• Title, Summary, Keyword: Adhesion

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Curing Behavior and Adhesion Performance of Urea-Melamine-Formaldehyde (UMF) Resin by Staged Addition of Melamine (멜라민 첨가 순서에 따른 UMF 접착제의 경화거동과 접착력의 영향)

  • Xu, Guang-Zhu;Eom, Young-Geun;Lee, Young-Kyu;Lim, Dong-Hyuk;Lee, Byoung-Ho;Kim, Hyun-Joong
    • Journal of Adhesion and Interface
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    • v.10 no.2
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    • pp.84-89
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    • 2009
  • The objective of this research was to investigate the curing behavior and adhesion performance of urea-melamine-formaldehyde (UMF) resin for the four types of UMF-1, UMF-2, UMF-3, and UMF-4 which synthesized by the staged addition of melamine. Also, various network structures of these resin types were discussed based on their different curing behavior and adhesion performance. The curing behavior was evaluated by DMTA and thermal stability was checked by TGA. Adhesion performance was evaluated by dry and wet shear strengths and the pH value of each cured resin was checked to see its effect on the adhesion performance. The results indicated that the UMF-1 resin type by the addition of melamine initially with the urea and formaldehyde at the same F/(U+M) rate showed the lowest thermal stability, rigidity (${\Delta}E^{\prime}$), temperature of tan ${\delta}$ maximum ($T_{tan}\;_{\delta}$), and wet shear strength, and pH value of cured resin. In wet shear strength, however, the UMF-4 resin type appears to be slightly higher than UMF-1 resin type.

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Effect of Tea Polyphenols on the Adhesion of Highly Metastatic Human Lung Carcinoma Cell Lines to Endothelial Cells in Vitro

  • Zheng, Feng-Jin;Shi, Lin;Yang, Jun;Deng, Xiao-Hui;Wu, Yu-Quan;Yan, Xi-Qing;Huang, Ning
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.3751-3755
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    • 2012
  • Aim: Tea polyphenols are known to play roles in critical steps of human lung carcinoma cell metastasis. For understanding the mechanisms whereby they inhibit tumor metastasis, the present study was conducted to investigate their effects on the adhesion of highly metastatic lung carcinoma cell lines (PG cells) to endothelial cells (EC cells) and adhesion molecule expression in vitro. Methods: The expression of CD44 or CD54 in the PG cells was detected by flow cytometry and adhesion of PG cells to EC cells was assessed by confocal microscopy double fluorescence staining. Results: The results showed that tea polyphenols: (1) inhibited the expression of CD44 and CD54, two important adhesion molecules in the PG cells in a dose-dependent manner; (2) significantly blocked the adhesion of PG cells to EC cells not only in a state of rest but also when active; and (3) influenced CD44 and CD54 expression during the adhesion process of PG cells to EC cells. Conclusions: The data indicated that the blocking role of tea polyphenols in the adhesion of PG cells to EC cells is related to CD44 and CD54. The mechanism of tea polyphenol prevention of human lung carcinoma metastasis might be through inhibiting adhesion molecule expression to block cancer cell adhesion.

A Study on the Improvement of Adhesion in Tension and Flexure of Polymer Cement Mortar Depending on Various Test Methods (시험방법에 따른 폴리머 시멘트 모르타르의 인장 및 휨접착강도 개선에 관한 연구)

  • Jo, Young-Kug
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.1
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    • pp.47-57
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    • 2019
  • The purpose of this study is to evaluate the improvement effect of adhesion in tension and flexure of polymer cement mortars that have widely used as a repair-reinforcement material in construction field according to adding of polymer dispersions depending on different three types test methods. From the test results, the adhesion performance is improved with a raise in polymer-cement ratio irrespective of the type of polymer. The maximums of A type adhesion in tension, B type adhesion in tension and adhesion in flexure show 1.90 times, 2.17 times and 1.83 times, respectively that of plain cement mortar. The relative strength ratios, B type adhesion in tension and adhesion in flexure of polymer cement mortars to tensile and flexural strengths of plain mortar respectively are in ranges of 50.1% to 101.7% and 73.8% to 132.9% compared to 46.9% of plain mortar. It is apparent that polymer cement mortars with EVA and polymer cement ratios of 10% to 15% are recommended considering its adhesion performance and cost as a repair-reinforcement material in construction field.

Adhesion between Cu-18wt% Cr Alloy Film and Polyimide : Effect of Heat Treatment (Cu-18wt% Cr 합금박막과 폴리이미드사이의 접착력 : 열처리 영향)

  • 임준홍;김영호;한승희
    • Journal of the Korean institute of surface engineering
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    • v.26 no.6
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    • pp.327-333
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    • 1993
  • The effect of heat treatment on the adhesion between Cu-18wt% Cr film and polyimide has been studied by using T-peel test, AES, and XRD. Cu-18wt% Cr alloy and pure Cu films were sputter deposited onto pol-yimide. Cu was electroplated before and after heat treatment at $400^{\circ}C$ for 0.5 hr and 2 hrs respectively. The adhesion of metal film onto polyimide was considerably good before heat treatment, but heat treatment re-duced the peel adhesion strength in all specimens. The reduction in adhesion in adhesion strength values in the specimens which were plated after heat treatment was mainly due to Cr-O rich pahse formed in the metal/polyimide in-terface. In the specimens which were heat treated after plating, the enhanced ductility in the metal films con-tributes the peel adhesion strength by increasing the amount of deformation in metal strips.

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Changes in Adhesion Interface between Rubber and Steel Cord with Aging Treatment (열화처리에 따른 고무와 강선코드간 접착계면의 변화)

  • Seo, Gon;Sohn, Bongyoung
    • Applied Chemistry for Engineering
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    • v.5 no.4
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    • pp.630-636
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    • 1994
  • The changes in adhesion interface between rubber compound and brass plated steel cord after various aging treatments were studied by using an Auger electron spectrometer and a scanning electron microscope. After thermal aging, partial oxidation and additional growth of adhesion layer were observed. The adhesion layer and brass were partially removed after humid aging. With dynamic aging the adhesion layer was destroyed and the corrosion of steel core was proceeded. The changes in adhesion interface were discussed in terms of the adhesion properties determined from the stress-strain experiments.

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Influence of Parameters on Adhesion Strength on TiN Film by using R.F. Plasma Assisted Chemical Vapor Deposition (PACVD로 증착된 TiN 박막의 밀착성에 관하여)

  • Shin, Y.S.;Kim, M.I.
    • Journal of the Korean Society for Heat Treatment
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    • v.3 no.1
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    • pp.17-24
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    • 1990
  • In this study, TiN film was deposited onto steel by R.F.-PACVD in order to investigate the influence of parameters on the adhesion strength between film and substrate. Experimental results showed that adhesion strength by SAT is different from by optical microscopy. Adhesion strength is increased when the deposition temperature increases and is influenced by R.F. power and electrode distance. Especially heat treatment on the substrate has influenced over the adhesion strength, so it showed the 22 Newtons in adhesion strength by SAT and adhesion strength is decreased when deposition thickeness is thick and hardness is high. Also if the film is thick and high hardness simultaneous, the film was delaminated seriously.

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Re-adhesion Control for Wheeled Robot Using Fuzzy Logic (퍼지 제어기를 이용한 이동 로봇의 재점착 제어)

  • Kwon, Sun-Ku;Huh, Uk-Youl;Kim, Hak-Il
    • Proceedings of the KIEE Conference
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    • pp.2423-2425
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    • 2004
  • Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient(AFC) according to slip velocity. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the re-adhesion control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. fuzzy logic controller(FLC) is petty useful with slip through that compare fuzzy with PI control for the controller performance. These procedure is implemented using a Pioneer 2-DXE parameter.

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Anti-Slip Control for Wheeled Robot Based on Disturbance Observer (외란 관측기를 이용한 이동 로봇의 슬립 제어)

  • Kwon, Sun-Ku;Huh, Uk-Youl;Kim, Jin-Whan;Kim, Hak-Il
    • Proceedings of the KIEE Conference
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    • pp.50-52
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    • 2004
  • Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient according to slip velocity. In oder to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the anti-slip control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. These procedure is implemented using a Pioneer 2-DXE parameter.

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Development of Polymeric Layer for Enhancing The Adhesion of Nano-devices Fabricated by The Nanotransfer Molding Method

  • Lee, Gi-Seok;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.634-634
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    • 2013
  • Transfer molding methods have a problem that weak adhesion between nanostructures and substrates. It is important to make various nano scale applications, also the stability of nanostructure on substrate is related with device performance. We studied an effect of poly 4-vinylphenol (PVP) as the polymeric adhesion layer between organic nanowires and a Si substrate when the nanowires are transferred by liquid-bridge-mediated nanotransfer molding method (LB-nTM). Their structural stability was examined by optical microscopy, scanning electron microscopy as multiple transfer molding and washing process. Field-effect transistors were fabricated with organic semiconductor nanowires on a polymeric adhesion layer and their electrical properties showed no significant difference as the one without the adhesion layer. As a result, adhesion layer can be used in the washing process and making multi-layer nano-scale patterns.

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A Research on Suggestion of Proper Adhesion Strength about conjugation Method of outside Insulation. (외단열 고정 방법에 따른 적정 접착강도 제안에 관한 연구)

  • Park, Wan-Goo;An, Ki-Won;Park, Jin-Samg;Park, Ku-Byoung;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.93-94
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    • 2012
  • Recently outside insulation is applied on the building. Adhesion mortar and anchor are used fixing method of outside insulation. However, a research on proper Adhesion Strength is not performed. So outside insulation exfoliate from building in rainy with winds. Therefore, this research suggest proper adhesion strength about conjugation method of outside insulation. As a result, adhesion way using the adhesive mortar + anchor is best. And proper adhesion strength is over 1,065 N.

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