of contaminant, that is difference of wettability And as the frequency of applied voltage is increased, time to tracking breakdown decreased.

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Effect of Annealing on Carbon Nitride Films Prepared by High Voltage Discharge Plasma (고전압 방전 플라즈마에 의해 합성한 질화탄소 박막의 열처리 효과)

  • 김종일
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.5
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    • pp.455-459
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    • 2002
  • I have investigated the effects of annealing on a polymeric $\alpha-C_3N_{4.2}$ at high pressure and temperature in the presence of seeds of crystalline carbon nitride films prepared by a high voltage discharge plasma. The samples were evaluated by x-ray photoelectron spectroscopy (XPS), infrared spectroscopy, Auger electron spectroscopy and x-ray diffraction(XRD). Notably, XPS studies of the film composition before and after annealing demonstrate that the nitrogen composition in $\alpha-C_3N_{4.2}$ material initially containing more than 58% nitrogen decreases during the annealing process and reaches a common, stable composition of ~43%. XPS analysis also shows that the nitrogen composition in the annealed films without polymeric $\alpha-C_3N_{4.2}$ was reduced from 35% to 17%. Furthermore the concentration of the sp$^3$bonded phase increased with the increment of the annealing temperature.