• Title/Summary/Keyword: Ethylene oxide

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Hydrophilic Modification of Poly(ethylene oxide) by UV Irradiation

  • Koo, Gwang-Hoe;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.21 no.5
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    • pp.16-20
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    • 2009
  • Films of Poly(ethylene oxide), PEO, were modified to impart hydrophilicity via UV irradiation. The UV irradiation treatment produced new photo-oxidized groups of carbonyl and ether groups as indicated in ATR and ESCA analysis. It was found that water contact angle decreased from $15^{\circ}C$ to $10^{\circ}C$ and total surface energy of PEO increased from 54.2 mN/m to 76.6 mN/m with increasing UV energy, which was attributed to significant contribution of acid base interaction of the photo-oxidized PEO rather than nonpolar interaction originating from the dominant increase in Lewis acid parameter. The increased hydrophilicity and surface energy were also proved by the decreased water wetting time.

Conductivity properties of ion conducting polymer electrolyte based on poly(ethylene oxide) (이온전도성 poly(ethylene oxide)고분자전해질의 전도특성)

  • 김종욱;문성인;진봉수;구할본;윤문수
    • Electrical & Electronic Materials
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    • v.8 no.4
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    • pp.487-494
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    • 1995
  • The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li secondary battery. We investigated the effects of lithium salts, plasticizer addition, temperature dependence of conductivity and electrochemical stability window of polyethylene oxide(PEO) electrolytes. PEO electrolyte completed with LiCIO$\_$4/ shows the better conductivity than the others. PEO-LiCIO$\_$4/ electrolyte, when EO/Li$\^$+/ ratio is 8, showed adequate conductivity around room temperature. By adding propylene carbonate and ethylene carbonate to PEO-LiCIO$\_$4/ electrolyte, its conductivity was higher than that of PEO-LiCIO$\_$4/ without those. Also PEO$\_$8/LiCIO$\_$4/ electrolyte remains stable up to 4.5V vs. Li/Li.

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A preparation of dysprosium monotitanate powder by mixed-oxide ceramics processing employing polymer carrier (Polymer carrier 효과에 의하여 단순화된 새로운 세라믹분말 제조방법)

  • 이상진
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.2
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    • pp.350-355
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    • 1998
  • Dysprosium monotitanate $(Dy_2TiO_5)$ powder was synthesized by a simple mixed-oxide ceramics process using ethylene glycol (EG). Ethylene glycol, as the organic carrier for the metal cations, was used for polymerization mechanism. The successful used of a non-chelating polymer for the mixed-oxide ceramic process indicated that cation chelation is not the only route for creating stable ceramic precursors. Characterization of the powders by various thermal analysis, microscopy, and diffraction methods has been carried out.

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Mechanical degradation kinetics of poly(ethylene oxide) in a turbulent flow

  • Sung, Jun-Hee;Lim, Sung-Taek;Kim, Chul-Am;Heejeong Chung;Park, Hyoung-Jin
    • Korea-Australia Rheology Journal
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    • v.16 no.2
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    • pp.57-62
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    • 2004
  • Turbulent drag reduction (DR) efficiency of water soluble poly(ethylene oxide) (PEO) with two different molecular weights was studied as a function of polymer concentration and temperature in a turbulent flow produced via a rotating disk system. Its mechanical degradation behavior as a function of time in a turbulent flow was also analyzed using both a simple exponential decay function and a fractional exponential decay equation. The fractional exponential decay equation was found to fit the experimental data better than the simple exponential decay function. Its thermal degradation further exhibited that the susceptibility of PEO to degradation increases dramatically with increasing temperature.

Water and oxygen permeation through transparent ethylene vinyl alcohol/(graphene oxide) membranes

  • Kim, Hye Min;Lee, Heon Sang
    • Carbon letters
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    • v.15 no.1
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    • pp.50-56
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    • 2014
  • We prepared ethylene vinyl alcohol (EVOH)/graphene oxide (GO) membranes by solution casting method. X-ray diffraction analysis showed that GOs were fully exfoliated in the EVOH/GO membrane. The glass transition temperatures of EVOH were increased by adding GOs into EVOH. The melting temperatures of EVOH/GO composites were decreased by adding GOs into EVOH, indicating that GOs may inhibit the crystallization of EVOH during non-isothermal crystallization. However, the equilibrium melting temperatures of EVOH were not changed by adding GOs into EVOH. The oxygen permeability of the EVOH/GO (0.3 wt%) film was reduced to 63% of that of pure EVOH film, with 84% light transmittance at 550 nm. The EVOH/GO membranes exhibited 100 times better (water vapor)/(oxygen) selectivity performance than pure EVOH membrane.

Comparative Effects of Gamma Irradiation and Ethylene Oxide Fumigation on Antioxidant Activity of White Ginseng Powder (백삼분말의 항산화 활성에 대한 감마선과 에틸렌옥사이드 처리의 영향)

  • 한용남;김선영
    • Journal of Ginseng Research
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    • v.19 no.3
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    • pp.231-236
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    • 1995
  • The antioxidant activity and the pharmacologically active constituents such as nucleosides and phenolic substancs of Panax ginseng C.A. Meyer (white ginseng powder) treated with gamma irradiation (Rl group) and ethylene oxide fumigation (EO group) were compared with those of non-treated ginseng (control group). High performance liquid chromatograms of nucleosides in three groups were similar with each other. The bathochromic effect of phenolic substances at W absorption region tends to be higher for EO group than Rl group. This tendency was also observed in heat treatment of each group. However, the antioxidant activity may have some effects on the labile property of phenolic substances. In summary the gamma-irradiated ginseng was more stable than the ethylene oxide-treated ginseng, but both ginseng samples gave the similar antioxidant activity.

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Component Profile Analysis of Irradiated Korean White Ginseng Powder (방사선 조사 인삼의 성분변화에 관한 분석)

  • 한병훈;한용남
    • Journal of Ginseng Research
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    • v.19 no.2
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    • pp.138-143
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    • 1995
  • Currently, some food materials are disinfected by $\gamma$-irradiation (using Co-60) or ethylene oxide treatment. These treatments were applied to ginseng powder and the ginseng components such as ginsenosides, polyacetylenes and phenolic acids were analyzed by HPLC to determine any compositional changes due to irradiation. No appreciable difference was observed in the HPLC pattern of ginsenosides, polyacetylenes of ginseng powder after 10 key irradiation or ethylene oxide treatment (EO $CO_2$= 3 : 7, w/wfb) from those of untreated fresh ginseng powder when they were analyzed soon after treatments. When the ginseng powders were stored at room temperature for three years after the same treatment, the HPLC patterns of polyacetylenes and phenolic acid fraction showed appreciable change from those of fresh ginseng powder, however, the HPLC patterns of three year old samples did not show any appreciable difference.

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A Comparative Study of Radiation and Gas Sterilization. (방사선항균법과 개스항균법의 비교연구)

  • 정해원;유영수
    • Journal of Environmental Health Sciences
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    • v.8 no.1
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    • pp.81-97
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    • 1982
  • Ethylene oxide gas has been used as a cold sterilant for heat-sensitive medical equipments and as a fumigant for food for more than 30 years, and it is used more widely than radiation although radiation sterilization has made significant inroads in recent years. But according to recent studies of toxicities such as mutagenicity, haemolytic effect and possible carcinogenicity of Ethylene oxide (ETO) and its two main reaction products, Ethylene chlorohydrin (ETCH) and Ethylene glycol (ETG), Environmental Protection Agency in U.S.A. has suggested some regulations on residual gas in drug products and medical devices for human use. The mutagenic activity of ETO compared with that of X-ray has an equivalency of 1 ppm/hr for ETO as compared to 20 mrad for X-ray, and one could suggest the present maximum allowable concentration for ETO (50 ppm) should be 400 times lower than the radiation standard (2.5 mrad/hr). Although radiation sterilization has advantages of simplicity of operation and complete reliability, changes of physico-chemical properties with possible formation of toxic substances may occur. It is therefore necessary to make some regulations of our own for residual toxicities orginated from each sterilization method.

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Determination of the Residual Ethylene Oxide in Quasi-drugs (의약외품중 산화에칠렌가스의 잔류량 분석)

  • 이정표;김경옥;손경훈;양성준;백옥진
    • YAKHAK HOEJI
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    • v.45 no.5
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    • pp.437-441
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    • 2001
  • The quasi-drugs including nonwoven fabric and gauze were sterilized using ethylene oxide (EO) gas. Residual EO in the quasi-drugs was extracted with water (20 mL of water for 1 g of sample) for 24h at 37$^{\circ}C$. Residual EO was determined using GC. The optimal analytical conditions were as follows : column, Carbowax 20M (1.D. 0.2 mm); mobile phase, helium with 30 mL/min; oven temperature 57$^{\circ}C$, injector temperature 18$0^{\circ}C$, detector temperature 20$0^{\circ}C$. The detection limit for EO was 0.10$\mu$g/mL. When the residual EO extracted from nonwoven fabric and gauze was determined, it took more than 9h to get the lower level than 25 ppm which is the limit value of FDA guideline. When the EO residues, ethylene chlorohydrine (ECH) and ethylene glycol (EG) in the 7 commercially available quasi-drugs were determined, no residual EO, ECH, EG were found from the seven commercially available quasi-drugs analyzed by this method.

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Oxidation of Ethylene over $Ag/{\alpha}-Al_2O_3Ag/SnO_2$ ($Ag/{\alpha}-Al_2O_3Ag/SnO_2$ 촉매상에서의 에틸렌 산화반응)

  • Jun Ki-Won;Chong-Soo Han;Hakze Chon
    • Journal of the Korean Chemical Society
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    • v.28 no.2
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    • pp.109-113
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    • 1984
  • The effects of various supports on the activity and the selectivity for the ethylene oxidation was investigated over$ Ag/{\alpha}-Al_2O_3$ and $Ag/SnO_2$ by Auger, EPR spectroscopy and reaction studies. The results indicate that over $Ag/SnO_2$ catalyst O- chemisorbed on $SnO_2 $participates in the complete oxidation of ethylene lowering the selectivity for the formation of ethylene oxide.

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