• Title/Summary/Keyword: WORK OF ADHESION

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Properties of Polymer-Modified Surface Preparation Mortars with Mineral Admixtures for Sewage Treatment Structures (하수처리구조물용 광물질 혼화재 병용 폴리머 혼입 바탕조정재의 특성)

  • Park, Seung-Min;Kim, Wan-Ki
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.30-31
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    • 2017
  • The objective of this study is to evaluate the performance of polymer-modified surface preparation mortars with pozzolanic materials for corrosion prevention method in deteriorated sewage treatment structures. The prepackaged-type surface preparation mortars are prepared with a polymer-binder ratio of 10%, ground granulated blast furnace slag contents of 0, 15, 30%, a fly ash content of 15%. And, the specimens are tested for workability, adhesion in tension, water absorption, crack and impact resistance. As a result, the prepackage-type surface preparation mortars for sewage treatment structure are satisfied with quality requirements by KS F 4716, Japan sewage work agency(JS) and JIS A 6916 for surface preparation mortars.

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Wear Characteristics of Atomic force Microscope Tip (Atomic Force Microscope Tip 의 마멸특성에 관한 연구)

  • 정구현;김대은
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.5
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    • pp.189-195
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    • 2003
  • Atomic Force Microscope (AFM) has been widely used in micro/nano-scale studies and applications for. the last few decade. In this work, wear characteristics of silicon-based AFM tip was investigated. AFM tip shape was observed using a high resolution SEM and the wear coefficient was approximately calculated based on Archard's wear equation. It was shown that the wear coefficient of silicon and silicon nitride were in the range of ${10}^{-1}$~${10}^{-3}$ and ${10}^{-3}$~${10}^{-4}$, respectively. Also, the effect of relative humidity and sliding distance on adhesion-induced tip wear was discussed. It was found that the tip wear has more severe for harder test materials. Finally, the probable wear mechanism was analyzed from the adhesive and abrasive interaction point of view.

Synthesis and Properties of CuNx Thin Film for Cu/Ceramics Bonding

  • Chwa, Sang-Ok;Kim, Keun-Soo;Kim, Kwang-Ho
    • The Korean Journal of Ceramics
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    • v.4 no.3
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    • pp.222-226
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    • 1998
  • $Cu_3N$ film deposited on silicon oxide substrate by r.f. reactive sputtering technique. Synthesis and properties of copper nitride film were investigated for its possible application to Cu metallization as adhesive interlayer between copper and $SiO_2. Cu_3N$ film was synthesized at the substrate temperature ranging from $100^{\circ}C$ to $200^{\circ}C$ and at nitrogen gas ratio above $X_{N2}=0.4. Cu_3N, CuN_x$, and FGM-structured $Cu/CuN_x$ films prepared in this work passed Scotch-tape test and showed improved adhesion property to silicon oxide substrate compared with Cu film. Electrical resistivity of copper nitride film had a dependency on its lattice constant and was ranged from 10-7 to 10-1 $\Omega$cm. Copper nitride film was, however, unstable when it was annealed at the temperature above $400^{\circ}C$.

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Fabrication and Cell Properties of Flattened Tube Segmented-in-Series Solid Oxide Fuel Cell-Stack Using Decalcomania Paper (전사지를 이용한 다전지식 평관형 고체산화물 연료전지 제작 및 셀 특성)

  • An, Yong-Tae;Ji, Mi-Jung;Park, Sun-Min;Shin, Sang-Ho;Hwang, Hae-Jin;Choi, Byung-Hyun
    • Korean Journal of Materials Research
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    • v.23 no.3
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    • pp.206-210
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    • 2013
  • In the segmented-in-series solid-oxide fuel cells (SIS-SOFCs), fabrication techniques which use decalcomania paper have many advantages, i.e., an increased active area of the electrode; better interfacial adhesion property between the anode, electrolyte and cathode; and improved layer thickness uniformity. In this work, a cell-stack was fabricated on porous ceramic flattened tube supports using decalcomania paper, which consists of an anode, electrolyte, and a cathode. The anode layer was $40{\mu}m$ thick, and was porous. The electrolyte layers exhibited a uniform thickness of about $20{\mu}m$ with a dense structure. Interfacial adhesion was improved due to the dense structure. The cathode layers was $30{\mu}m$ thick with porous structure, good adhesion to the electrolyte. The ohmic resistance levels at 800, 750 and $700^{\circ}C$ were measured, showing values of 1.49, 1.58 and $1.65{\Omega}{\cdot}cm^2$, respectively. The polarization resistances at 800, 750 and $700^{\circ}C$ were measured to be 1.63, 2.61 and $4.17cm^2$, respectively. These lower resistance values originated from the excellent interfacial adhesion between the anode, electrolyte and cathode. In a two-cell-stack SOFC, open-circuit voltages(OCVs) of 1.915, 1.942 and 1.957 V and maximum power densities(MPD) of 289.9, 276.1 and $220.4mW/cm^2$ were measured at 800, 750 and $700^{\circ}C$, respectively. The proposed fabrication technique using decalcomania paper was shown to be feasible for the easy fabrication of segmented-in-series flattened tube SOFCs.

A Study on the Performance of Mechanical Pressurizing Equipment(MPE) for Improving Bond Strength of Repair Materials for Concrete Box Structures (콘크리트 박스 구조물용 보수재의 부착강도 향상을 위한 기계식 가압장비(MPE) 성능에 관한 연구)

  • Yu, Hyeong-Sik;Jung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.1
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    • pp.477-483
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    • 2020
  • The rehabilitation methods used in existing concrete box structures rely on the method of attaching the repair material to the section of the structure with a spray equipment. In the case of ceiling or wall parts, the adhesion force to the repair material may be reduced by the gravity and dead load after construction. In subway structures, vibration causes a problem that reduces the initial adhesion. Supplementary measures are needed as the quality of repair varies depending on the worker's proficiency and construction environment. In this study, mechanical pressurization equipment was developed that can apply a certain pressure after construction of a repairwork to solve problems such as reduction of adhesion of repair materials by gravity and variation of repair quality by labor work. To find out the effect of the pressurized equipment, a chamber similar to the field conditions was constructed to measure the attachment strength different from the pressurized condition, the section, and the environmental conditions. The pressurization differed from the other parts, but the adhesion strength of up to 70% was increased.

Interfacial Evaluation of Surface Treated Jute Fiber/Polypropylene Composites Before and After Hydration Using Micromechanical Test (미세역학적 시험법을 이용한 표면처리된 Jute 섬유 강화 폴리프로필렌 복합재료의 수화 전·후 계면물성 평가)

  • Kim, Pyung-Gee;Jang, Jung-Hoon;Park, Joung-Man;Hwang, Byung-Sun
    • Journal of Adhesion and Interface
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    • v.8 no.3
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    • pp.9-15
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    • 2007
  • The interfacial evaluation of surface modified Jute fiber/polypropylene (PP) composites before and after hydration was investigated using micromechanical test and dynamic contact angle measurement. The IFSS of alkaline and silane-treated Jute fiber/PP composites increased, whereas after hydration, the IFSS of the untreated, alkaline- and silane-treated Jute fibers/PP composites decreased due to swelled fibrils by water infiltration. The interfacial adhesion of silane treated fiber/PP composites was higher than alkaline-treated or the untreated cases. The surface energies of Jute fiber treated under various conditions were obtained using dynamic contact angle measurement. Especially after hydration, the thermodynamic work of adhesion was calculated by considering water interlayer, which indicated the stability of IFSS between silane treated Jute fiber and PP matrix showing better than others.

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Measurements of the Adhesion Energy of CVD-grown Monolayer Graphene on Dielectric Substrates (단일층 CVD 그래핀과 유전체 사이의 접착에너지 측정)

  • Bong Hyun Seo;Yonas Tsegaye Megra;Ji Won Suk
    • Composites Research
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    • v.36 no.5
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    • pp.377-382
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    • 2023
  • To enhance the performance of graphene-based devices, it is of great importance to better understand the interfacial interaction of graphene with its underlying substrates. In this study, the adhesion energy of monolayer graphene placed on dielectric substrates was characterized using mode I fracture tests. Large-area monolayer graphene was synthesized on copper foil using chemical vapor deposition (CVD) with methane and hydrogen. The synthesized graphene was placed on target dielectric substrates using polymer-assisted wet transfer technique. The monolayer graphene placed on a substrate was mechanically delaminated from the dielectric substrate by mode I fracture tests using double cantilever beam configuration. The obtained force-displacement curves were analyzed to estimate the adhesion energies, showing 1.13 ± 0.12 J/m2 for silicon dioxide and 2.90 ± 0.08 J/m2 for silicon nitride. This work provides the quantitative measurement of the interfacial interactions of CVD-grown graphene with dielectric substrates.

Jet-Fuel-Resistant PVC Sealant Containing a Polyester Plasticizer (폴리에스터 가소제를 사용한 내제트유성 PVC계 실란트)

  • Nam, Byeong-Uk;Kim, Seog-Jun
    • Elastomers and Composites
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    • v.38 no.4
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    • pp.342-353
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    • 2003
  • This work is about the development of jet-fuel resistant PVC sealant using a polyester plasticizer. PVC copolymer was compounded with adipic acid glycol(Songcizer P-3000) or DOP plasticizers. Fuel-immersed and non-immersed penetration, solubility, flow, and elongation by tensile adhesion of PVC compounds were measured. Penetration increase by fuel immersion and solubility of PVC compounds with adipic acid glycol polyester plasticizer were smaller than those of PVC compounds with DOP plasticizer. Elongation by tensile adhesion test of PVC compound containing 500 phr of Songcizer P-3000 decreased proportionally to the content of DCDP (dicyclopentadiene) base petroleum resin adhesion promoter. Calcium carbonate($CaCO_3$) filler inhibited the diffusion of fuel in all the PVC compounds and decreased the solubility of PVC compounds containing Songcizer P-3000.

Improvement of the adhesion and resistivity of low-pressure chemical vapor deposited tungsten films by controlling deposition parameters (LPCVD로 증착한 텅스텐 박막의 증착 조건 제어에 의한 접착성 및 저항 특성 향상)

  • 노관종;윤선필;윤영수;노용한
    • Journal of the Korean Vacuum Society
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    • v.9 no.4
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    • pp.321-327
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    • 2000
  • Tungsten(W) thin films with good adhesion property and low resistivity (~10 $\mu$\Omega$$.cm) were deposited directly on $SiO_2$ by LPCVD. The adhesion property of W thin films on $SiO_2$ improves as the temperature and/or $SiH_4/WF_6$ gas ratio increase. Specifically tungsten thin films could be deposited on $SiO_2$ even at $350^{\circ}C$ if the gas ratio of 2 was employed. The resistivity of tungsten thin films deposited at $350^{\circ}C$ was high due to the presence of $\beta$-W. However, the resistivity can be minimized by increasing the amount of $H_2$ gas flow. Therefore, it is shown in this work that the adhesion of tungsten thin films on $SiO_2$ can be improved simply by controlling the process parameters (e.g., temperature, gas ratio and $H_2$ flow rate) without employing complex deposition methods or additional glue layers.

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Asphalt Sealant Containing the Waste Edible Oil (폐식용유를 이용한 아스팔트 실란트)

  • Kim, Seong-Jun
    • Elastomers and Composites
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    • v.39 no.1
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    • pp.61-70
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    • 2004
  • This work is about the development or asphalt sealant using the waste edible oil. Asphalt sealant has been used for crack filler and bridge deck joint sealer Several plasticizers such as aromatic or paraffin process oils, DOP, Bunker C fuel oil, and waste edible oil were compounded with the basic components such as asphalt(AP-5), a thermoplastic elastomer(SBS triblock copolymer), a tackifying agent(petroleum resin), and stabilizers. Penetration, softening point, ductility, and elongation by tensile adhesion of those asphalt sealant compounds were measured. Their properties were changed largely depending on both the type and content of plasticizers. Waste edible oil and DOP were the best plasticizers for the low temperature tensile adhesion characteristics. Penetration and elongation by tensile adhesion of asphalt sealant compounds increased with the increase of waste edible oil content and decreased with the increase of talc content. The manufacture of asphalt sealant with low penetration and excellent low temperature tensile adhesion was possible by the recipe optimization.