• Title/Summary/Keyword: Anti-adhesion property

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A Study on the Aging Behavior of Ship Organic Coating by the Flow Induced Shear Stress (유동 전단응력에 의한 선박 유기도막의 열화거동 연구)

  • Park Hyun;Park Jin-Hwan;Ha Hyo-Min;Chun H.H.;Lee In-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.9-14
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    • 2006
  • Analysis has been made of the anti-corrosive property of organic coating under the shear stress of the flow by means of AC impedance method. Marine anti-corrosive painted panels were placed in the water channel with varying flow rate, thereby experiencing varying flow shear stress on the surfaces. The velocities of the salt water were ranged from 1.48 to 5.2 m/s and the coating thickness of from $70{\mu}m\;to\;140{\mu}m$. For all coating thicknesses investigated, the poorer anti-corrosive property and the lower adhesion strength have been found for the higher shear stress. It has been found that the shear stress accelerates the aging of organic marine coatings.

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Characteristics Evaluation of Thin Films Formed on Mg-Al Alloy in Various Chemical Conversion Solution Conditions (다양한 화성처리 용액 조건에서 마그네슘-알루미늄 합금위에 형성된 박막의 특성 평가)

  • Jang Seok-Ki;Kim Seong-Jong;Kim Jeong-Il
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.1
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    • pp.98-106
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    • 2005
  • The chemical conversion film formed on magnesium alloy was investigated by using the colloidal silica with some parameters such as solution pH. temperature, solution conditions, and treatment time. Moreover. the solutions consisted of colloidal silica titanium sulfate, and cobalt ions were used for the colloidal silica film to having a good corrosion resistance and adhesion properties. It was thought that the film at 298K was made with combination of Si-O. The quantity of film formed at high temperature such as 333K and 353K is smaller than dissolved quantity during chemical conversion treatment. Adding $CoSO_4$ to the colloidal silica solution enhanced the adhesion force between the silica film and magnesium substrate, The optimum conditions for the chemical conversion treatment solution were PH 2.90 s treatment, and 298K.

Characteristics of Annealing Properties of Anti-pollution Coatings for the Cover Glass of PV Module (PV 모듈 커버글라스 오염방지 코팅의 열처리 특성분석)

  • Jung, Sejin;Lim, Yonnsik;Kim, Junghyun;Choi, Wonseok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.263-266
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    • 2017
  • In this study, the characteristics of anti-pollution coatings on glass substrates through annealing treatment were investigated. To investigate the change of properties by coating method and number of annealing treatment, after the anti-pollution coating was performed on the surface of glass substrate in three ways, the annealing treatment was performed by setting three kinds of annealing treatment conditions. The annealing treatment method is a torch using gas, which is advantage in that it can be installed directly on the site in an easy way compared with a annealing treatment process which is generally difficult. The anti-pollution properties, contact angle, transmittance, hardness, and adhesion of films on glass substrate were measured under 9 conditions of combination of coating methods and annealing treatment conditions. It was confirmed that as the number of annealing treatment increases, the anti-pollution property of the film synthesized on glass substrate becomes better.

Effects of Annealing Ambient on the Anti-Pollution and Mechanical Properties of Functional Film Coated on the Ceramic Substrate (세라믹 기판위에 코팅된 기능성 필름의 열처리 분위기에 따른 내오염 및 기계적 특성)

  • Shan, Bowen;Kang, Hyunil;Choi, Won Seok;Joung, Yeun-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.4
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    • pp.215-217
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    • 2016
  • For the improvement of the anti-pollution properties of porcelain electrical insulators, in this study, we have applied the functional film to the surface of insulator. The functional films were coated on the ceramic substrates which components were like the porcelain electrical insulator. The coating material was applied to ceramic substrate by spray coating method and then the film was cured at around $300^{\circ}C$ for 10 minutes with different gas ambient, such as $O_2$, $N_2$, and only vacuum. We have measured the contact angle of the coated surface, and obtained the lowest angle ($8.9^{\circ}$) and a strong hydrophilic property at vacuum condition. The anti-pollution properties were measured, revealing that as the contact angle decreased, the anti-pollution properties improved. The mechanical hardness and adhesion were both excellent regardless of the annealing ambient.

Improvement of anti-corrosive property for alloy plated steel sheet by UV curable organic-inorganic hybrid coatings (합금도금강판 내식성 향상을 위한 UV 경화형 유무기 하이브리드 코팅)

  • Park, Jongwon;Lee, Kyunghwang;Na, Hyunju;Park, Byungkyu;Nam, Yeungsub;Hong, Shinhyub
    • Corrosion Science and Technology
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    • v.12 no.1
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    • pp.27-33
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    • 2013
  • According to its merits about high curing speed and low emission of volatile organic compounds, UV curable inorganic-organic coating technology has been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. Based on the tetra-ethylorthosilicate(TEOS) and methacryloxypropyl trimethoxysilane(MPTMS), inorganic sol was synthesized and formed hybrid networks with UV curable acrylic monomer, 6-hexanediol diacrylate(HDDA), trimethylolpropane triacrylate(TMPTA), pentaerylthritol triacrylate(PETA). Several methods were used to test their properties such as salt spray test, potentiodynamic measurement, tape peel test, etc. It was shown that anti-corrosive property and stability of storage were affected by the molecular ratios of inorganic and organic compounds. It was not only the stability of storage, but had a excellent anti-corrosive, paint adhesive, and anti-solvent properties in a final molar ratios of 0.6/0.04/0.86/0.005 (TEOS/MPTMS/Acetone/HNO3) and 0.08/0.106/0.081/0.02 (TMPTA/HDDA/PETA/photo initiator).

Mechanisms of Platelet Adhesion on Elastic Polymer Surfaces: Protein Adsorption and Residence Effects

  • Insup Noh;Lee, Jin-Hui
    • Macromolecular Research
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    • v.9 no.4
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    • pp.197-205
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    • 2001
  • Platelet adhesion onto elastic polymeric biomaterials was tested in vitro by perfusing human whole blood at a shear rate of 100 sec$\^$-1/ for possible verification of mechanisms of initial platelet adhesion perfusion of blood on the polymeric substrates was performed after treatments either with or without pre-adsorption of 1% blood plasma, and either with or without residence of the protein-preadsorbed substrate in phosphate buffered solution. The surfaces employed were elastic polymers such as poly(ether urethane urea), poly(ether urethane), silicone urethane copolymer, silicone rubber and poly(ether urethane) with the anti-calcifying agent hydroxyethane bisphosphate. Each polymer surface treated was exposed in vitro to the dynamic, heparinized whole blood perfused for upto 6 min and the surface area of platelets initially adhered was measured by employing in situ epifluorescence video microscopy. The blood perfusion was performed on the surfaces treated at the following three different conditions: directly on the bare surfaces, after protein pre-adsorption and after residence in buffer for 3 days of the surfaces protein pre-adsorbed for 2 h. The effects of blood plasma pre-adsorption on the initial platelet adhesion was surface-dependent. The amount of the adsorbed fibrinogen and the surface coverage area of the adhered platelets were dependent on the surface conditions whether substrates were bare surfaces or protein pre-adsorbed ones. To test an effect of possible morphological (re)orientations of the adsorbed proteins on the initial platelet adhesion, the polymeric substrate pre-adsorbed with 1% blood plasma was immersed in phosphate buffered solution for 3 days and then exposed to physiological blood perfusion. The surface area of the platelets adhered on these surfaces was significantly different from that of the surfaces treated with protein pre-adsorption only. These results indicated that platelet adhesion was dependent on the surface property itself and pre-treatment conditions such as blood perfusion without any pre-adsorption of proteins, and blood perfusion either after protein pre-adsorption or after subsequent substrate residence in buffer of the substrate pre-adsorbed with proteins. Understanding of these results may guide for better designs of blood-contacting materials based on protein behaviors.

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Chromate-free Hybrid Coating for Corrosion Protection of Electrogalvanized Steel Sheets

  • Jo, Du-Hwan;Kwon, Moonjae;Kim, Jong-Sang
    • Corrosion Science and Technology
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    • v.11 no.1
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    • pp.15-19
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    • 2012
  • Both electrogalvanized and hot-dip galvanized steel sheets have been finally produced via organic-inorganic surface coating process on the zinc surface to enhance corrosion resistance and afford additional functional properties. Recently, POSCO has been developed a variety of chromate-free coated steels that are widely used in household, construction and automotive applications. New organic-inorganic hybrid coating solutions as chromate alternatives are comprised of surface modified silicate with silane coupling agent and inorganic corrosion inhibitors as an aqueous formulation. In this paper we have prepared new type of hybrid coatings and evaluated quality performances such as corrosion resistance, spot weldability, thermal tolerance, and paint adhesion property etc. The electrogalvanized steels with these coating solutions exhibit good anti-corrosion property compared to those of chromate coated steels. Detailed components composition of coating solutions and experimental results suggest that strong binding between organic-inorganic hybrid coating layer and zinc surface plays a key role in the advanced quality performances.

A study on the Property Evaluation of Waterproofinging and AntiCorrosion Systems Compositing Polymer Cement and Epoxy Resins (시멘트 혼입 폴리머와 에폭시수지를 복합한 상하수 시설용 방수${\cdot}$방식공법 성능평가에 관한 연구)

  • Bae Gi Sun;Jang Jong Ho;Jang Sung Joo;Oh Sang-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.164-167
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    • 2004
  • The purpose of this study is to investigate the properties of composite systems using polymer cement and epoxy resins for waterproofing and anti-corrosion to concrete structures such as water supply facilities and sewage-works. In this study these engineering properties of composite systems using polymer-modified mortar and epoxy resins were examined and could be confirmed to satisfy the guidelines of KS. Especially, it was turn out that the adhesion properties was excellent and high crack-resistance up to 1.49mm will be perform.

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Characterization and Antifungal Activity against Candida albicans of Vaginal Lactobacillus spp. Isolated from Korean Women (질 내 유산균의 Candida albicans에 대한 항진균 효과 연구)

  • Jung, Yeojung;Kang, Chang-Ho;Shin, YuJin;So, Jae-Seong
    • KSBB Journal
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    • v.32 no.2
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    • pp.146-152
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    • 2017
  • Vulvovaginal candidiasis (VVC) is one of the urogenital infections occurring in women worldwide. Candida albicans is generally observed among various types of microorganisms causing VVC. Antibiotic therapy is typical, and the use of Lactobacilli probiotics is to be recognized as a promising alternative. The aim of this study was to select vaginal lactobacilli with probiotic properties against C. albicans. In a previous study, we isolated 38 lactobacilli from vagina of Korean women and 20 isolates were shown to inhibit C. albicans. We further selected 10 isolates which were able to inhibit C. albicans less than $10^5CFU/mL$. Among these selected strains, Lactobacillus salivarius MG242 (identified by 16s rRNA sequencing) was finally selected based on its strong anti-candidal activity, acid/bile salt resistance and adhesion property. Indirect adhesion activity of MG242 measured by auto-aggregation assay showed more than 60% auto-aggregation after 5 h standing. Taken these results together, the selected strain MG242 may have potential for application in vagina health related products.

Screening and Characterization of Lactic Acid Bacteria Strains with Anti-inflammatory Activities through in vitro and Caenorhabditis elegans Model Testing

  • Lee, Hye Kyoung;Choi, Sun-Hae;Lee, Cho Rong;Lee, Sun Hee;Park, Mi Ri;Kim, Younghoon;Lee, Myung-Ki;Kim, Geun-Bae
    • Food Science of Animal Resources
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    • v.35 no.1
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    • pp.91-100
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    • 2015
  • The present study was conducted to screen candidate probiotic strains for anti-inflammatory activity. Initially, a nitric oxide (NO) assay was used to test selected candidate probiotic strains for anti-inflammatory activity in cultures of the murine macrophage cell line, RAW 264.7. Then, the in vitro probiotic properties of the strains, including bile tolerance, acid resistance, and growth in skim milk media, were investigated. We also performed an in vitro hydrophobicity test and an intestinal adhesion assay using Caenorhabditis elegans as a surrogate in vivo model. From our screening, we obtained 4 probiotic candidate lactic acid bacteria (LAB) strains based on their anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell cultures and the results of the in vitro and in vivo probiotic property assessments. Molecular characterization using 16S rDNA sequencing analysis identified the 4 LAB strains as Lactobacillus plantarum. The selected L. plantarum strains (CAU1054, CAU1055, CAU1064, and CAU1106) were found to possess desirable in vitro and in vivo probiotic properties, and these strains are good candidates for further investigations in animal models and human clinical studies to elucidate the mechanisms underlying their anti-inflammatory activities.