• 제목/요약/키워드: Repellency

검색결과 180건 처리시간 0.049초

Water Repellency on a Nanostructured Superhydrophobic Carbon Fibers Network

  • Ko, Tae-Jun;Her, Eun-Kyu;Shin, Bong-Su;Kim, Ho-Young;Lee, Kwang-Ryeol;Hong, Bo-Ki;Kim, Sae-Hoon;Oh, Kyu-Hwan;Moon, Myoung-Woon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.224-224
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    • 2012
  • For decades, carbon fiber has expanded their application fields from reinforced composites to energy storage and transfer technologies such as electrodes for super-capacitors and lithium ion batteries and gas diffusion layers for proton exchange membrane fuel cell. Especially in fuel cell, water repellency of gas diffusion layer has become very important property for preventing flooding which is induced by condensed water could damage the fuel cell performance. In this work, we fabricated superhydrophobic network of carbon fiber with high aspect ratio hair-like nanostructure by preferential oxygen plasma etching. Superhydrophobic carbon fiber surfaces were achieved by hydrophobic material coating with a siloxane-based hydrocarbon film, which increased the water contact angle from $147^{\circ}$ to $163^{\circ}$ and decreased the contact angle hysteresis from $71^{\circ}$ to below $5^{\circ}$, sufficient to cause droplet roll-off from the surface in millimeter scale water droplet deposition test. Also, we have explored that the condensation behavior (nucleation and growth) of water droplet on the superhydrophobic carbon fiber were significantly retarded due to the high-aspect-ratio nanostructures under super-saturated vapor conditions. It is implied that superhydrophobic carbon fiber can provide a passage for vapor or gas flow in wet environments such as a gas diffusion layer requiring the effective water removal in the operation of proton exchange membrane fuel cell. Moreover, such nanostructuring of carbon-based materials can be extended to carbon fiber, carbon black or carbon films for applications as a cathode in lithium batteries or carbon fiber composites.

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고밀도 직물의 반복세탁 및 세탁조건에 따른 투습.발수성 변화 (Changes in Moisture Permeability and Waterproofness of High-density Fabric by Repeated Laundering and Condition)

  • 노의경;한정은;김은애
    • 한국의류학회지
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    • 제34권11호
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    • pp.1798-1811
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    • 2010
  • This research evaluates the changes in the comfort-related properties of high-density fabric, such as moisture permeability and waterproofness, in order to assess the relative importance of laundry conditions for clothing properties after repeated laundering and suggest the best laundering conditions for high-density fabric through the identification of the most influential factor. A commercial high-density fabric was washed 25 times in a drum-type washer using nine different laundry conditions based on profiles derived from a fractional factorial design. To evaluate the changes in the comfort-related properties of the fabric, pore size, air permeability, water vapor transport, water repellency, and water resistance were measured. The comfort-related properties of the fabric deteriorated after repeated laundering by the damaged surface finish; in addition, the damaged surface also changed the pore size. As a result, the water repellency and water resistance decreased. The detergent was the most responsible factor to change the properties among the four factors of detergent, hardness, temperature, and RPM. The best laundering conditions for the fabric was a neutral detergent, soft water of 70ppm, a temperature of $15^{\circ}C$, and 30rpm.

농산물 저온유통용 내수 골판지 상자의 제조(제2보) - 골판지의 내수 및 내습성 향상을 위한 약품 적용 방법 - (Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(II) - Application Methods of Chemicals for Improving Water and Moisture Resistance of Corrugated Boards -)

  • 조중연;민춘기;신준섭
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2004년도 춘계학술발표논문집
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    • pp.192-210
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    • 2004
  • Application methods of chemicals were investigated tn minimize strength reduction of corrugated boards under the high humidity environment encountered in the cold chain system. Starch insolubilizers were introduced in the starch solution preparation of the Stain hall method and their insolubilization effect of starch binder were estimated. The performance of water repellent agents(WRA) and moisture proof agents(MPA) were evaluated in terms of water and moisture resistance. And effects of the combination of the chemicals and the coating method were also examined. Addition of the polyamine polyamide insolubilizer to the main part in the Stain hall process improved the binding force and water resistance of starch, which contributed to minimize the strength reduction of paper under the high humidity environment. AZC and Glyoxal type insolubilizers could not be used in the experiment due to an excessively increased viscosity of starch solution and the poor stability. Conventional WRA treatment to the base paper enhanced water and moisture resistance very slightly even though water repellency of the paper reached R10 by the treatment. MPA showed excellent performance than WRA not only in water and moisture resistance but in water repellency. Double coating on paper with MPA was more effective than the single coating at the same coating weight. A newly developed MPA showed excellent performance and runnability only by a single coating instead of a double coating.

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견직물의 수지가공에 관한 연구 (A Study on the Resin Finishing of Silk Fabric -Silicone Resin Finishing-)

  • 남중희;탁태문
    • 한국잠사곤충학회지
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    • 제27권2호
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    • pp.28-39
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    • 1985
  • 견직물의 실용성능(방추도, 세탁성)을 개선할 목적으로 실크하브다이(silk habutae)에 실리콘수지를 유화 가공법으로 처리하였다. 실리콘가공 하브다이의 방추도, 발수도, 유연도, 강신도, 수분율 등은 직물검사 방법에 따라서 검사하였고 가공 후 견피브로인의 구조적인 변화를 구명하기 위하여 주사전자현미경, 아미노산분석, X-선 회절강도, FT-IR 흡수분석에 의하여 검토한 결과 아래와 같은 결과를 얻었다. 1) 견하브다이 직물의 방추도는 soaping 처리오 큐어링 조건에 의하여 현저히 개선되었다. 2) 실리콘 수지 가공에 의하여 견하브다이의 발수도와 유연도가 향상되었고, 가공 후 silk fibroin을 주사전자현미경으로 관찰한 결과 견섬유 특유의 불규칙한 섬유표면은 평활하게 관찰되었다. 3) 실리콘 수지와 silk fibroin의 반응에 따라서 피브로인 조성 아미노산 중 극성기를 가지고 있는 아미노산의 감소비율이 현저하였다. 4) 실리콘 수지가공 silk habutae는 soaping에 의하여 X-선 회절강도가 높아지는 경향이었다. 5) 가공 후 견하브다이의 FT-IR 흡수곡선에 실록산등의 peak가 검출된 것으로 미루어 fibroin의 개질이 가능하다고 생각된다.

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농산물 저온유통용 내수골판지 상자의 제조(제4보) - 대상농산물별 저온유통조건, 유통경로 및 포장규격 조사 분석 - (Manufacture of Water-Resistant Corrugated Fiberboard Boxes for Agricultural Products in the Cold Chain System (IV) - Measurement and analysis of storage condition, distribution route, and packaging method for selected agricultural products -)

  • 이명훈;조중연;민춘기;신준섭
    • 펄프종이기술
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    • 제38권1호통권113호
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    • pp.62-69
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    • 2006
  • This study was carried out to measure and analyze the storage condition, distribution route, and packaging method of four selected agricultural products(small tomato, cabbage, peach, and carrot) in the cold chain system. It was shown that dew-forming phenomenon by fruits and vegetables deteriorates the agricultural product quality and physical properties of corrugated fiberboard box during the cold chain system. The compressive strength deterioration in corrugated fiberboard boxes was much greater for single wall(SW) corrugated fiberboard containers than for double wall(DW) in low temperature-high humidity condition. To reduce the deterioration of box and dew-forming phenomenon, water-repellency treatment should be over $R_6$. However, water-resistant treatment of corrugated fiberboard containers would be effective under high relative humidity conditions more than 75% RH. It was suggested that functional corrugated fiberboard box packaging would be an optimum method to reduce the deterioration of agricultural products quality by. It was also achieved controlling the relative humidity and temperature during the storage and physical distribution process.

과불화 알코올을 이용한 발수성 폴리우레탄 코팅 필름의 제조 (Preparation of Water Repellent Polyurethane Coating Films Using Perfluoroalkyl Alcohol)

  • 김남우;안치용;송기창
    • Korean Chemical Engineering Research
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    • 제54권3호
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    • pp.387-393
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    • 2016
  • 불소가 함유된 폴리우레탄 코팅 용액을 과불화 알코올, toluene diisocyanate와 polycarbonate diol을 출발물질로 사용하여 합성하였다. 이렇게 합성된 불소 함유 폴리우레탄 코팅 용액을 기재인 PC 위에 스핀 코팅 후 $120^{\circ}C$에서 열경화시켜 코팅 필름을 제조하였다. 제조된 코팅 필름의 물성을 FT-IR spectroscopy, UV-visible spectrometer, 접촉각 측정기와 연필경도 측정기를 사용하여 분석하였다. 과불화 알코올의 첨가는 코팅 필름의 발수성을 향상시켜, 물 접촉각을 $81^{\circ}C$에서 $111^{\circ}C$로 증가시켰다. 그러나 코팅 필름의 연필경도는 과불화 알코올의 첨가에도 불구하고 H로 일정하였다.

흙페인트의 적절한 사용을 위한 표면경도 및 발수성에 관한 연구 (Surface Hardness and Water Repellet of Earth Paint)

  • 황혜주;노태학;이진실
    • KIEAE Journal
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    • 제16권3호
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    • pp.83-88
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    • 2016
  • Purpose : This study aimed to verify the surface hardness and water repellency of earth paint manufactured with earth, a natural material, and provide the results as basic data for paint made with natural materials. Method : After presenting the accurate manufacturing methods for basic materials for paint, the authors conducted and analyzed experiments to evaluate surface hardness and water repellency, fundamental performance indicators for paint, based on different mixture ratios. From the results of the experiment to assess the surface hardness of flour-based earth paint, we observed high surface hardness only after painting the specimen three times. Since potato starch-based earth paint has higher viscosity than its flour-based counterpart, the former did not paint well on the first occasion, resulting in low surface hardness. After painting two or more times, however, it was observed to have higher surface hardness than flour-based earth paint. Result : It was found that at least three iterations of painting was required to obtain high surface hardness of potato starch-based earth paint. Furthermore, the results of the water resistance experiment of earth paint suggest that the use of environment-friendly finishing materials coupled with boiled linseed oil will mitigate the drawbacks of earth paint. The experiment with one-year-old specimens also demonstrated similar water repellent characteristics, which indicates that the performance will improve once the paint has dried for a sufficient period of time.

식물정유 및 혼합물의 점박이응애(Tetranychus urticae Koch)에 대한 살비 및 기피활성 (Toxicity and Repellent Activity of Plant Essential Oils and Their Blending Effects Against Two Spotted Spider Mites, Tetranychus urticae Koch)

  • 윤준호;탁준형
    • 한국응용곤충학회지
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    • 제57권3호
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    • pp.199-207
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    • 2018
  • 본 연구에서는, 20종의 식물정유를 이용하여 점박이응애 성충에 대한 살비활성 및 기피활성을 확인하였다. 살비활성 평가에서는 샌달우드 오일이, 기피활성 평가에서는 클라리 세이지 오일이 가장 높은 효과를 나타내었고, 평가에 사용한 20종의 식물정유간에는 살비활성과 기피활성간의 상관관계가 매우 낮게 나타났다. 높은 활성을 나타낸 정유들의 혼합시험에서는, 거의 대부분의 조합이 서로간에 저해효과를 갖는 것으로 확인되었다. 샌달우드 및 클라리 세이지 오일의 구성성분은 GC/MS 분석을 통해 확인하였으며, 샌달우드는 세스퀴터펜류가, 클라리 세이지 오일은 모노터펜류가 주종을 이루었다. 클라리세이지 오일의 구성성분 중에서는 linalyl acetate가 가장 높은 함량을 갖고 있을 뿐만 아니라, 해당정유가 기피효과를 갖는 주된 효능물질임을 확인하였다.