• Title/Summary/Keyword: chemical surface treatment

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Filler-Elastomer Interactions. 3. Microstructures and Mechanical Interfacial Properties of Anodized Carbon Black/Rubber Composites

  • Park, Soo-Jin;Kim, Jeong-Soon;Lee, Jae-Rock
    • Carbon letters
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    • v.1 no.3_4
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    • pp.138-142
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    • 2001
  • The effect of electrochemical surface treatments in KOH chemical solution on microstructures of carbon blacks was investigated in terms of surface functional values and XRD measurements. And their mechanical interfacial properties of the carbon blacks/rubber composites were studied by the composite tearing energy ($G_{IIIC}$). It was found that the development of basic-surface functional groups lead to the significant physical changes of carbon blacks, such as, decrease of the interlayer spacing ($d_{002}$), increase of the crystalline size along c-axis ($L_c$), and increase of degree of crystalline (${\chi}_c$). This treatment is possibly suitable for carbon blacks to be incorporated in a hydrocarbon rubber matrix, resulting in improving the hardness and tearing energy of the resulting composites.

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Effects of chemical modification on surface characteristics and 2,4-dichlorophenol adsorption on activated carbon (활성탄 개질에 따른 표면 특성 변화가 2,4-dichlorophenol 흡착성능에 미치는 영향)

  • An, Sun-Kyung;Song, Won-Jung;Park, Young-Min;Yang, Hyeon-A;Kweon, Ji-Hyang
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.6
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    • pp.425-435
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    • 2020
  • Numerous chemical modifications on activated carbon such as acidic conditioning, thermal treatment and metal impregnation have been investigated to enhance adsorption capacities of micropollutants in water treatment plants. In this study, chemical modification including acidic, alkaline treatment, and iron-impregnation was evaluated for adsorption of 2,4-dichlorophenol (2,4-DCP). For Fe-impregnation, three concentrations of ferric chloride solutions, i.e., 0.2 M, 0.4 M, and 0.8 M, were used and ion-exchange (MIX) of iron and subsequent thermal treatment (MTH) were also applied. Surface properties of the modified carbons were analyzed by active surface area, pore volume, three-dimensional images, and chemical characteristics. The acidic and alkaline treatment changed the pore structures but yielded little improvement of adsorption capacities. As Fe concentrations were increased during impregnation, the active adsorption areas were decreased and the compositional ratios of Fe were increased. Adsorption capacities of modified ACs were evaluated using Langmuir isotherm. The MIX modification was not efficient to enhance 2,4-DCP adsorption and the MES treatment showed increases in adsorption capacities of 2,4-DCP, compared to the original activated carbon. These results implied a possibility of chemical impregnation modification for improvement of adsorption of 2,4-DCP, if a proper modification procedure is sought.

Hydrogen Adsorption of Acid-treated Multi-walled Carbon Nanotubes at Low Temperature

  • Lee, Seul-Yi;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1596-1600
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    • 2010
  • Surface functionalization of multi-walled carbon nanotubes (MWNTs) was carried out by means of acid treatment. The presence of oxygen functional groups on the surface of acid-treated MWNTs was confirmed with the aid of Fourier transform infrared spectroscopy and X-ray spectroscopy. In addition, carboxylic groups generally formed on the surface of acid-treated MWNTs, and the dispersion was increased by the duration of the acid treatment. The zeta-potential indicated the surface charge transfer and the dispersion of MWMTs. Morphological characteristics of acid-treated MWNTs were also observed using a transmission electron microscopy, X-ray diffraction, and Raman analysis, which was revealed the significantly unchanged morphologies of MWNTs by acid treatment. The hydrogen adsorption capacity of the MWNTs was evaluated by means of adsorption isotherms at 77 K/1 atm. The hydrogen storage capacity was dependent upon the acid treatment conditions and the formation of oxygen functional groups on the MWNT surfaces. The latter have an important effect on the hydrogen storage capacity.

Treatment of surface water using cold plasma for domestic water supply

  • Nguyen, Dung Van;Ho, Phong Quoc;Pham, Toan Van;Nguyen, Tuyen Van;Kim, Lavane
    • Environmental Engineering Research
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    • v.24 no.3
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    • pp.412-417
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    • 2019
  • This paper presents the results of using cold plasma to treat surface water for domestic use purpose. Experimental results showed that cold plasma was an effective method for destroying bacteria in water. After treatment with cold plasma, concentration of coliform and Escherichia coli dramatically reduced. Besides, cold plasma significantly removed water odor, increased dissolved oxygen and decreased the concentration of chemical oxygen demand. However, cold plasma significantly raised the concentration of nitrite and nitrate. Other disadvantages of treating with cold plasma were conductivity increase and pH reduction. Pretreatment steps of coagulation, flocculation, sedimentation and sand filtration followed by disinfection with cold plasma exhibited a high efficiency in surface water treatment. All parameters of surface water after treatment by using the prototype satisfied with the allowance standard of domestic water quality.

Effect of Surface Treatment on Hydrogen Production of Cadmium Sulfide Particulate Film Electrodes (수소제조용 CdS 입자막 전극의 표면처리 효과)

  • Jang, Jum-Suk;Chang, Hye-Young;So, Won-Wook;Rhee, Young-Woo;Moon, Sang-Jin
    • Transactions of the Korean hydrogen and new energy society
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    • v.11 no.3
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    • pp.119-125
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    • 2000
  • To improve the photochemical energy conversion efficiency and the stability of CdS particulate film electrode which is used to produce hydrogen from the aqueous $H_2S$ solution photoelectrochemically, surface treatment of this film was carried out using $TiCl_4$ solution. CdS particles for preparation of the films were synthesized by precipitation reaction of $Cd({NO_3})_2{\cdot}9H_2O$ and $Na_2S{\cdot}4H_2O$. Then, the CdS sol was hydrothermally treated for 12hr in an autoclave with the variation of treatment temperature to control the crystalline phase of particles. CdS film electrode was thus prepared by annealing at $400^{\circ}C$ for 12hr of the wet-film cast at room temperature, and subsequently surface treated with $TiCl_4$ solution. The electrodes were characterized using XRD, SEM, and the photocurrent meter. The photocurrents of Cds film electrodes prepared with surface treatment were up to two times higher than the electrodes without surface treatment, indicating about $4.0mA/cm^2$. Hydrogen production rate in a continuous flow system using photoelectrochemical or photochemical cells prepared with surface treatment also increased in proportion to the increase of photocurrents.

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Surface analysis of PET films by XPS and surface potential decay (XPS와 표면전위감소 통한 PET 필름의 표면분석)

  • Lim, K.B.;You, D.H.;Lee, B.J.;Lee, B.S.;Lee, S.H.;Shin, T.H.;Shin, P.K.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1682-1684
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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 resistivity was measured to analyze the electrical characteristic. When plasma discharge treatment was conducted for less than 10 minutes, the electrical insulating property was found to be improved through 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. Analysis of chemical characteristics showed that 10-minute treatment resulted in increase of C-O and O=C-O. However, when treated for more than 10 minutes, they were relatively decreased.

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A Study of a Changing of Physical and Chemical Intra-structure on Si-DLC Film during Tribological Test (실리콘 함유 DLC 박막의 마찰마모 시험에 의한 물리적 특성 및 화학적 결합 구조 변화 고찰)

  • Kim, Sang-Gweon;Lee, Jae-Hoon;Kim, Sung-Wan
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.3
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    • pp.127-132
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    • 2011
  • The silicon-containing Diamond-like Carbon (Si-DLC) film as an low friction coefficient coating has especially treated a different silicon content by plasma-enhanced chemical vapor deposition (PECVD) process at $500^{\circ}C$ on nitrided-STD 11 mold steel with (TMS) gas flow rate. The effects of variable silicon content on the Si-DLC films were tested with relative humidity of 5, 30 and 85% using a ball-on-disk tribometer. The wear-tested and original surface of Si-DLC films were analysed for an understanding of physical and chemical characterization, including a changing structure, via Raman spectra and nano hardness test. The results of Raman spectra have inferred a changing intra-structure from dangling bonds. And high silicon containing DLC films have shown increasing carbon peak ratio ($I_D/I_G$) values and G-peak values. In particular, the tribological tested surface of Si-DLC was shown the increasing hardness value in proportional to TMS gas flow rate. Therefore, at same time, the structure of the Si-DLC film was changed to a different intra-structure and increased hardness film with mechanical shear force and chemical reaction.

Improvement of Plating Characteristics Between Nickel and PEEK by Plasma Treatment and Chemical Etching

  • Lee, Hye W.;Lee, Jong K.;Park, Ki Y.
    • Corrosion Science and Technology
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    • v.8 no.1
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    • pp.15-20
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    • 2009
  • Surface of PEEK(poly-ether-ether-ketone) was modified by chemical etching, plasma treatment and mechanical grinding to improve the plating adhesion. The plating characteristics of these samples were studied by the contact angle, plating thickness, gloss and adhesion. Chemical etching and plasma treatment increased wettability, adhesion and gloss. The contact angle of as-received PEEK was $61^{\circ}$. The contact angles of chemical etched, plasma treated or both were improved to the range of $15{\sim}33^{\circ}$. In the case of electroless plating, the thickest layer without blister was $1.6{\mu}m$. The adhesion strengths by chemical etching, plasma treatment or both chemical etching and plasma treatment were $75kgf/cm^2$, $102kgf/cm^2$, $113kgf/cm^2$, respectively, comparing to the $24kgf/cm^2$ of as-received. In the case of mechanically ground PEEKs, the adhesion strengths were higher than those unground, with the sacrifice of surface gloss. The gloss of untreated PEEK were greater than mechanically ground PEEKs. Plating thickness increased linearly with the plating times.

New Evaluation System of Cosmetic Effects on Morphology of Skin Surface Using TSRLM with Image Analyser

  • Kim, Jong-Il;Lee, Joa-Hoon;Lee, Yoo-Young;Kim, Chang-Kew
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.16 no.1
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    • pp.47-63
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    • 1990
  • Image analyser was used to understand the condition of skin surface and to evaluate the efficacy of cosmetic treatment. It was unsatisfactory to analyse skin surface structure although several methods using image analyser had been presented. We developed the new system composed of image analyser and Tandem Scanning Reflected Light Microscope (TSRLM) having the remarkable optical sectioning property as image input device. By using this new system, we quantitatively measured the change of skin surface, the depth and width of furrow in micron unit, resulted by cosmetic treatments. And also three dimensional image of skin was reconstructed with serial sectioned images, which were captured through TSRLM, for better understanding of the effect of cosmetic treatment. It was found that skin relief was more easily understood and the change of skin surface caused by cosmetic treatment was more accurately measured by using this system. In addition, we was also aware of the possibility of in vivo direct measurement of skin furrow without replica. It was conceivable that our system could be applicable for study of cosmetic effects further.

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Modification methods of polyethersulfone membranes for minimizing fouling - Review

  • Sathish Kumar, R.;Arthanareeswaran, G.;Paul, Diby;Kweon, Ji Hyang
    • Membrane and Water Treatment
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    • v.6 no.4
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    • pp.323-337
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    • 2015
  • Membrane Fouling was considered as major drawback in various industrial applications. Thus, this paper reviews the surface modification of polyethersulfone (PES) membranes for antifouling performance. Various modification techniques clearly indicate that hydrophilicity has to improve on the PES membrane surface. Moreover, the mechanism of fouling reduction with corresponds to various modification methods is widely discussed. Incorporation of hydrophilic functional groups on PES membrane surface enhances the surface free energy thereby which reduces the fouling. Characterization techniques adopted for the surface modified membranes was also discussed. These studies might be useful for the other researchers to utilize the modification technique for the applications of waste water treatment, chemical process industry and food industry.