• Title/Summary/Keyword: surface chemical analyses

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Surface Modification of PET Irradiated by Ultra-Violet (Part I) -Transformation of Chemical Structure and Surface Properties- (UV조사를 통한 PET의 표면개질 (제1보) -화학구조 변화 및 표면특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.3_4 s.141
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    • pp.561-568
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    • 2005
  • The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

Topological Study of the Behavior of Inorganic Fine Powers and a Nanovesicle Hybridized Coating

  • Seo, Dong-Sung;Kim, Dong-Pyo;Jin, Fan-Long;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.343-347
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    • 2009
  • In this study, the surface of inorganic fine powders is hybridized with nanovesicles containing tocopheryl acetate prepared with hydrogenated lecithin via a coating process. From AFM and SEM analyses it is found that the surface of the nanovesicle-coated fine powders lost their traditional topology and improved in terms of their roughness, skewness, and kurtosis. In addition, TEM observations revealed the formation of a 5 nm thick coating layer on the surface of the fine powders. These hybridized powders, in which bioactive materials such as tocopheryl acetate can be embedded, can be employed as a part of a drug delivery system due to their special ability to control release rate and temperature selectivity. Physical properties of the powders, i.e., the different angle and friction coefficient, were excellent.

Detection of Escherichia coli O157:H7 Using Immunosensor Based on Surface Plasmon Resonance

  • Oh, Byung-Keun;Kim, Young-Kee;Bae, Young-Min;Lee, Won-Hong;Choi, Jeong-Woo
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.780-786
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    • 2002
  • An immunosensor based on surface plasmon resonance (SPR) with a self-assembled protein G layer was developed for the detection of Escherichia coli O157:H7. A self-assembled protein C layer on a gold (Au) surface was fabricated by adsorbing the mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol at various molar ratios and by activating chemical binding between free amine (-$NH_2$) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) in series. The formation of a self-assembled protein G layer on an Au substrate and the binding of the antibody and antigen in series were confirmed by SPR spectroscopy. The surface morphology analyses of the self-assembled protein G layer on the Au substrate, monoclonal antibody (Mab) against E. coli O157:H7 which was immobilized on protein G, and bound E. coli O157:H7 extracts on Immobilized Mab against E. coii O157:H7 were performed by atomic force microscopy (AFM). The detection limit of the SPR-based immunosensor for E. coli O157:H7 was found to be about $10^4$ cells/ml.

Control of Surface Chemistry and Electrochemical Performance of Carbon-coated Silicon Anode Using Silane-based Self-Assembly for Rechargeable Lithium Batteries

  • Choi, Hyun;Nguyen, Cao Cuong;Song, Seung-Wan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2519-2526
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    • 2010
  • Silane-based self-assembly was employed for the surface modification of carbon-coated Si electrodes and their surface chemistry and electrochemical performance in battery electrolyte depending on the molecular structure of silanes was studied. IR spectroscopic analyses revealed that siloxane formed from silane-based self-assembly possessed Si-O-Si network on the electrode surface and high surface coverage siloxane induced the formation of a stable solid-electrolyte interphase (SEI) layer that was mainly composed of organic compounds with alkyl and carboxylate metal salt functionalities, and PF-containing inorganic species. Scanning electron microscopy imaging showed that particle cracking were effectively reduced on the carbon-coated Si when having high coverage siloxane and thickened SEI layer, delivering > 1480 mAh/g over 200 cycles with enhanced capacity retention 74% of the maximum discharge capacity, in contrast to a rapid capacity fade with low coverage siloxane.

A Study on the Surface Analysis of Plasma-Treated PET Film (플라즈마 처리된 PET 필름의 표면분석에 관한 연구)

  • Lim Kyung-Bum;Choi Hoon-Young;Lee Seok-Hyun;Lee Duck-Chool
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.12
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    • pp.596-600
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    • 2004
  • In this study, the surface properties of PET film were analyzed after plasma surface treatment. After plasma treatment of surface roughness and XPS were evaluated to analyze the chemical property, while the surface potential decay and surface resistance rate was measured to analyze the electric관 characteristic. When plasma discharge treatment was conducted for less than 10 minutes, the electrical insulating property was improved by evaporation of low molecular weight materials and cleaning of surface. However, when the treatment was conducted for more than 10 minutes, the insulating property was decreased due to excessive discharge energy. Analyses of chemical characteristics showed that 10-minute treatment resulted in increase of C-O and O=C-O bonds. However, when treated for more than 10 minutes. they were relatively decreased.

Synthesis of Ultrafine Powders for Aluminum Nitride by DC Thermal Plasma (직류 열플라즈마를 이용한 질화알루미늄 초미세분말의 합성)

  • 안현;허민;홍상희
    • Journal of the Korean institute of surface engineering
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    • v.29 no.1
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    • pp.45-59
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    • 1996
  • Ultrafine powders(UFPs) of aluminum nitride(AlN) have been synthesized by chemical reactions in the nitrogen atmosphere and the gaseous aluminum evaporated from Al powders in thermal plasmas produced by a DC plasma torch. A synthesis system consisting of a plasma torch, a finely-controllable powder feeder, a reaction chamber, and a quenching-collection chamber have been designed and manufactured, and a filter for gathering AlN UFPs produced by the quenching process subsequent to the synthesis is set up. The synthesis process is interpreted by numerical analyses of the plasma-particle interaction and the chemical equilibrium state, respectively, and a fully-saturated fractional factorial test is used to find the optimum process conditions. The degrees and ultrafineness of synthesis are evaluated by means of SEM, TEM, XRD, and ESCA analyses. AlN UFPs synthesized in the optimum process conditions have polygonal shapes of the size of 5-100 nm, and their purities differ depending on collecting positions and filter types, and the maximum purity obtained is 72 wt% at the filter.

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An Empirical Relation between the Plating Process and Accelerator Coverage in Cu Superfilling

  • Cho, Sung-Ki;Kim, Myung-Jun;Koo, Hyo-Chol;Kim, Soo-Kil;Kim, Jae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1603-1607
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    • 2012
  • The effects of plating process on the surface coverage of the accelerator were investigated in terms of Cu superfilling for device metallization. When a substrate having 500 nm-wide trench patterns on it was immersed in an electrolyte containing poly (ethylene glycol) (PEG)-chloride ion ($Cl^-$)-bis(3-sulfopropyl) disulfide (SPS) additives without applying deposition potential for such a time of about 100s, voids were generated inside of the electrodeposit. In time-evolved electrochemical analyses, it was observed that the process (immersion without applying potential) in the electrolyte led to the build-up of high initial coverage of SPS-Cl on the surface, resulting in the fast saturation of the coverage. Repeated experiments suggested that the fast saturation of SPS-Cl failed in superfilling while a gradual increase in the SPS-Cl coverage through competition with initially adsorbed PEG-Cl enabled it. Consequently, superfilling was achievable only in the case of applying the plating potential as soon as the substrate is dipped in an electrolyte to prevent rapid accumulation of SPS-Cl on the surface.

CHARACTERISTICS OF RESIDUAL CARBON DERIVED FROM THE COMBUSTION OF VACUUM RESIDUE IN A TEST FURNACE

  • Park, Ho-Young;Seo, Sang-Il
    • Environmental Engineering Research
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    • v.12 no.3
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    • pp.109-117
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    • 2007
  • The characteristics of carbonaceous particles collected from the combustion of Vacuum Residue (VR) in a test furnace have been investigated. The physical and chemical characterization includes particle size, scanning electron microscopy of the surface structure, measurement of porosity, surface area and density, EDX/XRD analyses and measurement of chemical composition. The studies show that the carbonaceous VR particles are very porous and spheroidal, and have many blow-holes on the surface. The particles become smaller and more sponge-like as the reaction proceeds. The present porosity of VR particles is similar to that of cenospheres from the combustion of heavy oil, and the majority of pores are distributed in macro-pores above $0.03\;{\mu}m$ in diameter. Measurements of pore distribution and surface area showed that the macro-pores contributed most to total pore volume, whereas the micro-pores contributed to total surface area.

Mechanism of Wrinkle Formation on Styrene-Butadiene-Styrene Block Copolymer via Ion-Beam Irradiation (Styrene-Butadiene-Styrene Block Copolymer 위 이온빔 조사를 이용한 주름 구조 생성 메커니즘 연구)

  • Lee, Ju Hwan;Kim, Dai-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.34 no.2
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    • pp.130-135
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    • 2021
  • Wrinkle patterns were fabricated on styrene-butadiene-styrene (SBS) block copolymer substrates using ion-beam (IB) irradiation with various intensities. The wavelength of the wrinkle pattern increased as the IB intensity was increased from 800 to 1,600 eV. IB irradiation-induced changes in the surface properties that were confirmed via physicochemical surface analyses. X-ray photoelectron spectroscopy analysis revealed chemical surface reformation due to the IB irradiation, resulting in C-O/C=O bonds after IB irradiation that were not reported before. These results indicate that the surface chemical modification caused by IB irradiation is strongly related to the surface modulus, which is important when fabricating wrinkle patterns. Furthermore, a strong IB irradiation induced a strong compressive strain; thus the size of the wrinkle pattern was increased.

Characterization of Anodized Al 1050 with Electrochemically Deposited Cu, Ni and Cu/Ni and Their Behavior in a Model Corrosive Medium

  • Girginov, Christian;Kozhukharov, Stephan;Tsanev, Alexander;Dishliev, Angel
    • Journal of Electrochemical Science and Technology
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    • v.12 no.2
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    • pp.188-203
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    • 2021
  • The specific benefits of the modified films formed on preliminary anodized aluminum, including the versatility of their potential applications impose the need for evaluation of the exploitation reliability of these films. In this aspect, the durability of Cu and Ni modified anodized aluminum oxide (AAO) films on the low-doped AA1050 alloy was assessed through extended exposure to a 3.5% NaCl model corrosive medium. The electrochemical measurements by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic scanning (PDS) after 24 and 720 hours of exposure have revealed that the obtained films do not change their obvious barrier properties. In addition, supplemental analyses of the coatings were performed, in order to elucidate the impact of the AC-deposition of Cu and Ni inside the pores. The scanning electron microscopy (SEM) images have shown that the surface topology is not affected and resembles the typical surface of an etched metal. The subsequent energy dispersive X-ray spectroscopy (EDX) tests have revealed a predominance of Cu in the combined AAO-Cu/Ni layers, whereas additional X-ray photoelectron (XPS) analyses showed that both metals form oxides with different oxidation states due to alterations in the deposition conditions, promoted by the application of AC-polarization of the samples.