• Title/Summary/Keyword: polymer characteristics

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Adsorption and Release Characteristics of Sulindac on Chitosan-based Molecularly Imprinted Functional Polymer Films (키토산 기반 분자 각인 고분자 필름의 슐린닥 흡착 및 방출 특성)

  • Yoon, Yeon-Hum;Yoon, Soon-Do;Nah, Jae Woon;Shim, Wang Geun
    • Applied Chemistry for Engineering
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    • v.30 no.2
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    • pp.233-240
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    • 2019
  • Molecular recognition technology has attracted considerable attention for improving the selectivity of a specific molecule by imprinting it on a polymer matrix. In this study, adsorption and release characteristics of chitosan based drug delivery films imprinted with sulindac (SLD) were investigated in terms of the plasticizer, temperature and pH and the results were also interpreted by the related mathematical models. The adsorption characteristics of target molecules on SLD-imprinted polymer films were better explained by the Freundlich and Sips equation than that of the Langmuir equation. The binding site energy distribution function was also useful for understanding the adsorption relationship between target molecules and polymer films. The drug release of SLD-imprinted polymer films followed the Fickian diffusion mechanism, whereas the drug release using artificial skin followed the non-Fickian diffusion behavior.

The Aging Characteristics of Polymer Electrical Insulation Materials bv UV Radiation and Salt Water Spray (옥외용 고분자 전기절연재료의 염수 및 UV조사에 의한 열화 특성)

  • 최남호;한상일;한상옥;박강식;김종석;박양범
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.221-224
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    • 1997
  • In this study we investigated the acting characteristics of Polymers for electrical insulation by UV radiation and salt water spray treatment. We used the Polymers such as EPDM, SR. PTFE. EVA. We measured contact angle and surface resistance to know the aging characteristic of Polymer surface. And we use SEM to observe the change of the surface shape. Dry flashover voltage test impulse voltage test were carried for the polymer insulator(EVA) . Through this experiment and the analysis we could know the polymers have a good resistance to weathering conditions like as salt spray UV irradiation and mix of them. And we can compare the aging characteristics between Polymers. As a result, we could know that the surface characteristics of PTFE is better than the other. And the degree, electrical characteristics is affected by change of surface shape is not big.

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Electro-Optic Characteristics according to Distance between Pixel Electrodes in Fringe In-plane field Switching mode (화소 전극 간 거리가 Fringe In-plane field Switching mode의 전기 광학 특성에 미치는 영향)

  • Kim, Min-Su;Park, Ji-Woong;Jung, Jun-Ho;Ha, Kyung-Su;Lim, Young-Jin;Lee, Myong-Hoon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.337-338
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    • 2008
  • We have studied electro-optic characteristics of a high performance liquid crystal display using Fringe In-plane field Switching (FIS) mode. The strong electric fields cause more liquid crystals to reorient almost in plane above and between the pixel electrodes. As a result, the operation voltage is lower and transmittance is higher than those of Fringe Field Switching (FFS) and In-Plane Switching (IPS) modes. Apparently, the transmittance depends on voltage applied at the configurations of FIS mode which are proposed. Therefore, we have studied certain length of between electrodes for maximum transmittance and light intensity.

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Investigation of the residue formed on the silicon exposed to $C_4$F$_8$ helicon wave plasmas (고선택비 산화막 식각공정시 $C_4$F$_8$ 헬리콘 웨이브 플라즈마에 노출된 실리콘 표면의 잔류막 관찰)

  • 김현수;이원정;염근영
    • Journal of the Korean institute of surface engineering
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    • v.32 no.2
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    • pp.93-99
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    • 1999
  • Surface polymer layer formed on the silicon wafer during the oxide overetching using $C_4F_8$/ helicon wave plasmas and their characteristics were investigated using spectroscopic elipsometry, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry. Overetch percentage and dc-self bias voltage were varied to investigate the effects on the characteristics of the polymers remaining on the overetched silicon surface. The increase of bias voltage from -80 volts to -120 volts increased the C/F ratio and carbon bondings such as C-C, $C-CF_x$/, and C-Si in the polymer while reducing the thickness of the polymer layer. However, the increase of the overetch percentage from 50% to 100% did not change the composition of the polymer layer and the carbon bondings in the polymer layer remained same even though it increased the polymer thickness. The polymer layer formed at the higher dc-self bias voltage was more difficult to be removed by the following various post-etch treatments compared to that formed at the longer overetch percentage.

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Effect of Thermal Mechanical Stresses on Electrical Characteristics of Polymer Housed Surge Arresters (열-기계적 스트레스가 폴리머 피뢰기의 전기적 특성에 미치는 영향)

  • Cho, Han-Goo;You, Dae-Hoon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.6
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    • pp.555-560
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    • 2007
  • This paper describes the results of a study on the sealing integrity of polymer housed surge arrester based on the thermal mechanical test. The polymer housed surge arrester employs silicone insulating materials for its housing, instead of the conventional porcelain housing. The polymer housed surge arresters exhibited the highest sealing integrity because it is not air volume between the FRP(fiber reinforced plastics) module and the silicone housing. In accordance, the sealing integrity of station class surge arresters is investigated with moisture ingress test. And, the influence of sealing integrity was evaluated through such as measurement of the deflection, reference voltage, leakage current. In electrical characteristics, reference voltage decreased in the range of $16.45{\sim}16.15\;kV$ with after thermal mechanical test. In contrary, despite the continued moisture ingress, the polymer housed surge arresters exhibited almost the same leakage current value and the resistive leakage current has risen slightly. As a results, It was thought that the polymer housed surge arresters shows good stability with sealing integrity.

Characterization of Specific Interactions in Organoclay Nanocomposites

  • Lim, Sang-Kyun;Lee, Eun-Hee;Chin, In-Joo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.292-292
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    • 2006
  • A two-step process of the solution blending and the subsequent melt mixing in a Brabender mixer was used to prepare clay nanocomposites of SAN/PVC and of ABS, respectively. It was found that the new method was effective in obtaining well-dispersed nanocomposites for both cases. The glass transition behavior of the organoclay nanocomposites were analyzed by using theoretical equations. The interaction characteristics were evaluated by using the solubility parameters estimated from the group molar attraction constants.

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