• 제목/요약/키워드: wetting properties

검색결과 268건 처리시간 0.027초

Molecular Imprints in Nanostructured Polymer Surfaces - A New Generation of Biomimetic Materials for Chemical Sensors

  • Haupt, Karsten
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.31-32
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    • 2006
  • We describe the preparation of nanostructured molecularly-imprinted surfaces using nanomolding on porous alumina. In molecular imprinting functional and cross-linking monomers are copolymerized in the presence of a molecular template, resulting in synthetic receptor materials. The drug propranolol and the dye fluorescein were used as the molecular imprinting templates. Binding studies with imprinted and non-imprinted surfaces revealed specific recognition of the templates and thus the existence of selective binding sites. In addition, the surface properties of the films were studied by water contact angle measurements. It was found that, depending on the monomers used, certain nanostructures induced great changes in the wetting properties of the surface.

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Direct Formation of Bi-level Microstructures for Wide-viewing Liquid Crystal Displays with Plastic Substrates

  • Hong, Jong-Ho;Cho, Seong-Min;Kim, Yeun-Tae;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1286-1289
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    • 2008
  • We report on a wide-viewing liquid crystal (LC) display with bi-level microstructures spontaneously formed by selective wetting on a chemically heterogeneous surface. The bi-level microstructures serve as spacers for maintaining uniform cell gap, as well as protrusions for wide-viewing properties. Our LC cell having the bi-level microstructures shows good electro-optic properties.

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Squeeze Casting법에 의해 제조된 A356/coated SiC복합재료의 미세조직과 기계적 특성에 관한 연구 (A Study on Microstructures and Mechanical Properties of A356/coated SiC Composites Fabricated by Squeeze Casting)

  • 이경구;이도재
    • 한국주조공학회지
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    • 제14권5호
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    • pp.429-437
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    • 1994
  • Influence of interfacial structure between matrix and particle in A356/coated SiC composite fabricated by squeeze casting method was studied. Experimental variables are types of coated metallic film on SiC particles such as Cu, Ni-P, and applied pressure for squeeze casting. It was found that coating treatment on SiC particles improves the wetting of liquid A356 alloy on SiC particles. SiC particle distribution is very homogeneous in A356 matrix alloy which is fabricated by squeeze casting. Analysing the surface morphology of fractured A356/coated SiC, it was concluded that metallic thin film by coating treatment on SiC particle improves the interfacial bonding between particle and matrix, and so does on mechanical properties such as tensile strength. However, there was on significant difference in hardness between those composite made of as-received SiC particle and coated SiC particle.

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Preparation and Properties of Polyolefin Graft Polymer available as a Primer for Polyurethane Adhesive (I) Synthesis of polyolefins with cyclic acid anhydride by free radical graft polymerization

  • Ryu, Ki Jung;Kim, Min Jung;Min, Seong Kee;Lee, Won Kee;Park, Chan Young
    • Elastomers and Composites
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    • 제50권2호
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    • pp.119-125
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    • 2015
  • Because of their low surface free energy and absence of polar groups at the surface, polyolefins are substrates whose wetting and adhesion are very difficult. Free radical grafting of monomers to backbone polymer is one of the most attractive ways for the chemical modification of polymers. Synthesis of graft copolymer through graft polymerizations of PE and/or PP with phthalic anhydride (PhAn) was made and FTIR spectra of the graft polymer were the examined. And also the effects of phthalic anhydride content on the grafting ratio, thermal properties and contact angle of the graft polymer were examined.

Influence of water saturation on fracture toughness in woven natural fiber reinforced composites

  • Kim, Hyo-Jin;Seo, Do-Won
    • Advanced Composite Materials
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    • 제16권2호
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    • pp.83-94
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    • 2007
  • Woven sisal textile fiber reinforced composites were used to evaluate fracture toughness, tensile and three-point bending. The water absorption testing of all specimens was repeated five times in this study. All specimens were immersed in pure water during 9 days at room temperature, and dried in 1 day at $50^{\circ}C$. Two kinds of polymer matrices such as epoxy and vinyl-ester were used. Fractured surfaces were taken to study the failure mechanism and fiber/matrix interfacial adhesion. It is shown that it can be enhanced to improve their mechanical performance to reveal the relationship between fracture toughness and water absorption fatigue according to different polymer matrices. Water uptake of the epoxy composites was found to increase with cycle times. Mechanical properties are dramatically affected by the water absorption cycles. Water-absorbed samples showed poor mechanical properties, such as lower values of maximum strength and extreme elongation. The $K_{IC}$ values demonstrated a decrease in inclination with increasing cyclic times of wetting and drying for the epoxy and vinyl-ester.

인공경량골재 사용 경량투수블록의 제조시간 변화에 따른 배합 및 압축강도 특성 (A Compressive Strength and Mixing Properties of Lightweight Porous Block Using Lightweight Aggregate by Variation of Manufacture Time)

  • 김영욱;이경수;오태규;정수빈;반준모;최세진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
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    • pp.118-119
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    • 2018
  • The purpose of this study is to investigate the compressive strength and mixing properties of the lightweight block, which has been manufactured without the pre-wetting process, in the lightweight block using domestic artificial lightweight aggregate. The test results of the specimens produced within 30 minutes after the preparation showed high compressive strength but poor permeability. Therefore, the elapsed time after the manufacture, which is expected to have required compressive strength and permeability, was about 60 minutes in this study.

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Preparation and Characterization of Ophthalmic Hydrophilic Silicone Lens Containing Zinc Oxide and Iron Oxide Nanoparticles

  • Shin, Su-Mi;Sung, A-Young
    • 한국재료학회지
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    • 제31권8호
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    • pp.427-432
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    • 2021
  • This study uses silicone monomer, DMA, crosslinking agent EGDMA, and initiator AIBN as a basic combination to prepare hydrogel lenses using fluorine-based perfluoro polyether and iron oxide and zinc oxide nanoparticles as additives. After manufacturing the lens using iron oxide nanoparticles and zinc oxide nanoparticles, the optical, physical properties, and polymerization stability are evaluated to investigate the possibility of application as a functional hydrogel lens material. As a result of this experiment, it is found that the addition of the wetting material containing fluorine changes the surface energy of the produced hydrogel lens, thereby improving the wettability. Also, the addition of iron oxide and zinc oxide nanoparticles satisfies the basic hydrogel ophthalmic lens properties and slightly increases the UV blocking performance; it also increases the tensile strength by improving the durability of the hydrogel lens. The polymerization stability of the nanoparticles evaluated through the eluate test is found to be excellent. Therefore, it is judged that these materials can be used in various conditions as high functional hydrogel lens material.

고로슬래그미분말 혼입율에 따른 회수수 사용 경량모르타르의 유동성 및 강도특성 (The Fluidity and Comprssive Strength Properties of Lightweight Mortar Using Recycling Water according to Blast Furnace Slag Powder Ratio)

  • 배성호;이재인;김지환;오태규;최세진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.136-137
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    • 2020
  • This study compared and analyzed the fluidity and strength characteristics of mortar using the recycling water, indicates strong alkali properties, as pre-wetting water of artificial light aggregate to increase usage ratio of recycling.

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사이잘 섬유 강화 복합재료의 기계적 특성에 미치는 표면처리와 흡습의 영향 (Effects of Water Absorption and Surface Treatment on Mechanical Properties of Sisal Textile Reinforced Composites)

  • 김효진;서도원;박한주;전양배;임재규
    • 대한기계학회논문집A
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    • 제30권7호
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    • pp.779-786
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    • 2006
  • Woven sisal textile reinforced composites were manufactured to evaluate fracture toughness, and tensile test. All specimens were immersed in water five times. All specimens are immersed in pure water during 9 days at room temperature, and dried in 1 day at $50^{\circ}C$. Two kinds of polymer matrices such as epoxy and vinyl-ester were used. Fractured surface were investigated to study the failure mechanism and fiber/matrix interfacial adhesion. It is shows that it can be enhanced to improve their mechanical performance to reveal the relationship between fracture toughness and water absorption fatigue according to different polymer matrices. Water uptake of the epoxy composites was found to increase with cycle times. Mechanical properties are dramatically affected by the water absorption cycles. Water-absorbed samples observed poor mechanical properties such as lower values of maximum strength and extreme elongation. The $K_{IC}$ values demonstrate a decrease in inclination with increasing cyclic times of wetting and drying fur the epoxy and vinyl-ester.

Petroleum Sulfonate의 합성에 있어서 황산화율이 계면활성 특성 및 시멘트 몰타르의 유동성에 미치는 영향 (Effects of Sulfonation Ratio in Petroleum Sulfonate Synthesis on Interfacial Properties and on Fluidity Properties of Cement Mortar)

  • 김영호
    • Korean Chemical Engineering Research
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    • 제48권4호
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    • pp.444-449
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    • 2010
  • 본 연구에서는 정유회사 등에서 폐기되는 부생유(pyolyzed fuel oil)를 황산화 반응하여 petroleum sulfonate(PS)를 합성하였다. 합성된 PS는 계면활성 성질을 나타내었으며 이는 황산화율과 관계가 있었다. 또한 반응에 있어서 황산화율은 온도 및 시간에 따라 속도에 차이는 있었으나 대부분의 경우 40~50% 정도에서 황산화율이 거의 포화에 이르렀다. 황산화율이 증가함에 따라서 친수성이 증가하여 용액의 표면장력이 낮아졌으나 과도한 황산화율에서는 친수성이 너무 강하여 표면장력 값이 오히려 증가하였다. 황산화율에 따라서 적정한 친수-친유 비율에서는 낮은 표면장력과 시멘트에 대하여 우수한 젖음성을 나타내었다. 황산화율에 따라서 PS는 시멘트 표면에 대한 흡착량에 차이를 보였으며 흡착량이 클수록 시멘트에 대한 젖음성이 증가하여 시멘트 입자의 제타전위를 높였으며 보다 우수한 시멘트 몰타르 유동성을 나타내었다.