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Sample records for chloromethyl methyl ether

  1. Chloromethylation of Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Poly(ether ether ketone) (PEEK) is a high-performance engineering thermoplastic with good thermal stability, high chemical resistance and excellent mechanical properties. Chloromethylation reaction is one of the classical methods to introduce functional groups into polymers, because the chloromethyl group can be converted to many functional groups, such as - CH2 (CH3) + Cl.

  2. Synthesis and characterization of quaternized poly(phthalazinone ether sulfone ketone) for anion-exchange membrane

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quatemized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance,which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.

  3. MICRON CORE-SHELL PARTICLES PREPARED BY GRAFTING POLYMERIZATION OF METHYL METHACRYLATE FROM NARROW DISPERSE SURFACE OF CHLOROMETHYLATED POLYDIVINYLBENZENE VIA ATRP

    Institute of Scientific and Technical Information of China (English)

    Yu-zeng Zhao; Xin-lin Yang; Wen-qiang Huang

    2005-01-01

    Grafting of poly(methyl methacrylate) from narrow disperse polymer particles by surface-initiated atom transfer radical polymerization (ATRP) was investigated. Polydivinylbenzene (PDVB) particles were prepared by dispersion polymerization with poly(N-vinyl pyrrolidone) (PVP) as the stabilizer. Chloromethylated PDVB was used as initiating core sites for subsequent ATRP of methyl methacrylate with CuBr/bpy as catalyst system. It was found that poly(methyl methacrylate) was grafted not only from the particle surfaces but also from within a thin shell layer, leading to particles size increases from 2.38-3.00 μm with a core-shell structure particles. The grafted core-shell particles were characterized with FTIR, SEM, DSC.

  4. A Facile Synthesis of Two Sesquiterpenes Methyl Ether

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Ting; ZHANG Yan-Mei; WANG Zi-Kun; WU Tong-Xing; PAN Xin-Fu

    2003-01-01

    @@ Bisabolane sesquiterpenes are a big family of naturally occurring products with significantly biological activities most of which can be separated from Chinese traditional medicines. Parahigginone (1a) was firstly separated as a bisabolane by Shen Y. C. et al. from the Taiwan marine sponges in 1999, [1] it shows very promising antitumor activity.[1] As far as we know, there is no synthetic report on it. Curcuphenol (2a) was a cytotoxic sesquiterpene which was first discovered in Pseudopterogorgia rigida[2,3] which has been synthesized by Frank[2] and Tsutomu[4] before. In order to study the relationship between the structures and the activities, we have synthesized parahiggi none methyl ether (1) and curcuphenol methyl ether (2) in six steps successfully, and the stereoselective synthesis is carried out in progress.

  5. Alternariol 9-O-methyl ether

    Directory of Open Access Journals (Sweden)

    Brett A. Neilan

    2012-05-01

    Full Text Available The title compound (AME; systematic name: 3,7-dihydroxy-9-methoxy-1-methyl-6H-benzo[c]chromen-6-one, C15H12O5, was isolated from an endophytic fungi Alternaria sp., from Catharanthus roseus (common name: Madagascar periwinkle. There is an intramolecular O—H...O hydrogen bond in the essentially planar molecule (r.m.s. deviation 0.02 Å. In the crystal, the molecule forms an O—H...O hydrogen bond with its centrosymmetric counterpart with four bridging interactions (two O—H...O and two C—H...O. The almost planar sheets of the dimeric units thus formed are stacked along b axis via C—H...π and π–π contacts [with C...C short contacts between aromatic moieties of 3.324 (3, 3.296 (3 and 3.374 (3 Å].

  6. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Science.gov (United States)

    2011-11-09

    ... AGENCY 40 CFR Part 180 Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether... residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft... permissible level for residues of methacrylic acid-methyl methacrylate-polyethylene glycol monomethyl...

  7. Biodegradation of ethyl t-butyl ether (ETBE), methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) by Gordonia terrae.

    Science.gov (United States)

    Hernandez-Perez, G; Fayolle, F; Vandecasteele, J P

    2001-01-01

    Gordonia terrae strain IFP 2001 was selected from activated sludge for its capacity to grow on ethyl t-butyl ether (ETBE) as sole carbon and energy source. ETBE was stoichiometrically degraded to t-butyl alcohol (TBA) and the activity was inducible. A constitutive strain, G. terrae IFP 2007, derived from strain IFP 2001, was also selected. Methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) were not used as carbon and energy sources by the two strains, but cometabolic degradation of MTBE and TAME was demonstrated, to TBA and t-amyl alcohol (TAA) respectively, in the presence of a carbon source such as ethanol. No two-carbon compound was detected during growth on ETBE, but formate was produced during cometabolic degradation of MTBE or TAME. A monooxygenase was involved in the degradation of ethers, because no degradation of ETBE was observed under anaerobic conditions and the presence of a cytochrome P-450 was demonstrated in G. terrae IFP 2001 after induction by cultivation on ETBE.

  8. Short and stereoselective total synthesis of furano lignans (+/-)-dihydrosesamin, (+/-)-lariciresinol dimethyl ether, (+/-)-acuminatin methyl ether, (+/-)-sanshodiol methyl ether, (+/-)-lariciresinol, (+/-)-acuminatin, and (+/-)-lariciresinol monomethyl ether and furofuran lignans (+/-)-sesamin, (+/-)-eudesmin, (+/-)-piperitol methyl ether, (+/-)-pinoresinol, (+/-)-piperitol, and (+/-)-pinoresinol monomethyl ether by radical cyclization of epoxides using a transition-metal radical source.

    Science.gov (United States)

    Roy, Subhas Chandra; Rana, Kalyan Kumar; Guin, Chandrani

    2002-05-17

    Intramolecular radical cyclization of suitably substituted epoxy ethers 4a-g using bis(cyclopentadienyl)titanium(III) chloride as the radical source resulted in trisubstituted tetrahydrofurano lignans and 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans depending on the reaction conditions. The titanium(III) species was prepared in situ from commercially available titanocene dichloride and activated zinc dust in THF. Upon radical cyclization followed by acidic workup, epoxy olefinic ethers 4a-g afforded furano lignans dihydrosesamin 1a, lariciresinol dimethyl ether 1b, acuminatin methyl ether 1e, and sanshodiol methyl ether 1g directly and lariciresinol 1h, acuminatin 1i, and lariciresinol monomethyl ether 1j after removal of the benzyl protecting group by controlled hydrogenolysis of the corresponding cyclized products. The furofuran lignans sesamin 2a, eudesmin 2b, and piperitol methyl ether 2e were also prepared directly by using the same precursors 4a-f on radical cyclization followed by treatment with iodine and pinoresinol 2h, piperitol 2i, and pinoresinol monomethyl ether 2j after controlled hydrogenolysis of the benzyl protecting group of the corresponding cyclized products. Two naturally occurring acyclic lignans, secoisolariciresinol 5h and secoisolariciresinol dimethyl ether 5b, have also been prepared by exhaustive hydrogenolysis of 2h and 2b, respectively.

  9. Biodegradation of the gasoline oxygenates methyl tert-butyl ether, ethyl tert-butyl ether, and tert-amyl methyl ether by propane-oxidizing bacteria.

    Science.gov (United States)

    Steffan, R J; McClay, K; Vainberg, S; Condee, C W; Zhang, D

    1997-11-01

    Several propane-oxidizing bacteria were tested for their ability to degrade gasoline oxygenates, including methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). Both a laboratory strain and natural isolates were able to degrade each compound after growth on propane. When propane-grown strain ENV425 was incubated with 20 mg of uniformly labeled [14C]MTBE per liter, the strain converted > 60% of the added MTBE to 14CO2 in production of nearly stoichiometric amounts of tert-butyl alcohol (TBA), while the initial oxidation of TAME resulted in the production of tert-amyl alcohol. The methoxy methyl group of MTBE was oxidized to formaldehyde and ultimately to CO2. TBA was further oxidized to 2-methyl-2-hydroxy-1-propanol and then 2-hydroxy isobutyric acid; however, neither of these degradation products was an effective growth substrate for the propane oxidizers. Analysis of cell extracts of ENV425 and experiments with enzyme inhibitors implicated a soluble P-450 enzyme in the oxidation of both MTBE and TBA. MTBE was oxidized to TBA by camphor-grown Pseudomonas putida CAM, which produces the well-characterized P-450cam, but not by Rhodococcus rhodochrous 116, which produces two P-450 enzymes. Rates of MTBE degradation by propane-oxidizing strains ranged from 3.9 to 9.2 nmol/min/mg of cell protein at 28 degrees C, whereas TBA was oxidized at a rate of only 1.8 to 2.4 nmol/min/mg of cell protein at the same temperature.

  10. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  11. 1-Chloromethyl-3-nitrobenzene

    Directory of Open Access Journals (Sweden)

    Islam Ullah Khan

    2010-03-01

    Full Text Available In the title molecule, C7H6ClNO2, the plane of the nitro group and the direction of the chloromethyl group are twisted away from the benzene ring, forming dihedral angles of 8.2 (3 and 67.55 (12°, respectively. In the crystal structure, weak intermolecular C—H...O interactions link the molecules into corrugated sheets parallel to the bc plane.

  12. Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

    Science.gov (United States)

    Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

    2017-06-15

    Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m(3)). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary.

  13. Searching for trans ethyl methyl ether in Orion KL(.)

    Science.gov (United States)

    Tercero, B; Cernicharo, J; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J-C

    2015-10-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 10(15) cm(-2) and ≤(1.0 ± 0.2)× 10(15) cm(-2) for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion.

  14. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities.

    Science.gov (United States)

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17μg/mL and 74.62μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.

  15. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities

    Directory of Open Access Journals (Sweden)

    Jingfeng Lou

    2016-03-01

    Full Text Available Abstract One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 µg/mL and median inhibitory concentration (IC50 values ranging from 16.00 to 38.27 µg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 µg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 µg/mL and 74.62 µg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.

  16. Searching for trans ethyl methyl ether in Orion KL⋆

    Science.gov (United States)

    Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

    2015-10-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm-2 and ≤(1.0 ± 0.2) × 1015 cm-2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work was also based on observations carried out with the IRAM 30-m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Appendix A is available in electronic form at http://www.aanda.org

  17. Biodegradation of methyl tert-butyl ether by Kocuria sp.

    Directory of Open Access Journals (Sweden)

    Kiković Dragan D.

    2012-01-01

    Full Text Available Methyl tert-butyl ether (MTBE has been used to replace the toxic compounds from gasoline and to reduce emission of air pollutants. Due to its intensive use, MTBE has become one of the most important environment pollutants. The aim of this paper is isolation and identification of the bacteria from wastewater sample of “HIP Petrohemija” Pančevo (Serbia, capable of MTBE biodegradation. The results of the investigation showed that only the bacterial isolate 27/1 was capable of growth on MTBE. The result of sequence analyzes of 16S rDNA showed that this bacterial isolate belongs to the Kocuria sp. After the incubation period of 86 days, the degradation rates of initial MTBE concentration of 25 and 125 μg/ml were 55 and 36%, respectively. These results indicated that bacteria Kocuria sp. is successfully adapted on MTBE and can be potentially used in bioremediation of soils and waters contaminated with MTBE.

  18. Searching for Trans Ethyl Methyl Ether in Orion KL

    CERN Document Server

    Tercero, B; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J -C

    2015-01-01

    We report on the tentative detection of $trans$ Ethyl Methyl Ether (tEME), $t-CH_3CH_2OCH_3$, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for $gauche$-$trans$-n-propanol, $Gt-n-CH_3CH_2CH_2OH$, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are $\\leq(4.0\\pm0.8)\\times10^{15} cm^{-2}$ and $\\leq(1.0\\pm0.2)\\times10^{15} cm^{-2}$ for tEME and Gt-n-propanol, respectively. The rotational temperature is $\\sim100 K$ for both molecules. We also provide maps of $CH_3OCOH$, $CH_3CH_2OCOH$, $CH_3OCH_3$, $CH_3OH$, a...

  19. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    Science.gov (United States)

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C.

  20. Liquid/air partition coefficients of methyl and ethyl T-butyl ethers, T-amyl methyl ether, and T-butyl alcohol.

    Science.gov (United States)

    Nihlen, A; Lof, A; Johanson, G

    1995-01-01

    Partition coefficients are essential to a description of the uptake and distribution of volatile substances in humans and in the development of physiologically based pharmacokinetic models. Liquid/air partition coefficients (lambda) of three ethers, methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), and t-amyl methyl ether (TAME) were determined in vitro by head space-gas chromatography. These ethers, and especially MTBE, are used in unleaded gasoline to enhance the oxygen and octane content, and to reduce the output of carbon monoxide during combustion. Partition coefficients of t-butyl alcohol (TBA), a metabolite of MTBE, were determined also. The liquids tested were fresh human blood, water (physiological saline), and olive oil. The (lambda)blood/air values were: 17.7 (95% confidence interval 17.0-18.4) for MTBE; 11.7 (11.3-12.1) for ETBE; and 17.9 (17.3-18.5) for TAME. Corresponding (lambda)water/air values were 15.2 (14.9-15.5), 8.39 (8.19-8.59), and 11.9 (11.7-12.1). The ethers have a higher affinity for oil, the values for (lambda)oil/air being 120 (114-125), 190 (183-197), and 337 (320-354), respectively. As expected, the (lambda)blood/air and (lambda)water/air for TBA were much higher than for the ethers, 462 (440-484) and 603 (590-617), respectively. The (lambda)oil/air was 168 (161-174) for TBA. The interindividual variability of the (lambda)blood/air (10 subjects) was calculated as the coefficient of variation, and estimated as: 14% for MTBE, 20% for ETBE, 20% for TAME, and 30% for TBA. No significant difference was seen in the (lambda)blood/air between the sexes.

  1. Human gallbladder morphology after gallstone dissolution with methyl tert-butyl ether.

    Science.gov (United States)

    vanSonnenberg, E; Zakko, S; Hofmann, A F; D'Agostino, H B; Jinich, H; Hoyt, D B; Miyai, K; Ramsby, G; Moossa, A R

    1991-06-01

    The effects of methyl tert-butyl ether exposure on the human gallbladder in five patients who were treated for gallstones by contact dissolution is described. Two patients underwent cholecystectomy within 1 week of methyl tert-butyl ether treatment, one patient 2 weeks after, another 10 weeks after, and one 12 weeks after. Indications for cholecystectomy were bilirubinate stones (resistant to methyl tert-butyl ether), catheter dislodgement, bile leakage, and gallstone recurrence (2 patients). Gallstones were dissolved completely in three patients, there was approximately 50% stone reduction in one patient, and no dissolution occurred in the fifth patient. Each gallbladder was examined grossly and histologically. Electron microscopic evaluation was performed in one cases. Typical inflammatory findings of chronic cholecystitis were observed in each gallbladder and were most conspicuous in the submucosa; the mucosal and serosal surfaces were intact. Mild acute inflammatory changes were noted in the submucosa in the two patients with the shortest interval between methyl tert-butyl ether administration and cholecystectomy. There were no ulcerations in the mucosa and no unusual wall thickening or fibrosis in any patient. These observations support the safety of methyl tert-butyl ether perfusion in the human gallbladder; the mild acute changes may be a transient and reversible phenomenon.

  2. Miconidin and miconidin methyl ether from Primula obconica Hance: new allergens in an old sensitizer

    DEFF Research Database (Denmark)

    Paulsen, Evy; Christensen, Lars P; Andersen, Klaus Ejner

    2006-01-01

    Several chemical and clinical observations have suggested the presence of at least one more allergen in addition to primin in Primula obconica. The aim of this study was to investigate the allergenicity of the primin precursor miconidin and the related miconidin methyl ether, both isolated from P...... of the individual primin reactions, and remained inexplicably negative while testing with miconidin in 96% ethanol and pet., while miconidin methyl ether elicited 7 positive reactions. Although both miconidin and miconidin methyl ether may be allergenic only due to their conversion to primin in the skin......, the presence of these substances nevertheless has to be taken into account when assessing the allergenicity of new P. obconica cultivars....

  3. APPLICATION OF PHOTOCATALYTIC PROCESS FOR REMOVAL OF METHYL TERT-BUTYL ETHER FROM HIGHLYCONTAMINATED WATER

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    A. Mesdaghinia

    2007-09-01

    Full Text Available The oxygenate methyl tert-butyl ether is added to gasoline to increase the octane level and to reduce carbon monoxide and hydrocarbon emissions by vehicles. The high mobility, water solubility, and resistance to natural attenuation associated with methyl tert-butyl ether may result in contamination of ground and surface waters. In this research the degradation of aqueous methyl tert-butyl ether at relatively high concentrations was investigated by UV-vis/TiO2/H2O2 photocatalytic process. The effect of important operational parameters such as pH, amount of H2O2, catalyst loading, and irradiation time were also studied. Concentrations of methyl tert-butyl ether and intermediates such as tert-butyl formate and tert-butyl alcohol were measured over a 180 min period using a gas chromatograph equipped with flame ionization detector and combined with headspace sampler. Results showed that the time required for complete degradation increased from 30 to 180min, when the initial concentration was increased from 10 to 500mg/L. The first order rate constant for degradation of methyl tert-butyl ether from the hydroxyl radical was estimated to be 0.177 to 0.022 1/min as the concentration increased from 10 to 500mg/L. Study on the overall mineralization monitored by total organic carbon (TOC analysis showed that in the initial concentration of 100mg/L methyl tert-butyl ether, complete mineralization was obtained after 110min under UV-vis/TiO2/H2O2 photocatalytic process.

  4. Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...

  5. ETBE (ethyl tert butyl ether) and TAME (tert amyl methyl ether) affect microbial community structure and function in soils.

    Science.gov (United States)

    Bartling, Johanna; Esperschütz, Jürgen; Wilke, Berndt-Michael; Schloter, Michael

    2011-03-15

    Ethyl tert butyl ether (ETBE) and tert amyl methyl ether (TAME) are oxygenates used in gasoline in order to reduce emissions from vehicles. The present study investigated their impact on a soil microflora that never was exposed to any contamination before. Therefore, soil was artificially contaminated and incubated over 6 weeks. Substrate induced respiration (SIR) measurements and phospholipid fatty acid (PLFA) analysis indicated shifts in both, microbial function and structure during incubation. The results showed an activation of microbial respiration in the presence of ETBE and TAME, suggesting biodegradation by the microflora. Furthermore, PLFA concentrations decreased in the presence of ETBE and TAME and Gram-positive bacteria became more dominant in the microbial community.

  6. PHOTOCATALYTIC OXIDATION OF METHYL-TERT-BUTYL ETHER FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    The photo-oxidation of methyl tert-butyl ether (MTBE) in water was investigated to determine the feasibility of using photocatalysis for the treatment of MTBE-contaminated drinking water. The feasibility assessment was conducted using slurries of titanium dioxide in both a photo-...

  7. Enhanced diisobutene production in the presence of methyl tertiary butyl ether

    Science.gov (United States)

    Smith, L.A. Jr.

    1983-03-01

    In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

  8. TREATMENT OF METHYL TERT-BUTYL ETHER CONTAMINATED WATER USING PHOTOCATALYSIS

    Science.gov (United States)

    The feasibility of photo-oxidation treatment of methyl tert-butyl ether (MTBE) in water was investigated in three ways, 1) using a slurry falling film photo-reactor, 2) a batch solar reactor system, and 3) a combination of air-stripping and gas phase photooxidation system. MTBE-c...

  9. Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine.

    Science.gov (United States)

    Rastkari, Noushin; Ahmadkhaniha, Reza; Yunesian, Masud

    2009-05-15

    Carbon nanotubes (CNTs) are a kind of new carbon-based nano-materials which have drawn great attention in many application fields. The potential single-walled carbon nanotubes (SWCNTs) as solid-phase microextraction (SPME) adsorbents for the preconcentration of environmental pollutants have been investigated in recent years. The goal of this work was to investigate the feasibility of SWCNTs used as adsorbents for solid-phase microextraction of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) in human urine. SWCNTs were attached onto a stainless steel wire through organic binder. Potential factors affecting the extraction efficiency were optimized, including extraction time, extraction temperature, desorption time, desorption temperature, and salinity. The developed method showed good performance according to the ICH performance criteria for bioanalytical methods. The calibration curves of the ethers were linear (r(2)>or=0.992) in the range from 10 to 5000 ng L(-1). The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng L(-1) for all the analytes. In addition, compared with the commercial carboxen/polydimethylsiloxane (CAR/PDMS) fiber, the SWCNT fiber showed better thermal stability (over 350 degrees C) and longer life span (over 150 times). The developed method was applied successfully to determine trace level of the ethers in urine of 10 healthy male volunteers.

  10. Synthesis and Characterisation of Bis-(chloromethyl Oxetane, its Homopolymer and Copolymer with Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    T. S. Reddy

    2006-07-01

    Full Text Available Bis-(chloromethyl oxetane (BCMO was synthesised from pentaerythritol by chlorination,followed by ring closure. It was polymerised using BF3-etherate and butanediol system, similarlythe BCMO–THF (tetrahydrofuran copolymer was also synthesised. The monomers and thepolymers were characterised by IR, 1H-NMR and molecular weight. Flame retardant propertiesof the poly-BCMO were also investigated.

  11. Synthesis and Properties of Anion Exchangers Derived from Chloromethyl Styrene Codivinylbenzene and Their Use in Water Treatment

    Directory of Open Access Journals (Sweden)

    Hesham A. Ezzeldin

    2010-01-01

    Full Text Available Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characterized by a variety of techniques such as analytical titrations, nitrogen analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads.

  12. Separation of the Ternary System of Methanol/Methyl Butyl Ether/1-Butylchloride

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The separation of ternary methanol/methyl butyl ether/1-butylchloride mixtures was investigated, which are the main components of the waste liquid. After preliminary studies on the ternary system, the integrated process of extraction and distillation was put forward to separate the ternary system. The results show that methanol can be removed from the mixtures by extraction using water as the extracting agent. Through distillation of extract and dried raffinate respectively, methanol,methyl butyl ether and 1-butylchloride can be separated and recovered. In addition, the optimal volume for the extracting agent and effects of reflux ratio on the yield of product were also studied. The optimal volume ratio of the extracting agent to material is 1: 3.5, and the yield of the product increases with the increase of reflux ratio.

  13. Transesterification of propylene glycol methyl ether in chromatographic reactors using anion exchange resin as a catalyst.

    Science.gov (United States)

    Oh, Jungmin; Sreedhar, Balamurali; Donaldson, Megan E; Frank, Timothy C; Schultz, Alfred K; Bommarius, Andreas S; Kawajiri, Yoshiaki

    2016-09-30

    Reactive chromatography using an anion exchange resin is proposed for a transesterification reaction of propylene glycol methyl ether (DOWANOL™ PM) with ethyl acetate to produce propylene glycol methyl ether acetate (DOWANOL™ PMA). This reaction is studied in batch and chromatographic reactors catalyzed by an anion exchange resin. Several anion exchange resins are tested and compared based on the performance of resin as an adsorbent and a catalyst. A chromatographic column is packed with a selected catalyst, AMBERLITE™ IRA904, and both reaction and chromatographic elution are studied at different temperatures and feed concentrations. The resulting chromatograms are fitted to a mathematical model to obtain adsorption equilibrium and reaction kinetic parameters by the inverse method. Compared to esterification investigated in a previous study, transesterification has advantages such as a higher conversion at lower temperature and easy removal of the byproduct which may lead to higher productivity. Deactivation of anion exchange resins is observed and potential solutions are suggested.

  14. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry.

    Science.gov (United States)

    Scibetta, Licia; Campo, Laura; Mercadante, Rosa; Foà, Vito; Fustinoni, Silvia

    2007-01-02

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L(-1), within- and between-run precision, as coefficient of variation, ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L(-1)), ETBE (<6 ng L(-1)), and TAME (<6 ng L(-1)) were obtained.

  15. Trans-ethyl methyl ether in space - A new look at a complex molecule in selected hot core regions

    CERN Document Server

    Fuchs, G W; Giesen, T F; Wyrowski, F

    2005-01-01

    An extensive search for the complex molecule trans-ethyl methyl ether towards several hot core regions has been performed. Using the IRAM 30m telescope and the SEST 15m we looked at several frequencies where trans-ethyl methyl ether has strong transitions, as well as lines which are particularly sensitive to the physical conditions in which the molecule can be found. We included G34.26, NGC6334(I), Orion KL, and W51e2 which have previously been proven to have a rich chemistry of complex molecules. Our observations cannot confirm the tentative Orion KL detection made by Charnley et al. (2001) within their stated column density limits, but we confirm the existence of the trans-ethyl methyl ether towards W51e2 with a column density of 2x10^14 cm-2. The dimethyl ether/methanol ratio of 0.6 as well as the newly found ethyl methyl ether/ethanol ratio of 0.13 indicate relative high abundances of ethers toward W51e2. Furthermore, the observation of ethyl methyl ether also confirms the importance of ethanol as a grain...

  16. Geissoschizine methyl ether N-oxide, a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla.

    Science.gov (United States)

    Jiang, Wei-Wei; Su, Jia; Wu, Xing-De; He, Juan; Peng, Li-Yan; Cheng, Xiao; Zhao, Qin-Shi

    2015-01-01

    Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.

  17. CHLOROMETHYLATION OF POLYMERS MADE FROM TECHNICAL DIVINYLBENZENE AND PROPERTY OF THE CHLOROMETHYLATED POLYMERS

    Institute of Scientific and Technical Information of China (English)

    SHI Rongfu; XU Mancai; SHI Zuoqing; WANG Chunhong; FAN Yunge; FENG Junqian; HE Binglin

    2001-01-01

    The goal of this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents. For this study, the factors that effect the chloromethylation reaction, such as the pore structure of the polymer, the ratio of the reactants to catalyst, the reaction temperature and reaction time and so on were investigated, and the pore structure and property of the chloromethylated polymers were studied The results showed that polymers of technical divinylbenzene could be chloromethylated successfully, and the adsorptive property of the chloromethylated resin was different from that of the initial resin.

  18. Methanol and 2-methyl-1-propanol (isobutanol) coupling to ethers and dehydration over Nafion H: Selectivity, kinetics, and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Nunan, J.G.; Klier, K.; Herman, R.G. (Lehigh Univ., Bethlehem, PA (United States))

    1993-02-01

    The dehydration of a mixture of methanol and isobutanol has been studied over the sulfonic acid Nafion H catalyst. Dehydration products consisted of dimethyl ether (DME), di-isobutyl ether (DIBE), methyl-isobutyl ether (MIBE), butenes, octenes, and traces of methyl-tertiarybutyl ether (MTBE). At low temperatures and high alcohol pressures (P [ge] 150 kPa), the dehydration product slate was dominated by ether formation with selectivity within the ethers significantly in favor of the mixed ether, MIBE. The rates of ether and butene formation as a function of alcohol pressure could be described by Langmuir-Hinshelwood kinetics in which competitive adsorption of the two alcohols on the surface -SO[sub 3]H sites was the dominant feature. The kinetics of isobutanol dehydration to isobutene were consistent with a dual-site mechanism involving the cooperative action of a free surface -SO[sub 3]H site and an adjacent adsorbed alcohol molecule. Dehydration to ethers was consistent with the reaction of two adsorbed alcohols, also by a dual-site mechanism. As a consequence, dehydration to symmetric ethers showed saturation-type kinetics as a function of alcohol pressure, while the rate of isobutene formation went through a distinct maximum. Due to the competitive adsorption of methanol and isobutanol, the mixed ether MIBE was formed at a maximum rate with an optimum ratio of partial pressures of the two alcohols. The high selectivity to MIBE was explained by stronger adsorption of isobutanol on the catalyst surface as compared to methanol. The absence of MTBE and the predominance of products such as MIBE and 2,5-dimethylhexene suggests that dehydration to give free carbenium ions that subsequently rearrange to the more stable tertiary intermediate was not occurring. It was proposed that the alcohols react with the -SO[sub 3]H groups to give oxonium ions or esters. These intermediates couple to give the product ethers or octenes. 24 refs., 13 figs., 1 tab.

  19. Metabolism of methyl tert-butyl ether and other gasoline ethers in mouse liver microsomes lacking cytochrome P450 2E1.

    Science.gov (United States)

    Hong, J Y; Wang, Y Y; Bondoc, F Y; Yang, C S; Gonzalez, F J; Pan, Z; Cokonis, C D; Hu, W Y; Bao, Z

    1999-03-08

    To reduce the production of pollutants in motor vehicle exhaust, methyl tert-butyl ether (MTBE) and other ethers such as ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are added to gasoline as oxygenates for more complete combustion. Metabolism of these gasoline ethers is catalyzed by cytochrome P450 (P450) enzymes. P450 2E1, which metabolizes diethyl ether, was suggested to be an enzyme involved. The present study used 2E1 knock-out mice (2E1-/-) to assess the contribution of 2E1 to the metabolism of MTBE, ETBE and TAME. Liver microsomes prepared from the 2E1 knock-out mice lacked 2E1 activity (assayed as N-nitrosodimethylamine demethylation), but were still active in metabolizing all three gasoline ethers. The levels of ether-metabolizing activity (nmol/min per mg) in the liver microsomes from 7 week old female 2E1 knock-out mice were 0.54+/-0.17 for MTBE, 0.51+/-0.24 for ETBE and 1.14+/-0.25 for TAME at a 1 mM substrate concentration. These activity levels were not significantly different from those of the sex- and age-matched C57BL/6N and 129/Sv mice, which are the parental lineage strains of the 2E1 knock-out mice and are both 2E1+/+. Our results clearly demonstrate that 2E1 plays a negligible role in the metabolism of MTBE, ETBE and TAME in mouse livers.

  20. Experimental Analysis and Energetic Evaluation for Mahua Oil Methyl Ester with Diethyl Ether

    Directory of Open Access Journals (Sweden)

    Bhanu Pratap SINGH

    2014-11-01

    Full Text Available A theoretical method based on various existing process models has been developed for the performance evaluation of a compression ignition engine by using diesel and Mahua oil as an input fuel. Experimental evaluations of Mahua oil methyl ester/diesel along with diethyl ether were tested on a single cylinder naturally-aspirated indirect-injection diesel engine. The purpose of using diethyl ether with diesel/biodiesel is to control the emission from the diesel engine and to improve its performance. The effect of test fuels at different volumetric proportion and loads are also analyzed on the engine performance and emission. The comparisons of theoretical and experimental results are discussed. Engine performance characteristics predicted by this model are in closer approximation to that of experimental results. Engineering equation solver has been used to validate the model with the experimental results.

  1. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, Licia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Campo, Laura [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Mercadante, Rosa [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Foa, Vito [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Fustinoni, Silvia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy)]. E-mail: silvia.fustinoni@unimi.it

    2007-01-02

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L{sup -1}, within- and between-run precision, as coefficient of variation, <22 and <16%, accuracy within 20% the theoretical level, and limit of detection of 6 ng L{sup -1} for all the analytes. The influence of the matrix on the quantification of these ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L{sup -1}), ETBE (<6 ng L{sup -1}), and TAME (<6 ng L{sup -1}) were obtained.

  2. Photo catalytic degradation of methyl tert-Butyl Ether (MTBE) from contaminated water: complete mineralization

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, A.; Nasseri, S.; Maleki, A.; Aghvami, T.

    2009-07-01

    Methyl tert-butyl ether (MTBE) has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may result in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO{sub 2}/O{sub 2} photo catalytic process. The effect of important operational parameters such as ph, oxygen flow, catalyst loading, and irradiation time were also studied. (Author)

  3. Influence of Temperature on Thermodynamic Properties of Methyl t-Butyl Ether (MTBE) + Gasoline Additives

    Science.gov (United States)

    Gonzalez-Olmos, R.; Iglesias, M.; Goenaga, J. M.; Resa, J. M.

    2007-08-01

    The densities and sound speeds of binary mixtures of methyl tert-butyl ether (MTBE) + (benzene, toluene, ethylbenzene, isooctane, tert-butyl alcohol) have been measured at temperatures from 288.15 to 323.15 K and at atmospheric pressure over the complete concentration range. The experimental excess volumes and deviations of isentropic compressibility were calculated. The deviation of isentropic compressibility data have been analyzed in terms of different theoretical models; adequate agreement between the experimental and predicted values is obtained. The data from this study improve the data situation related to gasoline additives and help to understand the MTBE volumetric and acoustic behavior for various chemical systems.

  4. New corrosion inhibitor acrylamide methyl ether for mild steel in 1 M HCl

    Science.gov (United States)

    Ma, Xinyu; Jiang, Xiaohui; Xia, Shuwei; Shan, Mingli; Li, Xia; Yu, Liangmin; Tang, Qunwei

    2016-05-01

    Pursuit of good inhibition performance has been a persistent objective for advanced inhibitor industry. Here we demonstrate the experimental realization of a new corrosion inhibitor acrylamide methyl ether (AAME) from N-Methylol acrylamide (N-MAM) for mild steel in 1 M HCl. The resultant adsorption films have inhibition efficiency as high as 96.2%. Moreover, a theoretical investigation is also launched to demonstrate the potential mechanism behind the promising corrosion behaviors. This work represents a significant step forward, as it demonstrates how to make scalable AAME inhibitors as well as to enhance inhibition performances for high-efficiency and cost-effective corrosion inhibition platforms.

  5. Evaluation of Methyl Fluoride and Dimethyl Ether as Inhibitors of Aerobic Methane Oxidation

    OpenAIRE

    Oremland, Ronald S.; Culbertson, Charles W.

    1992-01-01

    Methyl fluoride (MF) and dimethyl ether (DME) were effective inhibitors of aerobic methanotrophy in a variety of soils. MF and DME blocked consumption of CH4 as well as the oxidation of 14CH4 to 14CO2, but neither MF nor DME affected the oxidation of [14C]methanol or [14C]formate to 14CO2. Cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by MF. Nitrification (ammonia oxidation) in soils was inhibited by both MF and DME. Production of N2O via nitrification was in...

  6. Method for determination of methyl tert-butyl ether in gasoline by gas chromatography.

    Science.gov (United States)

    Achten, C; Püttmann, W

    2001-03-02

    A simple method for the determination of methyl tert-butyl ether (MTBE) in gasoline has been developed. The separation of MTBE from other analytes was controlled by the use of gas chromatography-mass spectrometry in the full scan mode using the characteristic primary, secondary and tertiary ions m/z 73, 57 and 43. The sample mass spectrum did not show any superimposition of other analytes. The separation from the common gasoline component 2-methylpentane was sufficient for reliable quantitation. An application of the developed conditions using gas chromatography with flame ionization detection was performed by the analysis of regular, euro super, super premium unleaded and 'Optimax' gasoline from petrol stations in the area of Frankfurt/Main, Germany. Regular unleaded gasoline shows an average MTBE content of 0.4% (w/w), whereas the MTBE content in euro super gasoline varies between 0.4 and 4.2% (w/w). The blending of MTBE to super premium has increased from 8.2% (w/w) in 1998 to 9.8% (w/w) on average in 1999. The recently introduced gasoline 'Optimax' shows an average MTBE content of 11.9% (w/w). The presented method might also be used for the analysis of other ethers, such as ethyl tert-butyl ether, which requires the use of another internal standard.

  7. Chloromethylation of asphyalthene concentrates of petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Pokonova, Yu.V.; Proskuryakov, V.A.; Ashirov, A.; Mitrofanova, L.M.

    1980-01-01

    It was shown that chloromethylation of asphalthene concentrates is an extremely rapid reaction with a low energy barrier; polychloromethyl derivatives contain 16 to 30% chlorine. The activity of Friedel-Krafts catalysts in chloromethylation and the competing reaction of condensation of chloromethyl derivatives decreases in the order FeCl/sub 3/ > ZnCl/sub 2/ > SnCl/sub 2/ > SnCl/sub 4/ > AlCl/sub 3/ > TiCl/sub 3/ > TiCl/sub 4/ > SbCl/sub 3/ > SbCl/sub 5/. Strong and weak basic anion-exchange resins (powdered) were obtained by amination of chloromethylated products, these resins having a considerable rate of ion-exchange, high dynamic, kinetic characteristics and high radiation resistance. 2 figures, 2 tables.

  8. Gall stone dissolution with methyl tert-butyl ether: how to avoid complications.

    Science.gov (United States)

    Hellstern, A; Leuschner, M; Frenk, H; Dillinger, H W; Caspary, W; Leuschner, U

    1990-01-01

    Fifty of 52 patients with cholesterol gall bladder stones were treated with methyl tert-butyl ether. In 48 of 50 (96%) patients the stones dissolved after an average interval of 9.5 hours. Mean stone size was 1.7 cm (0.5-3.3 cm), mean stone number was 14.6 (1-70). Twelve patients (24%) complained of nausea, a burning sensation, or vomiting. In one patient bile leakage occurred and another suffered haematobilia (4%). The puncture set was improved, and a special basket was developed to extract stones that had escaped into the cystic duct. To prevent bile leakage or haemorrhage from the incision channel, a tissue adhesive was injected into the channel or ceruletid was administered subcutaneously before removing the catheter to induce contraction of the gall bladder. Thus we were able to treat 44 patients without any complications. Nausea and vomiting could be reduced if the treatment time was kept short and the perfusion volume was as low as possible. Methyl tert-butyl ether treatment is a successful treatment of gall bladder stones with few complications. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2387519

  9. Synthesis of (2-amino)ethyl derivatives of quercetin 3-O-methyl ether and their antioxidant and neuroprotective effects.

    Science.gov (United States)

    Lee, Young Hun; Kim, Hyoung Ja; Yoo, Ho; Jung, Seo Yun; Kwon, Bong Jin; Kim, Nam-Jung; Jin, Changbae; Lee, Yong Sup

    2015-08-01

    Reactive oxygen species have been implicated in several diseases, particularly in ischemia-reperfusion injury. Quercetin 3-O-methyl ether has been reported to show potent antioxidant and neuroprotective activity against neuronal damage induced by reactive oxygen species. Several aminoethyl-substituted derivatives of quercetin 3-O-methyl ether have been synthesized to increase water solubility while retaining antioxidant and neuroprotective activity. Among such derivatives, compound 3a shows potent and well-balanced antioxidant activity in three types of cell-free assay systems and has in vivo neuroprotective effects on transient focal ischemic injury induced by the occlusion of the middle cerebral artery in rats.

  10. Experimental Analysis of Performance of Diesel Engine Using Kusum Methyl Ester With Diethyl Ether as Additive

    Directory of Open Access Journals (Sweden)

    Sandip S. Jawre,

    2014-05-01

    Full Text Available The fossile fuels are widely used in diesel engine and continually depleting with increasing consumption and prices day by day. The fatty acid methyl ester has become an effective alternative to diesel. Various types of vegetable oil such as Jatropha, karanja, cottonseed, neem, sunflower, palm, mahuva, coconut etc. can be used as fuel in diesel engine. Kusum oil is one of the fuel used in present work. The viscosity of kusum oil is very high, so it was reduced by Transesterification process. This study presents effect of diethyl ether as additive to biodiesel of kusum (schliechera oleosa methyl ester on the performance and emission of diesel engine at different load and constant speed and two different injection pressure (170 and 190 bar. From literature it was observed that very few studies had been conducted on use of neat biodiesel and diethyl ether blends and use of kusum methyl ester (KME in diesel engine found to be very less as compared to different biodiesel. Hence this topic was taken under study. The fuels and its blends used are 100% diesel, B100 (100% KME, BD-1 (95% KME, 5% DEE, BD-2 (90% KME, 10% DEE, BD-3 (85% KME, 15% DEE respectively. It was observed that the performance of engine increases at high injection pres-sure. The results indicate that lower BSFC was observed with BD-3 as compared to B100, BD-1 and BD-2. Brake thermal efficiency of BD-3 decreased at 170 bar injection pressure but it increase at 190 bar. Drastic re-duction in smoke is observed with all blends at higher engine loads. DEE addition to biodiesel reflects better engine performance compared to neat biodiesel.

  11. SYNTHESIS OF METHYL TERT-BUTYL ETHER CATALYZED BY ACIDIC ION-EXCHANGE RESINS - INFLUENCE OF THE PROTON ACTIVITY

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1995-01-01

    The catalytic activity of various strong acid ion-exchange resins on the synthesis of methyl tert-butyl ether (MtBE) from methanol and isobutene has been investigated. Relative to Amberlyst 15, Kastel CS 381 and Amberlyst CSP have similar rate constants, whereas Duolite ES 276 and Amberlyst XE 307 h

  12. TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

    Science.gov (United States)

    Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

  13. INTERACTION OF METHYL-TERT BUTYL ETHER AND WATER STRESS ON SEED GERMINATION AND SEEDLING GROWTH IN SOIL MICROCOSMS

    Science.gov (United States)

    Methyl tert-butyl ether (MTBE) is a widespread contaminant in surface and ground water in the United States. Frequently irrigation is used to water fields to germinate planted seeds and sustain plant growth. A likely possibility exists that water used may have some MTBE. Our s...

  14. Studies on the Fluorescence Properties of Chloromethyl Polystyrene Supported Fluorophore

    Institute of Scientific and Technical Information of China (English)

    REN HongXia; LEI ZiQiang; WANG SongBai; YANG ZhiWang; WANG YunPu

    2001-01-01

    @@ The basic materials used in making photoluminescence materials are all synthesized polymers at present, such as PVC, etc [1]. Red and green LEDs are easy to be prepared, but the blue LED is difficult to be done. In this paper, we used chloromethyl polystyrene as supporter, leading into the known fluorophore by polymer chemical reaction, so as to obtaining blue luminous material. The PS-CH2Cl supported fluorophore are prepared by PS-CH2Cl and benzidine (B), dimethylbenzidine (MA), 4,4'-diamino-diphenyl ether (DAPE), 4,4'-diamino-diphenyl sulfone (DAPS), respectively. They were characterized by IR and elemental analysis. The stead state fluorescence properties of these supported polymers were investigated.The results were summarized in table 1.

  15. Studies on the Fluorescence Properties of Chloromethyl Polystyrene Supported Fluorophore

    Institute of Scientific and Technical Information of China (English)

    REN; HongXia

    2001-01-01

    The basic materials used in making photoluminescence materials are all synthesized polymers at present, such as PVC, etc [1]. Red and green LEDs are easy to be prepared, but the blue LED is difficult to be done. In this paper, we used chloromethyl polystyrene as supporter, leading into the known fluorophore by polymer chemical reaction, so as to obtaining blue luminous material.  The PS-CH2Cl supported fluorophore are prepared by PS-CH2Cl and benzidine (B), dimethylbenzidine (MA), 4,4'-diamino-diphenyl ether (DAPE), 4,4'-diamino-diphenyl sulfone (DAPS), respectively. They were characterized by IR and elemental analysis. The stead state fluorescence properties of these supported polymers were investigated.The results were summarized in table 1.  ……

  16. Sphaeropsidones, phytotoxic dimedone methyl ethers produced by Diplodia cupressi: a structure-activity relationship study.

    Science.gov (United States)

    Evidente, Antonio; Maddau, Lucia; Scanu, Bruno; Andolfi, Anna; Masi, Marco; Motta, Andrea; Tuzi, Angela

    2011-04-25

    Sphaeropsidone and episphaeropsidone are two phytotoxic dimedone methyl ethers produced by Diplodia cupressi, the causal agent of a canker disease of cypress in the Mediterranean area. In this study, eight derivatives obtained by chemical modifications and two natural analogues were assayed for phytotoxic and antifungal activities, and a structure-activity relationship was examined. Each compound was tested on nonhost plants and on five fungal pathogenic species belonging to the genus Phytophthora. The results provide insights into structure-activity relationships within these compounds. It was found that the hydroxy group at C-5, the absolute C-5 configuration, the epoxy group, and the C-2 carbonyl group appear to be structural features important in conferring biological activity. The conversion of sphaeropsidone into the corresponding 1,4-dione derivative led to a compound showing greater antifungal activity than its precursor. This finding could be useful in devising new natural fungicides for practical application in agriculture.

  17. Evaluation of methyl fluoride and dimethyl ether as inhibitors of aerobic methane oxidation

    Science.gov (United States)

    Oremland, R.S.; Culbertson, C.W.

    1992-01-01

    Methyl fluoride (MF) and dimethyl ether (DME) were effective inhibitors of aerobic methanotrophy in a variety of soils. MF and DME blocked consumption of CH4 as well as the oxidation of 14CH4 to 14CO2, but neither MF nor DME affected the oxidation of [14C]methanol or [14C]formate to 14CO2. Cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by MF. Nitrification (ammonia oxidation) in soils was inhibited by both MF and DME. Production of N2O via nitrification was inhibited by MF; however, MF did not affect N2O production associated with denitrification. Methanogenesis was partially inhibited by MF but not by DME. Methane oxidation was ~100-fold more sensitive to MF than was methanogenesis, indicating that an optimum concentration could be employed to selectively block methanotrophy. MF inhibited methane oxidation by cell suspensions of Methylococcus capsulatus; however, DME was a much less effective inhibitor.

  18. Isolation and Initial Characterization of A Pure Cultures Capable to Degradation Methyl tert- Butyl Ether (MTBE

    Directory of Open Access Journals (Sweden)

    A Nikpey

    2006-07-01

    Full Text Available Methyl tert-butyl ether (MTBE, a gasoline octane enhancer, was introduced as a substitute for lead tetraethyl over 30 years ago. Widespread use of MTBE in gasoline, has introduced MTBE into the environment compartments, mostly into the under ground and surface water and water as a second most frequently detected contaminant. In this study, we have isolated pure cultures from bacterial consortium capable to use MTBE as a sole carbon and energy source. MTBE biodegradation rate was measured in headspace by gas chromatography. Initial liner rates of biodegradation by Pinpoint and white strains were found 2.9 mg and 3 mg MTBE hˉ1 gˉ1 wet biomass, respectively. The results of 16S rDNA PCR disclosed similarities in the banding patterns between the cultures, and the known degrading strain PM1. The results of this study suggest promising perspectives for engineering the in situ bioremediation of MTBE.

  19. Searching for trans ethyl methyl ether in Orion KL★,★★

    Science.gov (United States)

    Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

    2015-01-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm−2 and ≤(1.0 ± 0.2)× 1015 cm−2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. PMID:26869726

  20. Degradation of aqueous methyl tert-butyl ether by photochemical, biological, and their combined processes

    Directory of Open Access Journals (Sweden)

    Azadeh Asadi

    2006-01-01

    Full Text Available The degradation of aqueous methyl tert-butyl ether (MTBE at relatively high concentrations was investigated by various photo-induced oxidation processes such as UV/H2O2 and UV/TiO2 as well as biological processes and their combination. It was shown that the degradation of MTBE by UV/H2O2 and TiO2 photocatalytic followed a first-order model with apparent rate constant of 1.31×10−1 and 1.21×10−2 min-1, respectively. It was observed that UV/H2O2/TiO2 process did not have any advantages over each of the other processes alone. The biodegradation of methyl tert-butyl ether (MTBE was evaluated using aerobic mixed culture with three different approaches, including ultimate biological oxygen demand (BODU assessment, nonacclimated, and acclimated mixed cultures. The apparent rate constant for the biodegradation of MTBE by nonacclimated mixed culture was 4.36×10−2 day-1. It was shown that the acclimatization of the mixed cultures enhanced the rate of biodegradation of MTBE to 3.24×10−1mg L-1h-1. Finally, the effects of the photocatalytic pretreatment of aqueous MTBE on its subsequent biological treatment were studied. It was observed that the rate of bioreaction was not enhanced and the photocatalytic pretreatment had adverse effects on its biological treatment so that the apparent rate constant decreased to 2.83×10−1 mg L-1h-1.

  1. CCSD(T) study of the far-infrared spectrum of ethyl methyl ether.

    Science.gov (United States)

    Senent, M L; Ruiz, R; Villa, M; Domínguez-Gómez, R

    2009-02-14

    Band positions and intensities for the far-infrared bands of ethyl methyl ether are variationally determined from a three-dimensional (3D) potential energy surface calculated with CCSD(T)/cc-pVTZ theory. For this purpose, the energies of 181 selected geometries computed optimizing 3n-9 parameters are fitted to a 3D Fourier series depending on three torsional coordinates. The zero point vibrational energy correction and the search of a correct definition of the methyl torsional coordinate are taken into consideration for obtaining very accurate frequencies. In addition, second order perturbation theory is applied on the two molecular conformers, trans and cis-gauche, in order to test the validity of the 3D model. Consequently, a new assignment of previous experimental bands, congruent with the new ab initio results, is proposed. For the most stable trans-conformer, the nu(30), nu(29), and nu(28) fundamental transitions, computed at 115.3, 206.5, and 255.2 cm(-1), are correlated with the observed bands at 115.4, 202, and 248 cm(-1). For the cis-gauche the three band positions are computed at 91.0, 192.5, and 243.8 cm(-1). Calculations on the -d(3) isotopomer confirm our assignment. Intensities are determined at room temperature and at 10 K. Structural parameters, potential energy barriers, anharmonic frequencies for the 3n-9 neglected modes, and rotational parameters (rotational and centrifugal distortion constants), are also provided.

  2. DFT study on the adsorption of diethyl, ethyl methyl, and dimethyl ethers on the surface of gallium doped graphene

    Science.gov (United States)

    Shokuhi Rad, Ali; Sani, Emad; Binaeian, Ehsan; Peyravi, Majid; Jahanshahi, Mohsen

    2017-04-01

    In this study, we used density functional theory (DFT) to search on the adsorption properties of three important compounds of ether family; diethyl ether (DEE), ethyl methyl ether (EME), and dimethyl ether (DME) on the surface of Gallium doped graphene (GaG). We used three functionals (B3LYP, wb97xd, and MPW1PW91) for optimization and calculation of adsorption energy. After fully optimization, we scrutinized on the charge allocations on the adsorbed ethers as well as GaG (at the area of interaction) based on natural bond orbitals (NBO). Besides, we have calculated the amount of charge transfer upon adsorption of each analyte. We revel that GaG is an ideal adsorbent for chemisorption of all above-mentioned ethers. There is a little difference between the values of adsorption; -123.5, -120, and -118.3 kJ/mol (based on wb97xd) for DEE, EME, and DME, respectively. We found significant changes in the electronic structure of both adsorbent and adsorbate upon adsorption. Moreover, results of charge analyses confirm GaG is a p-type semiconductor.

  3. SYNTHESIS AND CHARACTERIZATION OF A NEW COMBLIKE POLYMER BASED ON POLY (VINYL METHYL ETHER-ALT-MALEIC ANHYDRIDE) BACKBONE

    Institute of Scientific and Technical Information of China (English)

    DING Liming; LIN Yunqing; ZHOU Zinan; NI Jianlong; CHEN Donglin

    1995-01-01

    A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by IR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by 13C NMR. The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.

  4. A General Synthetic Procedure for 2-chloromethyl-4(3H-quinazolinone Derivatives and Their Utilization in the Preparation of Novel Anticancer Agents with 4-Anilinoquinazoline Scaffolds

    Directory of Open Access Journals (Sweden)

    Ying-Lan Zhao

    2010-12-01

    Full Text Available In our ongoing research on novel anticancer agents with 4-anilinoquinazoline scaffolds, a series of novel 2-chloromethyl-4(3H-quinazolinones were needed as key intermediates. An improved one-step synthesis of 2-chloromethyl-4(3H-quinazolinones utilizing o-anthranilic acids as starting materials was described. Based on it, 2-hydroxy-methyl-4(3H-quinazolinones were conveniently prepared in one pot. Moreover, two novel 4-anilinoquinazoline derivatives substituted with chloromethyl groups at the 2-position were synthesized and showed promising anticancer activity in vitro.

  5. Isobaric vapor-liquid equilibria in the systems methyl 1,1-dimethylethyl ether + hexane and + heptane

    Energy Technology Data Exchange (ETDEWEB)

    Wisniak, J.; Magen, E.; Shachar, M.; Zeroni, I.; Segura, H. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Chemical Engineering; Reich, R. [Univ. de Concepcion (Chile). Dept. of Chemical Engineering

    1997-03-01

    The vapor-liquid equilibrium at 94 kPa has been determined for the binary systems of methyl 1,1-dimethylethyl ether (MTBE) with hexane and with heptane. Both systems deviate slightly from ideal behavior, can be described as regular solutions, and do not present an azeotrope. The activity coefficients and boiling point of the solutions were correlated with its composition by the Redlich-Kister, Wohl, Wilson, UNIQUAC, NRTL, and Wisniak-Tamir equations.

  6. Biological Activity of Methyl tert-butyl Ether in Relation to Soil Microorganisms has a Negative Environmental Impact

    OpenAIRE

    Gholam H.S. Bonjar

    2005-01-01

    Fuel oxygenates are added to gasoline to enhance combustion efficiency of automobiles and reduce air pollution. Methyl tert-butyl ether (MTBE) is the most commonly used oxygenate because of its low cost, high-octane level and ease of blending with gasoline. However, due to its water solubility, high mobility and low biodegradability it leaches in soil subsurface at the speed of groundwater. Amending gasoline with MTBE has made a widespread contamination of groundwater, surface waters in coast...

  7. Biomarkers of exposure to aromatic hydrocarbons and methyl tert-butyl ether in petrol station workers.

    Science.gov (United States)

    De Palma, Giuseppe; Poli, Diana; Manini, Paola; Andreoli, Roberta; Mozzoni, Paola; Apostoli, Pietro; Mutti, Antonio

    2012-06-01

    This cross-sectional study was aimed at reconstructing the exposure to gasoline in 102 petrol station attendants by environmental and biological monitoring of benzene, toluene, ethylbenzene and xylene (BTEX) and biomonitoring of methyl tert-butyl ether (MTBE). Airborne BTEX were higher for manual refuelers than self-service assistants and were highly correlated with each other. Significant relationships were found between airborne BTX and the corresponding urinary solvents (U-BTX) and beween airborne B and urinary MTBE (U-MTBE). Smokers eliminated higher values of U-B, trans,trans-muconic (t,t-MA) and S-phenylmercapturic (S-PMA) acids but not U-MTBE. All these biomarkers were, however, significantly raised during the shift, independently from smoking. Linear regression confirmed that occupational exposure was a main predictor of U-MTBE, U-B and S-PMA values, both the latter confounded by smoking habits. The study supports the usefulness of biomonitoring even at low exposure levels.

  8. Generation Performance of a Fuel Cell Using Hydrogen and Di-methyl-ether (DME) Mixed Gas

    Science.gov (United States)

    Haraguchi, Tadao; Watanabe, Takashi; Yamashita, Masahiro; Tsutsumi, Yasuyuki; Yamashita, Susumu

    Di-methyl-ether (DME), an oxygenated hydrocarbon, can facilitate hydrogen manufacture by steam reforming reaction at low temperature. Methanol and DME steam reforming at 250-300°C, reforming DME into hydrogen, can be performed easily with small-scale and simple equipment. Whether the hydrogen output from the reformer for supply to the fuel cell includes DME, and how this affects the generation performance has yet to be confirmed. The purpose of this paper is to investigate the supply of a fuel cell with mixtures of DME and H2 in varying proportions and to clarify the effect on generation performance. Conclusions are as follows: (1) For a supply of DME and H2 mixed gas, DME is consumed after the H2 is consumed. By comparing the experimental values with theoretical values of consumption of pure H2, a mixture of DME and H2, and pure DME, it proved to be possible to roughly predict the experimental values by calculation. (2) The voltage value moved to near the DME voltage after the H2 was consumed, the current density increased after the H2 was consumed. (3) During continuous running the voltage load was observed to fluctuate.

  9. A QSRR Study on the Relative Retention Time of Halogenated Methyl-phenyl Ethers

    Institute of Scientific and Technical Information of China (English)

    XU Hui-Ying; YU Qing-Sen; ZOU Jian-Wei; WANG Yan-Hua; WANG Hong-Qing; CHEN Xue-Song

    2006-01-01

    Halogenated methyl-phenyl ethers (anisoles) are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G* level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time (RRT) and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials (ESPs) together with the molecular volume (Vmc) could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.

  10. Artificial Neural Network Approach to Predict Biodiesel Production in Supercritical tert-Butyl Methyl Ether

    Directory of Open Access Journals (Sweden)

    Obie Farobie

    2016-05-01

    Full Text Available In this study, for the first time artificial neural network was used to predict biodiesel yield in supercritical tert-butyl methyl ether (MTBE. The experimental data of biodiesel yield conducted by varying four input factors (i.e. temperature, pressure, oil-to-MTBE molar ratio, and reaction time were used to elucidate artificial neural network model in order to predict biodiesel yield. The main goal of this study was to assess how accurately this artificial neural network model to predict biodiesel yield conducted under supercritical MTBE condition. The result shows that artificial neural network is a powerful tool for modeling and predicting biodiesel yield conducted under supercritical MTBE condition that was proven by a high value of coefficient of determination (R of 0.9969, 0.9899, and 0.9658 for training, validation, and testing, respectively. Using this approach, the highest biodiesel yield was determined of 0.93 mol/mol (corresponding to the actual biodiesel yield of 0.94 mol/mol that was achieved at 400 °C, under the reactor pressure of 10 MPa, oil-to-MTBE molar ratio of 1:40 within 15 min of reaction time.

  11. Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-09-01

    Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

  12. Radiation crosslinking and scission of poly(vinyl methyl ether) in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Janik, Ireneusz; Rosiak, Janusz M. E-mail: rosiakjm@mitr.p.lodz.pl

    2002-03-01

    For a wide range of poly(vinyl methyl ether) (PMVE) concentrations (1-16 g dm{sup -3}), in anoxic conditions, polymer-derived radicals recombine in two major pathways: (i) crosslinking and (ii) disproportionation. Both these processes proceed inter- and intramolecularly. The radiation-chemical yields and kinetics of crosslinking have been studied by pulse radiolysis with light scattering intensity detection (LSI). In the absence of oxygen, G-values of intermolecular crosslinking were determined on the basis of LSI changes versus applied dose and compared with the results obtained previously for {gamma}-irradiated samples. It has been found that the first half-life time of intermolecular crosslinking decreases with increasing dose per pulse. Addition of small amounts of macroradical scavenger (cysteamine hydrochloride) decreases, drastically, the increase of LSI signal. On increasing the PVME concentration, intermolecular crosslinking becomes more efficient. In the presence of oxygen, for diluted PVME solution (0.1 g dm{sup -3}), decrease of LSI signal consisting of the kinetic of a first-order reaction was observed. The rate constant of LSI decrease was found to be 1.1x10{sup 3} s{sup -1} and it was attributed to the main-chain scission.

  13. Radiation crosslinking and scission of poly(vinyl methyl ether) in aqueous solution

    Science.gov (United States)

    Janik, Ireneusz; Rosiak, Janusz M.

    2002-03-01

    For a wide range of poly(vinyl methyl ether) (PMVE) concentrations (1-16 g dm -3), in anoxic conditions, polymer-derived radicals recombine in two major pathways: (i) crosslinking and (ii) disproportionation. Both these processes proceed inter- and intramolecularly. The radiation-chemical yields and kinetics of crosslinking have been studied by pulse radiolysis with light scattering intensity detection (LSI). In the absence of oxygen, G-values of intermolecular crosslinking were determined on the basis of LSI changes versus applied dose and compared with the results obtained previously for γ-irradiated samples. It has been found that the first half-life time of intermolecular crosslinking decreases with increasing dose per pulse. Addition of small amounts of macroradical scavenger (cysteamine hydrochloride) decreases, drastically, the increase of LSI signal. On increasing the PVME concentration, intermolecular crosslinking becomes more efficient. In the presence of oxygen, for diluted PVME solution (0.1 g dm -3), decrease of LSI signal consisting of the kinetic of a first-order reaction was observed. The rate constant of LSI decrease was found to be 1.1×10 3 s -1 and it was attributed to the main-chain scission.

  14. Characterization methods for radiation crosslinked poly(vinyl methyl ether) hydrogels

    Science.gov (United States)

    Schmidt, Thomas; Querner, Claudia; Arndt, Karl-Friedrich

    2003-08-01

    The paper reviews recent results of radiation crosslinking of poly(vinyl methyl ether) (PVME). It will give an overview of possible characterization methods for both, soluble and crosslinked PVME. The irradiation of aqueous low concentrated PVME solutions with γ-rays of low doses results in structural changes of PVME molecules. We are able to monitor changes in the chemical structure by spectroscopic methods (IR, NMR) as well as the changes of molecular parameters (e.g. molecular weight, molecular weight distribution, branches) by classical methods for polymer characterization (size exclusion chromatography with diverse detector systems, SLS, viscosimetry). The characterization of the network parameters (crosslinking density νc, molecular weight of the network chains Mc) of PVME bulkgels crosslinked by irradiation at high dose values by classical methods (swelling and compression measurements) provides incorrect results because of the high porosity of the gels. PVME microgel particles can be prepared by irradiation of a phase separated diluted aqueous PVME solution above their lower critical solution temperature. These microgels with decreased dimensions were characterized by SLS, DLS and field emission scanning electron microscopy.

  15. Radiation crosslinking and scission parameters for poly(vinyl methyl ether) in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Janik, I.; Kasprzak, E.; Al-Zier, A.; Rosiak, J.M. E-mail: rosiakjm@mitr.p.lodz.pl

    2003-08-01

    In oxygen-free aqueous solutions, poly(vinyl methyl ether) (PVME) was subjected to gamma irradiation. In such conditions PVME radicals recombine by way of crosslinking. The major result of crosslinking is an increase in the average molecular weight of the polymer, which close to the gelation point tends to infinity. Further irradiation increases the amount of formed gel, while the soluble fraction - sol decreases. The basic parameters related to the radiation processing are gelation dose - D{sub g}, as well as radiation yield of intermolecular crosslinking and scission, G{sub X} and G{sub S}, respectively. There are three general approaches for estimation of those parameters. The first method is based on the study of molecular weight changes before the gelation point. The second method combines the gel-sol as well as the swelling analysis results. The third one allows one to calculate the yield of crosslinking from the value of D{sub g}. All of these methods of calculation were used in this work for determination of radiation parameters and results obtained are discussed.

  16. Radiation crosslinking and scission parameters for poly(vinyl methyl ether) in aqueous solution

    Science.gov (United States)

    Janik, I.; Kasprzak, E.; Al-Zier, A.; Rosiak, J. M.

    2003-08-01

    In oxygen-free aqueous solutions, poly(vinyl methyl ether) (PVME) was subjected to gamma irradiation. In such conditions PVME radicals recombine by way of crosslinking. The major result of crosslinking is an increase in the average molecular weight of the polymer, which close to the gelation point tends to infinity. Further irradiation increases the amount of formed gel, while the soluble fraction - sol decreases. The basic parameters related to the radiation processing are gelation dose - Dg, as well as radiation yield of intermolecular crosslinking and scission, GX and GS, respectively. There are three general approaches for estimation of those parameters. The first method is based on the study of molecular weight changes before the gelation point. The second method combines the gel-sol as well as the swelling analysis results. The third one allows one to calculate the yield of crosslinking from the value of Dg. All of these methods of calculation were used in this work for determination of radiation parameters and results obtained are discussed.

  17. Characterization methods for radiation crosslinked poly(vinyl methyl ether) hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Thomas; Querner, Claudia; Arndt, Karl-Friedrich E-mail: karl-friedrich.arndt@chemie.tu-dresden.de

    2003-08-01

    The paper reviews recent results of radiation crosslinking of poly(vinyl methyl ether) (PVME). It will give an overview of possible characterization methods for both, soluble and crosslinked PVME. The irradiation of aqueous low concentrated PVME solutions with {gamma}-rays of low doses results in structural changes of PVME molecules. We are able to monitor changes in the chemical structure by spectroscopic methods (IR, NMR) as well as the changes of molecular parameters (e.g. molecular weight, molecular weight distribution, branches) by classical methods for polymer characterization (size exclusion chromatography with diverse detector systems, SLS, viscosimetry). The characterization of the network parameters (crosslinking density {nu}{sub c}, molecular weight of the network chains M{sub c}) of PVME bulkgels crosslinked by irradiation at high dose values by classical methods (swelling and compression measurements) provides incorrect results because of the high porosity of the gels. PVME microgel particles can be prepared by irradiation of a phase separated diluted aqueous PVME solution above their lower critical solution temperature. These microgels with decreased dimensions were characterized by SLS, DLS and field emission scanning electron microscopy.

  18. CCSD(T) study of the infrared spectrum of ethyl-methyl-ether isotopic varieties

    Energy Technology Data Exchange (ETDEWEB)

    Senent, M.L., E-mail: senent@iem.cfmac.csic.es [Departamento de Astrofisica Molecular e Infrarroja, Instituto de Estructura de la Materia, C.S.I.C., Serrano 121, Madrid 28006 (Spain); Ruiz, R. [Departamento de Quimica, Universidad de Burgos, Departamento de Quimica, Plaza Misael Banuelos s/n, 09001 Burgos (Spain); Villa, M. [Departamento de Quimica, UAM-I Purisima y Michoacan, s/n, CP 09340, Mexico D.F. (Mexico); Dominguez-Gomez, R. [Departamento de Ingenieria Civil, Catedra de Quimica, E.U.I.T. Obras Publicas, Universidad Politecnica de Madrid (Spain)

    2010-02-18

    Band positions for the infrared bands of various ethyl-methyl-ether isotopomers (CH{sub 3}CH{sub 2}OCH{sub 2}D, CH{sub 2}DCH{sub 2}OCH{sub 3}, CH{sub 3}CH{sub 2}OCD{sub 3}, CD{sub 3}CH{sub 2}OCH{sub 3}, CH{sub 3}CD{sub 2}OCH{sub 3}, CH{sub 3}CH{sub 2}O{sup 13}CH{sub 3}, {sup 13}CH{sub 3}CH{sub 2}OCH{sub 3}, and CH{sub 3}{sup 13}CH{sub 2}OCH{sub 3}) are determined using second order perturbation theory. For species showing G{sub 18} symmetry, band position are calculated variationally from a CCSD(T)/cc-pVTZ three-dimensional potential energy surface corrected vibrationally. Potential energy barriers, fundamental frequencies, and rotational constants for excited vibrational levels, are also provided. Calculated frequencies for CH{sub 3}CH{sub 2}OCD{sub 3} confirm experimental assignments and our predictions for the most abundant isotopomer .

  19. The effect of materials selection on metals reduction in propylene glycol methyl ether acetate, PGMEA

    Science.gov (United States)

    Entezarian, Majid; Geiger, Bob

    2016-03-01

    The trend in microelectronics fabrication is to produce nano-features measuring down to 10 nm and finer. The PPT levels of organic and inorganic contaminants in the photoresist, solvent and cleaning solutions are becoming a major processing variable affecting the process capability and defectivity. The photoresist usually contains gels, metals, and particulates that could interfere with the lithography process and cause microbridging defects. Nano filters of 5 nm polypropylene, 5 nm polyethylene, and 10 nm natural nylon were used to filter propylene glycol methyl ether acetate PGMEA containing 50 ppb of Na, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, and Pb. All filters were effective in removing trivalent Al, Cr, and Fe metals indicating the mechanism for their removal as mechanical sieving. However, the nylon was also very effective in removing the divalent metals showing adsorptive properties. Furthermore, the metal removal of the nylon membrane was studied as a function of surface chemistry. Natural and charged 40 nm nylon membranes were tested and found that charged nylon is more effective for metal removal.

  20. Microbial degradation of methyl tert-butyl ether and tert-butyl alcohol in the subsurface

    Science.gov (United States)

    Schmidt, Torsten C.; Schirmer, Mario; Weiß, Holger; Haderlein, Stefan B.

    2004-06-01

    The fate of fuel oxygenates such as methyl tert-butyl ether (MTBE) in the subsurface is governed by their degradability under various redox conditions. The key intermediate in degradation of MTBE and ethyl tert-butyl ether (ETBE) is tert-butyl alcohol (TBA) which was often found as accumulating intermediate or dead-end product in lab studies using microcosms or isolated cell suspensions. This review discusses in detail the thermodynamics of the degradation processes utilizing various terminal electron acceptors, and the aerobic degradation pathways of MTBE and TBA. It summarizes the present knowledge on MTBE and TBA degradation gained from either microcosm or pure culture studies and emphasizes the potential of compound-specific isotope analysis (CSIA) for identification and quantification of degradation processes of slowly biodegradable pollutants such as MTBE and TBA. Microcosm studies demonstrated that MTBE and TBA may be biodegradable under oxic and nearly all anoxic conditions, although results of various studies are often contradictory, which suggests that site-specific conditions are important parameters. So far, TBA degradation has not been shown under methanogenic conditions and it is currently widely accepted that TBA is a recalcitrant dead-end product of MTBE under these conditions. Reliable in situ degradation rates for MTBE and TBA under various geochemical conditions are not yet available. Furthermore, degradation pathways under anoxic conditions have not yet been elucidated. All pure cultures capable of MTBE or TBA degradation isolated so far use oxygen as terminal electron acceptor. In general, compared with hydrocarbons present in gasoline, fuel oxygenates biodegrade much slower, if at all. The presence of MTBE and related compounds in groundwater therefore frequently limits the use of in situ biodegradation as remediation option at gasoline-contaminated sites. Though degradation of MTBE and TBA in field studies has been reported under oxic

  1. Microbial degradation and fate in the environment of methyl tert-butyl ether and related fuel oxygenates.

    Science.gov (United States)

    Fayolle, F; Vandecasteele, J P; Monot, F

    2001-08-01

    Oxygenates, mainly methyl tert-butyl ether (MTBE), are commonly added to gasoline to enhance octane index and improve combustion efficiency. Other oxygenates used as gasoline additives are ethers such as ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and alcohols such as tert-butyl alcohol (TBA). As a result of its wide use, MTBE has been detected, mainly in the USA, in groundwater and surface waters, and is a cause of concern because of its possible health effects and other undesirable consequences. MTBE is a water-soluble and mobile compound that generates long pollution plumes in aquifers impacted by gasoline releases from leaking tanks. Field observations concur in estimating that, because of recalcitrance to biodegradation, natural attenuation is slow (half-life of at least 2 years). However, quite significant advances have been made in recent years concerning the microbiology of the degradation of MTBE and other oxygenated gasoline additives. The recalcitrance of these compounds results from the presence in their structure of an ether bond and of a tertiary carbon structure. For the most part, only aerobic microbial degradation systems have been reported so far. Consortia capable of mineralizing MTBE have been selected. Multiple instances of the cometabolism of MTBE with pure strains or with microflorae, growing on n-alkanes, isoalkanes, cyclohexane or ethers (diethyl ether, ETBE), have been described. MTBE was converted into TBA in all cases and was sometimes further degraded, but it was not used as a carbon source by the pure strains. However, mineralization of MTBE and TBA by several pure bacterial strains using these compounds as sole carbon and energy source has recently been reported. The pathways of metabolism of MTBE involve the initial attack by a monooxygenase. In several cases, the enzyme was characterized as a cytochrome P-450. After oxygenation, the release of a C -unit as formaldehyde or formate leads to the production of TBA

  2. Urinary methyl tert-butyl ether and benzene as biomarkers of exposure to urban traffic.

    Science.gov (United States)

    Campo, Laura; Cattaneo, Andrea; Consonni, Dario; Scibetta, Licia; Costamagna, Paolo; Cavallo, Domenico M; Bertazzi, Pier Alberto; Fustinoni, Silvia

    2011-02-01

    Methyl tert-butyl ether (MTBE) and benzene are added to gasoline to improve the combustion process and are found in the urban environment as a consequence of vehicular traffic. Herein we evaluate urinary MTBE (MTBE-U) and benzene (BEN-U) as biomarkers of exposure to urban traffic. Milan urban policemen (130 total) were investigated in May, July, October, and December for a total of 171 work shifts. Personal exposure to airborne benzene and carbon monoxide (CO), and atmospheric data, were measured during the work shift, while personal characteristics were collected by a questionnaire. A time/activity diary was completed by each subject during the work shift. Spot urine samples were obtained for the determination of MTBE-U and BEN-U. Median personal exposure to CO and airborne benzene were 3.3 mg/m(3) and 9.6 μg/m(3), respectively; median urinary levels in end-of-shift (ES) samples were 147 ng/L (MTBE-U) and 207 ng/L (BEN-U). The time spent on traffic duty at crossing was about 40% of work time. Multiple linear regression models, taking into account within-subject correlations, were applied to investigate the role of urban pollution, atmospheric conditions, job variables and personal characteristics on the level of biomarkers. MTBE-U was influenced by the month of sampling and positively correlated to the time spent in traffic guarding, CO exposure and atmospheric pressure, while negatively correlated to wind speed (R(2) for total model 0.63, P<0.001). BEN-U was influenced by the month and smoking habit, and positively correlated to urinary creatinine; moreover, an interaction between CO and smoking was found (R(2)=0.62, P<0.001). These results suggest that MTBE-U is a reliable marker for assessing urban traffic exposure, while BEN-U is determined mainly by personal characteristics.

  3. Removal of Methyl Tert-Butyl Ether (MTBE from Contaminated Water by Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    A Eslami

    2009-06-01

    Full Text Available "nBackground: Methyl tert-butyl ether (MTBE has been commercially used as an octane enhancer to replace tetraethyl lead in gasoline since 1979. The high mobility, water solubility, and resistance to natural attenuation associated with MTBE may re­sult in contamination of ground and surface waters. In this investigation the degradation of aqueous MTBE at relatively high concentrations was studied by UV-vis/TiO2/O2 photocatalytic process. The effect of important operational parameters such as pH, oxygen flow, catalyst loading, and irradiation time were also studied."nMethods:Concentration of MTBE and intermediates such as tert-butyl formate (TBF and tert-butyl alcohol (TBA were meas­ured using a gas chromatograph equipped with flam ionization detector and combined with headspace sampler."nResults: The time required for complete degradation increased from 15 to 150 min, when the initial concentration was in­creased from 10 to 500 mg/L. The first order rate constant for degradation of MTBE from the hydroxyl radical was esti­mated to be 0.266 to 0.033 min-1 as the concentration increased from 10 to 500 mg/L. Study on the overall mineralization moni­tored by total organic carbon (TOC analysis showed that in the initial concentration of 100 mg/L MTBE, complete min­eralization was obtained after 110 min under UV-vis/TiO2/O2 photocatalytic process."nConclusion: The data presented in this paper clearly indicate that UV/TiO2/O2 advanced oxidation process provides an effi­cient treatment alternative for the remediation of MTBE contaminated water.  

  4. Risk characterization of methyl tertiary butyl ether (MTBE) in tap water.

    Science.gov (United States)

    Stern, B R; Tardiff, R G

    1997-12-01

    Methyl tertiary butyl ether (MTBE) can enter surface water and groundwater through wet atmospheric deposition or as a result of fuel leaks and spills. About 30% of the U.S. population lives in areas where MTBE is in regular use. Ninety-five percent of this population is unlikely to be exposed to MTBE in tap water at concentrations exceeding 2 ppb, and most will be exposed to concentrations that are much lower and may be zero. About 5% of this population may be exposed to higher levels of MTBE in tap water, resulting from fuel tank leaks and spills into surface or groundwater used for potable water supplies. This paper describes the concentration ranges found and anticipated in surface and groundwater, and estimates the distribution of doses experienced by humans using water containing MTBE to drink, prepare food, and shower/bathe. The toxic properties (including potency) of MTBE when ingested, inhaled, and in contact with the skin are summarized. Using a range of human toxic potency values derived from animal studies, margins of exposure (MOE) associated with alternative chronic exposure scenarios are estimated to range from 1700 to 140,000. Maximum concentrations of MTBE in tap water anticipated not to cause adverse health effects are determined to range from 700 to 14,000 ppb. The results of this analysis demonstrate that no health risks are likely to be associated with chronic and subchronic human exposures to MTBE in tap water. Although some individuals may be exposed to very high concentrations of MTBE in tap water immediately following a localized spill, these exposures are likely to be brief in duration due to large-scale dilution and rapid volatilization of MTBE, the institution of emergency response and remediation measures to minimize human exposures, and the low taste and odor thresholds of MTBE which ensure that its presence in tap water is readily detected at concentrations well below the threshold for human injury.

  5. LIDEM unit for the production of methyl tert-butyl ether from butanes

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, M.G.; Zadvornov, M.A.

    1994-09-01

    One of the basic problems in the production of motor fuels is how to obtain high-octane unleaded gasolines that will meet today`s ecological requirements. The term {open_quotes}reformulated gasolines{close_quotes} has come into general use throughout the world to denote fuels with a certain chemical composition. These gasolines consist of preselected components; as shown by worldwide experience, they must include oxygen-containing compounds that are distinguished by high octane numbers and low reactivities. Standards in effect in the United States, Japan, and certain Western European countries require that automotive gasolines must contain at least 2-4% by weight of oxygen-containing compounds (calculated as oxygen). In the last 15 years, in order to meet these requirements, production has been set up in various countries for the manufacture of high-octane oxygen-containing components known as oxygenates. The most common of these is methyl tert-butyl ether (MTBE), obtained by etherification of isobutene by methanol. Process technology developed by this last organization was used as the basis for constructing a unit in the Nizhnekamskneftekhim Production Association and at the Mazheikyai Petroleum Refinery in Lithuania. MTBE production has been held back mainly by a shortage of isobutene, which is obtained mainly from butane-butene cuts produced in cat crackers. In order to alleviate this shortage, it has been proposed that MTBE should be obtained from saturated C{sub 4} hydrocarbons that are recovered in processing oilfield associated gas, and also in the refinery from primary distillation units, catalytic reformers, and hydrocrackers. A working design was developed in 1991-1992 by Lengiproneftekhim for a basically new combination unit designed for the processing of saturated C{sub 4} hydrocarbons, which has been termed the LIDEM unit (Leningrad - isomerization - dehydrogenation - MTBE).

  6. Plasma graft of poly(ethylene glycol) methyl ether methacrylate (PEGMA) on RGP lens surface for reducing protein adsorption

    Science.gov (United States)

    Shiheng, Yin; Li, Ren; Yingjun, Wang

    2017-01-01

    Poly(ethylene glycol) methyl ether methacrylate (PEGMA) was grafted on fluorosilicone acrylate rigid gas permissible contact lens surface by means of argon plasma induced polymerization to improve surface hydrophilicity and reduce protein adsorption. The surface properties were characterized by contact angle measurement, x-ray photoelectron spectroscopy (XPS) and atomic force microscopy respectively. The surface protein adsorption was evaluated by lysozyme solution immersion and XPS analysis. The results indicated that a thin layer of PEGMA was successfully grafted. The surface hydrophilicity was bettered and surface free energy increased. The lysozyme adsorption on the lens surface was reduced greatly. The study was supported by National Natural Science Foundation of China (No. 51273072).

  7. The potential of di-methyl ether (DME) as an alternative fuel for compression-ignition engines: A review

    OpenAIRE

    Arcoumanis, C.; Bae, C.; Crookes, R.; Kinoshita, E

    2008-01-01

    This paper reviews the properties and application of di-methyl ether (DME) as a candidate fuel for compression-ignition engines. DME is produced by the conversion of various feedstock such as natural gas, coal, oil residues and bio-mass. To determine the technical feasibility of DME, the review compares its key properties with those of diesel fuel that are relevant to this application. DME’s diesel engine-compatible properties are its high cetane number and low auto-ignition temperature. In a...

  8. 3-(Imidazolyl methyl)-3-aza-bicyclo[3.1.0]hexan-6-yl)methyl ethers: a novel series of mGluR2 positive allosteric modulators.

    Science.gov (United States)

    Zhang, Lei; Rogers, Bruce N; Duplantier, Allen J; McHardy, Stanley F; Efremov, Ivan; Berke, Helen; Qian, Weimin; Zhang, Andy Q; Maklad, Noha; Candler, John; Doran, Angela C; Lazzaro, John T; Ganong, Alan H

    2008-10-15

    The synthesis and structure-activity relationship (SAR) of a novel series of 3-(imidazolyl methyl)-3-aza-bicyclo[3.1.0]hexan-6-yl)methyl ethers, derived from a high throughput screening (HTS), are described. Subsequent optimization led to identification of potent, metabolically stable and orally available mGluR2 positive allosteric modulators (PAMs).

  9. Thermochemical properties of methyl-substituted cyclic alkyl ethers and radicals for oxiranes, oxetanes, and oxolanes: C-H bond dissociation enthalpy trends with ring size and ether site.

    Science.gov (United States)

    Auzmendi-Murua, Itsaso; Charaya, Sumit; Bozzelli, Joseph W

    2013-01-17

    Cyclic ethers are an important product from the gas-phase reactions of hydrocarbon radicals with molecular oxygen in the atmospheric chemistry of diolefins and in low to moderate temperature combustion and oxidation reaction systems. They are also important in organic synthesis. Structures, and fundamental thermochemical parameters-enthalpy (ΔH°(f,298)), entropy (S°(298)), and heat capacity (C(p)(T))-have been calculated for a series of cyclic alkyl ethers and their carbon centered radicals. Enthalpies of formation (ΔH°(f,298)) are determined at the B3LYP/6-31G(d,p), B3LYP/6-31G(2d,2p), and CBS-QB3 levels using several work reactions for each species. Entropy (S) and heat capacity (C(p)(T)) values from vibration, translational, and external rotational contributions are calculated using the rigid-rotor-harmonic-oscillator approximation based on the vibration frequencies and structures obtained from the density functional studies. Contributions from the internal methyl rotors are substituted for torsion frequencies. Calculated enthalpies of formation for a series of 12 cyclic ethers and methyl substituted cyclic ethers are in good agreement with available literature values. C-H bond dissociation enthalpies are reported for 28 carbon sites of 3 to 5 member ring cyclic ethers for use in understanding effects of the ring and the ether oxygen on kinetics and stability. Trends in carbon-hydrogen bond energies for the ring and methyl substituents relative to ring size and to distance from the ether group are described.

  10. Biodegradation of methyl tert-butyl ether and other fuel oxygenates by a new strain, Mycobacterium austroafricanum IFP 2012.

    Science.gov (United States)

    François, Alan; Mathis, Hugues; Godefroy, Davy; Piveteau, Pascal; Fayolle, Françoise; Monot, Frédéric

    2002-06-01

    A strain that efficiently degraded methyl tert-butyl ether (MTBE) was obtained by initial selection on the recalcitrant compound tert-butyl alcohol (TBA). This strain, a gram-positive methylotrophic bacterium identified as Mycobacterium austroafricanum IFP 2012, was also able to degrade tert-amyl methyl ether and tert-amyl alcohol. Ethyl tert-butyl ether was weakly degraded. tert-Butyl formate and 2-hydroxy isobutyrate (HIBA), two intermediates in the MTBE catabolism pathway, were detected during growth on MTBE. A positive effect of Co2+ during growth of M. austroafricanum IFP 2012 on HIBA was demonstrated. The specific rate of MTBE degradation was 0.6 mmol/h/g (dry weight) of cells, and the biomass yield on MTBE was 0.44 g (dry weight) per g of MTBE. MTBE, TBA, and HIBA degradation activities were induced by MTBE and TBA, and TBA was a good inducer. Involvement of at least one monooxygenase during degradation of MTBE and TBA was shown by (i) the requirement for oxygen, (ii) the production of propylene epoxide from propylene by MTBE- or TBA- grown cells, and (iii) the inhibition of MTBE or TBA degradation and of propylene epoxide production by acetylene. No cytochrome P-450 was detected in MTBE- or TBA-grown cells. Similar protein profiles were obtained after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude extracts from MTBE- and TBA-grown cells. Among the polypeptides induced by these substrates, two polypeptides (66 and 27 kDa) exhibited strong similarities with known oxidoreductases.

  11. Molecular dynamics simulations of the hydration of poly(vinyl methyl ether): Hydrogen bonds and quasi-hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    WU RongLiang; JI Qing; KONG Bin; YANG XiaoZhen

    2008-01-01

    Atomistic detailed hydration structures of poly(vinyl methyl ether) (PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution func-tions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain, and there still exists a significant amount (10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentra-tion as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer, which leads to inefficient con-tacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds, but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry (DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME, which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition, at the concentration of 86%, each ether oxygen atom bonded with water is assigned 1.56 water molecules on average, and 'free' water molecules emerge at the concentration of around 54%.

  12. Molecular dynamics simulations of the hydration of poly(vinyl methyl ether):Hydrogen bonds and quasi-hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Atomistic detailed hydration structures of poly(vinyl methyl ether)(PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution functions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain,and there still exists a significant amount(10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentration as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer,which leads to inefficient contacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds,but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry(DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME,which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition,at the concentration of 86%,each ether oxygen atom bonded with water is assigned 1.56 water molecules on average,and ’free’ water molecules emerge at the concentration of around 54%.

  13. Aberrant 5'-CpG Methylation of Cord Blood TNFα Associated with Maternal Exposure to Polybrominated Diphenyl Ethers.

    Directory of Open Access Journals (Sweden)

    Tyna Dao

    Full Text Available Growing evidence suggests that maternal exposures to endocrine disrupting chemicals during pregnancy may lead to poor pregnancy outcomes and increased fetal susceptibility to adult diseases. Polybrominated diphenyl ethers (PBDEs, which are ubiquitously used flame-retardants, could leach into the environment; and become persistent organic pollutants via bioaccumulation. In the United States, blood PBDE levels in adults range from 30-100 ng/g- lipid but the alarming health concern revolves around children who have reported blood PBDE levels 3 to 9-fold higher than adults. PBDEs disrupt endocrine, immune, reproductive and nervous systems. However, the mechanism underlying its adverse health effect is not fully understood. Epigenetics is a possible biological mechanism underlying maternal exposure-child health outcomes by regulating gene expression without changes in the DNA sequence. We sought to examine the relationship between maternal exposure to environmental PBDEs and promoter methylation of a proinflammatory gene, tumor necrosis factor alpha (TNFα. We measured the maternal blood PBDE levels and cord blood TNFα promoter methylation levels on 46 paired samples of maternal and cord blood from the Boston Birth Cohort (BBC. We showed that decreased cord blood TNFα methylation associated with high maternal PBDE47 exposure. CpG site-specific methylation showed significantly hypomethylation in the girl whose mother has a high blood PBDE47 level. Consistently, decreased TNFα methylation associated with an increase in TNFα protein level in cord blood. In conclusion, our finding provided evidence that in utero exposure to PBDEs may epigenetically reprogram the offspring's immunological response through promoter methylation of a proinflammatory gene.

  14. Short-term oral toxicity of butyl ether, ethyl hexyl ether, methyl heptyl ether and 1,6-dimethoxyhexane in male rats and the role of 2-methoxyacetic acid.

    Science.gov (United States)

    Poon, Raymond; Wade, Michael; Valli, Victor E; Chu, Ih

    2005-10-15

    A 4-week oral study was conducted in male rats to characterize and compare the toxicity of four aliphatic ethers (butyl ether, BE; ethyl hexyl ether, EHxE; methyl heptyl ether, MHpE; and 1,6-dimethoxyhexane, DMH) which have been proposed as high-cetane diesel additives. Male Sprague-Dawley rats (280+/-20 g) were divided into groups of seven animals each and were administered by gavage low (2mg/kg body weight), medium (20mg/kg) or high (200mg/kg) doses of BE, EHxE, or MHpE, 5 days per week for 4 weeks. Another group of animals was administered DMH at 200mg/kg while the control group received the vehicle (corn oil at 1 ml/100g bw) only. At the end of the treatment period, relative testis weights and thymus weights were significantly decreased in the DMH group but not in animals receiving BE, EHxE, or MHpE. Microscopic examination revealed degeneration of the seminiferous tubules and reduction of sperm density in the epididymides in the DMH treatment group. Urinary creatine/creatinine ratio, a sensitive indicator of testicular damage, was markedly elevated in the DMH treated animals but not in those treated with BE, EHxE, or MHpE. In the bone marrow, DMH caused mild dyserythropoiesis and dysthrombopoiesis, while BE, EHxE, and MHpE produced mild increases in granulocytes and myelocyte/erythrocyte ratio. All four ethers at 200mg/kg caused mild histological changes in the thyroid but no significant modulation in the circulating thyroxin (T4) or triiodothyronine (T3) levels. All four ethers produced hepatic effects at 200mg/kg consisting of mild, adaptive histological changes, increased urinary ascorbic acid output, and elevation in the activities of one or more xenobiotic metabolizing enzymes (benzyloxyresorufin-O-dealkylase, UDP-glucuronosyltransferase, glutathione-S-transferases). The level of 2-methoxyacetic acid (MAA), a known testicular and developmental toxin, was significantly increased in the urine and plasma of animals treated with DMH but not in those

  15. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

    2015-01-01

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...

  16. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin;

    2015-01-01

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated...

  17. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  18. A COMPARISON BETWEEN THE MORPHOLOGY OF SEMICRYSTALLINE POLYMER BLENDS OF POLY(EPSILON-CAPROLACTONE)/POLY(VINYL METHYL-ETHER) AND POLY(EPSILON-CAPROLACTONE)/(STYRENE-ACRYLONITRILE)

    NARCIS (Netherlands)

    OUDHUIS, AACM; THIEWES, HJ; VANHUTTEN, PF; TENBRINKE, G

    1994-01-01

    The morphology of polymer blends of poly(epsilon-caprolactone) (PCL) and poly(vinyl methyl ether) (PVME) is compared with that of PCL and a random copolymer of styrene and acrylonitrile (SAN). The main objective is to determine the influence of the glass transition temperature of the amorphous compo

  19. A comparative study of biodiesel production using methanol, ethanol, and tert-butyl methyl ether (MTBE) under supercritical conditions.

    Science.gov (United States)

    Farobie, Obie; Matsumura, Yukihiko

    2015-09-01

    In this study, biodiesel production under supercritical conditions among methanol, ethanol, and tert-butyl methyl ether (MTBE) was compared in order to elucidate the differences in their reaction behavior. A continuous reactor was employed, and experiments were conducted at various reaction temperatures (270-400 °C) and reaction times (3-30 min) and at a fixed pressure of 20 MPa and an oil-to-reactant molar ratio of 1:40. The results showed that under the same reaction conditions, the supercritical methanol method provided the highest yield of biodiesel. At 350 °C and 20 MPa, canola oil was completely converted to biodiesel after 10, 30, and 30 min in the case of - supercritical methanol, ethanol, and MTBE, respectively. The reaction kinetics of biodiesel production was also compared for supercritical methanol, ethanol, and MTBE.

  20. Energy analysis for the production of biodiesel in a spiral reactor using supercritical tert-butyl methyl ether (MTBE).

    Science.gov (United States)

    Farobie, Obie; Matsumura, Yukihiko

    2015-11-01

    In this study, energy analysis was conducted for the production of biodiesel in a spiral reactor using supercritical tert-butyl methyl ether (MTBE). This study aims to determine the net energy ratio (NER) and energy efficiency for the production of biodiesel using supercritical MTBE and to verify the effectiveness of the spiral reactor in terms of heat recovery efficiency. The analysis results revealed that the NER for this process was 0.92. Meanwhile, the energy efficiency was 0.98, indicating that the production of biodiesel in a spiral reactor using supercritical MTBE is an energy-efficient process. By comparing the energy supply required for biodiesel production between spiral and conventional reactors, the spiral reactor was more efficient than the conventional reactor.

  1. Poly(methyl vinyl ether-alt-maleic acid)-functionalized porous silicon nanoparticles for enhanced stability and cellular internalization.

    Science.gov (United States)

    Shahbazi, Mohammad-Ali; Almeida, Patrick V; Mäkilä, Ermei; Correia, Alexandra; Ferreira, Mónica P A; Kaasalainen, Martti; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

    2014-03-01

    Currently, developing a stable nanocarrier with high cellular internalization and low toxicity is a key bottleneck in nanomedicine. Here, we have developed a successful method to covalently conjugate poly(methyl vinyl ether-co-maleic acid) (PMVE-MA) copolymer on the surface of (3-aminopropyl)triethoxysilane-functionalized thermally carbonized porous silicon nanoparticles (APSTCPSi NPs), forming a surface negatively charged nanovehicle with unique properties. This polymer conjugated NPs could modify surface smoothness, charge, and hydrophilicity of the developed NPs, leading to considerable improvement in the colloidal and plasma stabilities via enhanced suspensibility and charge repulsion. Furthermore, despite the surface negative charge of the polymer-conjugated NPs, the cellular internalization was increased in both MDA-MB-231 and MCF-7 breast cancer cells. These results provide a proof-of-concept evidence that such polymer-based PSi nanocomposite can be extensively used as a promising candidate for intracellular drug delivery.

  2. Biological Activity of Methyl tert-butyl Ether in Relation to Soil Microorganisms has a Negative Environmental Impact

    Directory of Open Access Journals (Sweden)

    Gholam H.S. Bonjar

    2005-01-01

    Full Text Available Fuel oxygenates are added to gasoline to enhance combustion efficiency of automobiles and reduce air pollution. Methyl tert-butyl ether (MTBE is the most commonly used oxygenate because of its low cost, high-octane level and ease of blending with gasoline. However, due to its water solubility, high mobility and low biodegradability it leaches in soil subsurface at the speed of groundwater. Amending gasoline with MTBE has made a widespread contamination of groundwater, surface waters in coastal environments and at low levels in well water. Although current public concern about MTBE contamination is widely discussed, but its adverse effects on soil micro flora is not yet understood. Soil Streptomycetes are beneficial to soil productivity and are of the major contributors to the biological buffering of soils having antagonistic activity against wide spectrum of pathogenic bacteria and fungi. Streptomyceticidal activity of Methyl tert-butyl ether (MTBE is being reported here. Adverse effect of MTBE against four soil-inhabitant Streptomyces spp. isolates and two plant root-pathogens was investigated. To elucidate antimicrobial activity of MTBE, it was tested against four soil isolates of Streptomyces; a plant bacterial-pathogen, Erwinia carotovora and a plant root fungal-pathogen, Fusarium solani. MTBE did not reveal any growth inhibitory-activity against E. carotovora and F. solani but showed strong inhibitory effect against Streptomyces spp. isolates. The Minimum Inhibitory Concentration (MIC was 1/800 of the original MTBE. Fuel leaks and spills can adversely suppress or eliminate the Streptomyces role in the soil causing alteration in the balance of soil micro flora. This change will lead to domination of microorganisms with adverse biological or ecological effects. Fortunately, major oil companies have decided to phase out MTBE from automobile fuels because of its adverse effect on environment and human health.

  3. TAME (tertiary-amyl-methyl ether) gasoline additive production process development; Desenvolvimento do processo de producao de TAME-aditivo para gasolina

    Energy Technology Data Exchange (ETDEWEB)

    Lovisi, Humberto [Petroflex Industria e Comercio S.A., Duqye de Caxias, RJ (Brazil); Piccoli, Ricardo [COPESUL, Companhia Petroquimica do Sul, Triunfo, RS (Brazil)

    1992-12-31

    PETROFLEX and COPESUL jointly developed a TAME production process. Tertiary-amyl-methyl ether (TAME) is obtained by the methoxylation of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in a C{sub s} cut over a sulfonic acid resin. Process was developed on the basis of pilot plant and batch experiments. A simplified process flow-sheet and pilot plant data are presented. Isoamylenes conversions higher than 70% were achieved with low by-products formation. (author) 22 refs., 2 figs., 2 tabs.

  4. Feedback regulation of beta-thujaplicin production and formation of its methyl ether in a suspension culture of Cupressus lusitanica.

    Science.gov (United States)

    Yamada, Junko; Fujita, Koki; Sakai, Kokki

    2002-07-01

    Suspension cell cultures of Cupressus lusitanica produce beta-thujaplicin, a tropolone found mostly in Cupressaceae heartwood. The factors controlling beta-thujaplicin accumulation in this cell culture system were investigated. Initial cell density of the cultures did not affect beta-thujaplicin levels, though initial addition of beta-thujaplicin suppressed its de novo production. When beta-thujaplicin accumulation reached a certain level (ca. 40 mg/l) in the medium, the cultures seemed to cease beta-thujaplicin production. However, beta-thujaplicin productivity was restored when the beta-thujaplicin-containing medium was exchanged for fresh medium; the formation of 2-methoxy-6-(methylethyl)cyclohepta-2,4,6-trien-1-one, an isomer of methylated beta-thujaplicin, in medium was also observed. These results suggest that beta-thujaplicin synthesis was regulated by product feedback mechanism in this cell line, and that excess accumulation of beta-thujaplicin is relieved by conversion of beta-thujaplicin to its methyl ether.

  5. Distribution of methyl tert-butyl ether (MTBE) and selected water-quality constituents in the surficial aquifer at the Dover National Test Site, Dover Air Force Base, Delaware, 2001

    Science.gov (United States)

    Stewart, Marie; Guertal, William R.; Barbaro, Jeffrey R.; McHale, Timothy J.

    2004-01-01

    A joint study by the Dover National Test Site, Dover Air Force Base, Delaware, and the U.S. Geological Survey was conducted from June 27 through July 18, 2001, to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site. This report provides a summary assessment of the distribution of methyl tert-butyl ether and a preliminary screening of selected constituents that may affect natural attenuation and remediation demonstrations at the Dover National Test Site. The information gathered during this study is designed to assist potential remedial investigators who are considering conducting a methyl tert-butyl ether remedial demonstration at the test site. In addition, the study supported a planned enhanced bioremediation demonstration and assisted the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. A direct-push drill rig was used to collect a total of 147 ground-water samples (115 VOC samples and 32 quality-assurance samples) at varying depths. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloro-ethene, 1.14 micrograms per liter of trichloro-ethene, 2.65 micrograms per liter of tetrachloro-ethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest concentrations of methyl tert-butyl ether were detected in the surficial aquifer from ?4.6 to 6.4 feet mean sea level; however, methyl tert

  6. Metabolism of methyl tert-butyl ether and other gasoline ethers by human liver microsomes and heterologously expressed human cytochromes P450: identification of CYP2A6 as a major catalyst.

    Science.gov (United States)

    Hong, J Y; Wang, Y Y; Bondoc, F Y; Lee, M; Yang, C S; Hu, W Y; Pan, J

    1999-10-01

    To reduce the production of carbon monoxide and other pollutants in motor vehicle exhaust, methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) are added to gasoline as oxygenates for more complete combustion. Previously, we demonstrated that human liver is active in metabolizing MTBE to tert-butyl alcohol (TBA) and that cytochrome P450 (CYP) enzymes play a critical role in the metabolism of MTBE. The present study demonstrates that human liver is also active in the oxidative metabolism of ETBE and TAME. A large interindividual variation in metabolizing these gasoline ethers was observed in 15 human liver microsomal samples. The microsomal activities in metabolizing MTBE, ETBE, and TAME were highly correlated among each other (r, 0.91-0. 96), suggesting that these ethers are metabolized by the same enzyme(s). Correlation analysis of the ether-metabolizing activities with individual CYP enzyme activities in the liver microsomes showed that the highest degree of correlation was with human CYP2A6 (r, 0. 90-0.95), which is constitutively expressed in human livers and known to be polymorphic. CYP2A6 displayed the highest turnover number in metabolizing gasoline ethers among a battery of human CYP enzymes expressed in human B-lymphoblastoid cells. Kinetic studies on MTBE metabolism with three human liver microsomes exhibited apparent Km values that ranged from 28 to 89 microM and the V(max) values from 215 to 783 pmol/min/mg, with similar catalytic efficiency values (7.7 to 8.8 microl/min/mg protein). Metabolism of MTBE, ETBE, and TAME by human liver microsomes was inhibited by coumarin, a known substrate of human CYP2A6, in a concentration-dependent manner. Monoclonal antibody against human CYP2A6 caused a significant inhibition (75% to 95%) of the metabolism of MTBE, ETBE, and TAME in human liver microsomes. Taken together, these results clearly indicate that in human liver, CYP2A6 is the major enzyme responsible for the

  7. An efficient and highly selective ortho-tert-butylation of p-cresol with methyl tert-butyl ether catalyzed by sulfonated ionic liquids

    Directory of Open Access Journals (Sweden)

    Alamdari Reza Fareghi

    2014-01-01

    Full Text Available A novel series of sulfonic acid-functionalized ionic liquids (SFILs was found to act as efficient catalysts for ortho-tert-butylation of p-cresol with methyl tert-butyl ether (MTBE as the tert-butylating agent without an added solvent. The mono o-tert-butylated product was obtained in up to 80.4% isolated yield and 95.2% selectivity under such green conditions. No O-tert-butylated byproducts were formed.

  8. Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China.

    Science.gov (United States)

    Hu, Dalin; Yang, Jianping; Liu, Yungang; Zhang, Wenjuan; Peng, Xiaowu; Wei, Qinzhi; Yuan, Jianhui; Zhu, Zhiliang

    2016-02-06

    Methyl tertiary butyl ether (MTBE), a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs) in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p operating workers, and 0.026 to 0.049 per 10⁶ for support staff, which are below the typical target range for risk management of 1 × 10(-6) to 1 × 10(-4); The hazard quotients (HQs) for all subjects were exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

  9. Prolonged Hypocalcemic Effect by Pulmonary Delivery of Calcitonin Loaded Poly(Methyl Vinyl Ether Maleic Acid Bioadhesive Nanoparticles

    Directory of Open Access Journals (Sweden)

    J. Varshosaz

    2014-01-01

    Full Text Available The purpose of the present study was to design a pulmonary controlled release system of salmon calcitonin (sCT. Therefore, poly(methyl vinyl ether maleic acid [P(MVEMA] nanoparticles were prepared by ionic cross-linking method using Fe2+ and Zn2+ ions. Physicochemical properties of nanoparticles were studied in vitro. The stability of sCT in the optimized nanoparticles was studied by electrophoretic gel method. Plasma calcium levels until 48 h were determined in rats as pulmonary-free sCT solution or nanoparticles (25 μg·kg−1, iv solution of sCT (5 μg·kg−1, and pulmonary blank nanoparticles. The drug remained stable during fabrication and tests on nanoparticles. The optimized nanoparticles showed proper physicochemical properties. Normalized reduction of plasma calcium levels was at least 2.76 times higher in pulmonary sCT nanoparticles compared to free solution. The duration of hypocalcemic effect of pulmonary sCT nanoparticles was 24 h, while it was just 1 h for the iv solution. There was not any significant difference between normalized blood calcium levels reduction in pulmonary drug solution and iv injection. Pharmacological activity of nanoparticles after pulmonary delivery was 65% of the iv route. Pulmonary delivery of P(MVEMA nanoparticles of sCT enhanced and prolonged the hypocalcemic effect of the drug significantly.

  10. Biodegradation of methyl tert-butyl ether by cometabolism with hexane in biofilters inoculated with Pseudomonas aeruginosa.

    Science.gov (United States)

    Salazar, Margarita; Morales, Marcia; Revah, Sergio

    2012-01-01

    Biodegradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with gaseous hexane (n-hexane > 95%) was investigated using Pseudomonas aeruginosa utilizing short chain aliphatic hydrocarbon (C(5)-C(8)). Kinetic batch experiments showed that MTBE was degraded even when hexane was completely exhausted with a cometabolic coefficient of 1.06 ± 0.16 mg MTBE mg hexane(-1). Intermediate tert-butyl alcohol (TBA) accumulation was observed followed by its gradual consumption. A maximum MTBE elimination capacity (EC(MAX)) of 35 g m(-3) h(-1) and removal efficiency (RE) of 70% were attained in mineral medium amended biofilters having an empty bed residence time (EBRT) of 1 min. For these experimental conditions, a maximum hexane EC of approximately 60 g m(-3) h(-1) was obtained at a load of 75 g m(-3) h(-1). Experiments under transient conditions revealed a competitive substrate interaction between MTBE and hexane. Biomass densities between 5.8 and 12.6 g L(biofilter) (-1) were obtained. Nevertheless, production of biopolymers caused non-uniform distribution flow rates that reduced the performance. Residence time distribution profiles showed an intermediate dispersion flow rate with a dispersion coefficient of 0.8 cm(2) s(-1).

  11. Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wei-hong; CHEN Jian-meng; LU Zheng; CHEN Dong-zhi; CHEN Xiao

    2007-01-01

    The contamination of methyl tert-butyl ether (MTBE) in underground waters has become a widely concerned problem all over the world. In this study, a novel closed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PM1, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen (DO) levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tert-butyl alcohol,isopronol and acetone were the main intermediate products.

  12. Separator Membrane from Crosslinked Poly(Vinyl Alcohol and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride

    Directory of Open Access Journals (Sweden)

    Charu Vashisth Rohatgi

    2015-03-01

    Full Text Available In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride (PMVE-MA. Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity, thermal and electrochemical properties using differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, thermo-gravimetric analysis (TGA and electrochemical impedance spectroscopy (EIS. The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications.

  13. Methyl tert-butyl ether (MTBE) in public and private wells in New Hampshire: Occurrence, factors, and possible implications

    Science.gov (United States)

    Ayotte, J.D.; Argue, D.M.; McGarry, F.J.; Degnan, J.R.; Hayes, L.; Flanagan, S.M.; Helsel, D.R.

    2008-01-01

    Methyl tert-butyl ether (MTBE) concentrations ???0.2 ??g/L were found in samples of untreated water in 18% of public-supply wells (n = 284) and 9.1% of private domestic wells (n = 264) sampled in 2005 and 2006 in New Hampshire. In counties that used reformulated gasoline (RFG), MTBE occurred at or above 0.2 ??g/L in 30% of public- and 17% of private-supply wells. Additionally, 52% of public-supply wells collocated with fuel storage and 71% of mobile home park wells had MTBE. MTBE occurrence in public-supply wells was predicted by factors such as proximity to sources of fuel, land use, and population density, as well as low pH and distance from mapped lineaments. RFG use, land-use variables, and pH were important predictors of private-well MTBE occurrence. Variables representing sources of MTBE, such as the distance to known fuel sources, were not significant predictors of MTBE occurrence in private-supply wells. It is hypothesized that private wells may become contaminated from the collective effects of sources in high population areas and from undocumented incidental releases from onsite or proximal gasoline use. From 2003 to 2005, MTBE occurrence decreased in 63 public-supply wells and increased in 60 private-supply wells, but neither trend was statistically significant. ?? 2008 American Chemical Society.

  14. The efficient photocatalytic degradation of methyl tert-butyl ether under Pd/ZnO and visible light irradiation.

    Science.gov (United States)

    Seddigi, Zaki S; Ahmed, Saleh A; Bumajdad, Ali; Danish, Ekram Y; Shawky, Ahmed M; Gondal, Mohammed A; Soylak, Mustafa

    2015-01-01

    Methyl tert-butyl ether is a commonly used fuel oxygenate that is present in gasoline. It was introduced to eliminate the use of leaded gasoline and to improve the octane quality because it aids in the complete combustion of fuel by supplying oxygen during the combustion process. Over the past decade, the use of MTBE has increased tremendously worldwide. For obvious reasons relating to accidental spillage, MTBE started to appear as an environmental and human health threat because of its nonbiodegradable nature and carcinogenic potential, respectively. In this work, MTBE was degraded with the help of an advanced oxidation process through the use of zinc oxide as a photocatalyst in the presence of visible light. A mixture of 200 mg of zinc oxide in 350 mL of 50 ppm MTBE aqueous solution was irradiated with visible light for a given time. The complete degradation of MTBE was recorded, and approximately 99% photocatalytic degradation of 100 ppm MTBE solution was observed. Additionally, the photoactivity of 1% Pd-doped ZnO was tested under similar conditions to understand the effect of Pd doping on ZnO. Our results obtained under visible light irradiation are very promising, and they could be further explored for the degradation of several nondegradable environmental pollutants.

  15. Continuous on-line determination of methyl tert-butyl ether in water samples using ion mobility spectrometry.

    Science.gov (United States)

    Borsdorf, H; Rämmler, A

    2005-04-22

    A rapid analytical procedure for the on-line determination of methyl tert-butyl ether (MTBE) in water samples was developed. A new membrane extraction unit was used to extract the MTBE from water samples. The concentration of MTBE was determined using ion mobility spectrometry with 63Ni ionization and corona discharge ionization without chromatographic separation. Both ionization methods permit the sensitive determination of MTBE. A detection limit of 100 microg/L was established for the on-line procedure. Neither the inorganic compounds, humic substances nor gasoline were found to exert a significant influence on the peak intensity of the MTBE. The screening procedure can be used for concentrations of monoaromatic compounds (benzene, toluene, xylene) up to 600 microg/L. No sample preparation is required and the analysis results are available within 5 min. In order to determine concentrations between 10 microg/L and 100 microg/L, a discontinuous procedure was developed on the basis of the same experimental set-up.

  16. Health Risk Assessment for Inhalation Exposure to Methyl Tertiary Butyl Ether at Petrol Stations in Southern China

    Directory of Open Access Journals (Sweden)

    Dalin Hu

    2016-02-01

    Full Text Available Methyl tertiary butyl ether (MTBE, a well known gasoline additive, is used in China nationwide to enhance the octane number of gasoline and reduce harmful exhaust emissions, yet  little is known regarding the potential health risk associated with occupational exposure to MTBE in petrol stations. In this study, 97 petrol station attendants (PSAs in southern China were recruited for an assessment of the health risk associated with inhalation exposure to MTBE. The personal exposure levels of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS, and the demographic characteristics of the PSAs were investigated. Cancer and non-cancer risks were calculated with the methods recommended by the United States Environmental Protection Agency. The results showed that the exposure levels of MTBE in operating workers were much higher than among support staff (p < 0.01 and both were lower than 50 ppm (an occupational threshold limit value. The calculated cancer risks (CRs at the investigated petrol stations was 0.170 to 0.240 per 106 for operating workers, and 0.026 to 0.049 per 106 for support staff, which are below the typical target range for risk management of 1 × 10−6 to 1 × 10−4; The hazard quotients (HQs for all subjects were <1. In conclusion, our study indicates that the MTBE exposure of PSAs in southern China is in a low range which does not seem to be a significant health risk.

  17. Selective inhibition of ammonium oxidation and nitrification-linked N2O formation by methyl fluoride and dimethyl ether

    Science.gov (United States)

    Miller, L.G.; Coutlakis, M.D.; Oremland, R.S.; Ward, B.B.

    1993-01-01

    Methyl fluoride (CH3F) and dimethyl ether (DME) inhibited nitrification in washed-cell suspensions of Nitrosomonas europaea and in a variety of oxygenated soils and sediments. Headspace additions of CH3F (10% [vol/vol]) and DME (25% [vol/vol]) fully inhibited NO2- and N2O production from NH4+ in incubations of N. europaea, while lower concentrations of these gases resulted in partial inhibition. Oxidation of hydroxylamine (NH2OH) by N. europaea and oxidation of NO2- by a Nitrobacter sp. were unaffected by CH3F or DME. In nitrifying soils, CH3F and DME inhibited N2O production. In field experiments with surface flux chambers and intact cores, CH3F reduced the release of N2O from soils to the atmosphere by 20- to 30-fold. Inhibition by CH3F also resulted in decreased NO3- + NO2- levels and increased NH4+ levels in soils. CH3F did not affect patterns of dissimilatory nitrate reduction to ammonia in cell suspensions of a nitrate- respiring bacterium, nor did it affect N2O metabolism in denitrifying soils. CH3F and DME will be useful in discriminating N2O production via nitrification and denitrification when both processes occur and in decoupling these processes by blocking NO2- and NO3- production.

  18. Radiation-grafting of 2-hydroxyethylmethacrylate and oligo (ethylene glycol) methyl ether methacrylate onto polypropylene films by one step method

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Jimenez, Alejandro [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, Carmen; Concheiro, Angel [Departamento de Farmacia y Tecnologia Farmaceutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Bucio, Emilio, E-mail: ebucio@nucleares.unam.mx [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)

    2012-01-15

    Polypropylene films were modified with 2-hydroxyethylmethacrylate (HEMA) and oligo (ethylene glycol) methyl ether methacrylate (OEGMA) using the pre-irradiation method with gamma-rays (one step method). The effect of absorbed dose from 10 to 100 kGy, temperature (50, 60, and 70 {sup o}C), monomer concentration between 12.5% and 62.5%, monomers ratio from 10% to 90% and reaction time from 5 to 50 h; on the degree of grafting was determined. The grafted samples were analyzed by FTIR-ATR, TGA, DSC, swelling, and contact angle. Grafts onto polymeric films between 3% and 109% were obtained at doses from 10 to 100 kGy and a dose rate around 7.4 kGy/h. The graft percent increased with the content in HEMA in the HEMA:OEGMA feed mixture, which indicates a lower reactivity of OEGMA compared to HEMA. The hydrogel layer grafted on the polypropylene substrate increases the hydrophilicity of the surface and also provides certain temperature-responsiveness, which may be of interest for biomedical applications. - Highlights: > PP was grafted with a hydrogel layer applying the {gamma}-ray pre-irradiation method. > Effects of radiation dose, time, temperature and monomers concentration were evaluated. > Grafted layer increases the hydrophilicity of PP films. > HEMA and OEGMA grafted onto PP may be of interest for biomedical applications.

  19. The fungal phytotoxin alternariol 9-methyl ether and some of its synthetic analogues inhibit the photosynthetic electron transport chain.

    Science.gov (United States)

    Demuner, Antonio Jacinto; Barbosa, Luiz Cláudio Almeida; Miranda, Ana Cristina Mendes; Geraldo, Guilherme Carvalho; da Silva, Cleiton Moreira; Giberti, Samuele; Bertazzini, Michele; Forlani, Giuseppe

    2013-12-27

    Alternariol and monomethylalternariol are natural phytotoxins produced by some fungal strains, such as Nimbya and Alternaria. These substances confer virulence to phytopathogens, yet no information is available concerning their mode of action. Here we show that in the micromolar range alternariol 9-methyl ether is able to inhibit the electron transport chain (IC50 = 29.1 ± 6.5 μM) in isolated spinach chloroplasts. Since its effectiveness is limited by poor solubility in water, several alternariol analogues were synthesized using different aromatic aldehydes. The synthesized 6H-benzo[c]cromen-6-ones, 5H-chromene[4,3-b]pyridin-5-one, and 5H-chromene[4,3-c]pyridin-5-one also showed inhibitory properties, and three 6H-benzo[c]cromen-6-ones were more effective (IC50 = 12.8-22.8 μM) than the lead compound. Their addition to the culture medium of a cyanobacterial model strain was found to inhibit algal growth, with a relative effectiveness that was consistent with their activity in vitro. In contrast, the growth of a nonphotosynthetic plant cell culture was poorly affected. These compounds may represent a novel lead for the development of new active principles targeting photosynthesis.

  20. Enhanced cometabolic degradation of methyl tert-butyl ether by a Pseudomonas sp. strain grown on n-pentane

    Science.gov (United States)

    Li, S. S.; Wang, S.; Yan, W.

    2016-08-01

    When methyl tert-butyl ether (MTBE) is added as oxygenates it increases the octane number and decreases the release of nitric oxide from the incomplete combustion of reformulated gasoline. The extensive use of MTBE allowed it to be detectable as a pollutant in both ground-level and underground water worldwide. The present study focuses on the isolation and characterization of MTB-degrading microorganisms by cometabolism based on the results of growth on different carbon sources. It also focuses on the kinetic analysis and the continuous degradation of MTBE. A bacterial strain WL1 that can grow on both n-alkanes (C5-C8) and aromatics was isolated and named Pseudomonas sp. WL1 according to the 16S rDNA sequencing analysis. Strain WL1 could cometabolically degrade MTBE in the presence of n-alkanes with a desirable degradation rate. Diverse n-alkanes with different lengths of carbon chains showed significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When strain WL1 cometabolically degraded MTBE in the presence of n-pentane, higher MTBE-degrading rate and lower TBA-accumulation were observed (Vmax = 38.1 nmol/min/mgprotei, Ks = 6.8 mmol/L). In the continuous degrading experiment, the removal efficiency of MTBE by Pseudomonas sp. WL1 did not show any obvious decrease after five subsequent additions.

  1. 2D-Cell Experiment on Methyl Tert-Butyl Ether Transport in Saturated Zone of Groundwater

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an additive of gasoline, methyl tert-butyl ether (MTBE) has a higher solubility in water, which is about 20 times as high as that of benzene. This characteristic results in MTBE dissolving out of the gasoline into the soil and groundwater. Due to relative unique physicochemical behavior of MTBE it would be an ideal candidate for use in environmental forensic investigations. In order to study the transport and distribution of MTBE in saturated zone of ground water, a two-dimensional experimental cell was setup to simulate the real environment of the groundwater flow.The effects of soil and groundwater flow velocity on the MTBE transport were investigated. The results show that the mobile distance of MTBE in vertical direction was smaller than that in horizontal direction paralleling with the groundwater flow. Because the main dynamics of groundwater flow direction was convection and dispersion, the movement of MTBE is also diffusion in the vertical direction. In addition, the transport of MTBE was more quick in high permeability porous media, and the increase of groundwater flow velocity can accelerate the MTBE plume development, but the irregularity and randomness of the plume are enhanced synchronously. These research results can give some helps for the investigation of MTBE movement in the groundwater, also can make some references for other petroleum contamination behavior.

  2. 月桂酸氯甲酯的合成%Synthesis of Chloromethyl Dodecanoate

    Institute of Scientific and Technical Information of China (English)

    陈根花; 陈文斌; 朱英超

    2016-01-01

    月桂酸与固体三光气在DMF的引发下制得月桂酰氯,再与多聚甲醛、无水氯化锌,在二氯甲烷中于10℃下进行反应,即可制得较纯的月桂酸氯甲酯,总收率为95.0%,结构经气相色谱-质谱、核磁共振氢谱确证。该化合物是阿德福韦双月桂酰氧甲酯的重要中间体。%Chloromethyl dodecanoate, the key intermediate of adefovir dilauroyl oxygen methyl ester, was synthesized from lauric acid. Lauroyl chloride, which was prepared by the reaction of lauric acid and bis (trichloromethyl) carbonate (BTC) in the presence of DMF, reacted with paraformaldehyde in DCM under the catalysis of zinc chloride to provide chloromethyl dodecanoate. The overall yield was up to 95.0% and the structure of the target compound was confirmed by 1HNMR and GC-MS.

  3. The interactions of methyl tert-butyl ether on high silica zeolites: a combined experimental and computational study.

    Science.gov (United States)

    Sacchetto, V; Gatti, G; Paul, G; Braschi, I; Berlier, G; Cossi, M; Marchese, L; Bagatin, R; Bisio, C

    2013-08-28

    In this work, the interactions of methyl tert-butyl ether (MTBE) on different dealuminated high silica zeolites were studied by means of both experimental and computational approaches. Zeolites with different textural and surface features were selected as adsorbents and the effect of their physico-chemical properties (i.e. pore size architecture and type and amount of surface OH sites) on sorption capacity were studied. High silica mordenite (MOR) and Y zeolites (both with a SiO2/Al2O3 ratio of 200) and ZSM-5 solid (SiO2/Al2O3 ratio of 500) were selected as model sorbents. By combining FTIR and SS-NMR (both (1)H and (13)C CPMAS NMR) spectroscopy it was possible to follow accurately the MTBE adsorption process on highly defective MOR characterized by a high concentration of surface SiOH groups. The adsorption process is found to occur in different steps and to involve isolated silanol sites, weakly interacting silanols, and the siloxane network of the zeolite, respectively. H-bonding and van der Waals interactions occurring between the mordenite surface and MTBE molecules were modeled by DFT calculations using a large cluster of the MOR structure where two adjacent side-pockets were fused in a large micropore to simulate a dealumination process leading to silanol groups. This is the locus where MTBE molecules are more strongly bound and stabilized. FTIR spectroscopy and gravimetric measurements allowed determination of the interaction strength and sorption capacities of all three zeolites. In the case of both Y and MOR zeolites, medium-weak H-bonding with isolated silanols (both on internal and external zeolite surfaces) and van der Waals interactions are responsible for MTBE adsorption, whereas ZSM-5, in which a negligible amount of surface silanol species is present, displays a much lower amount of adsorbed MTBE retained mainly through van der Waals interactions with zeolite siloxane network.

  4. Exposure to methyl tert-butyl ether, benzene, and total hydrocarbons at the Singapore-Malaysia causeway immigration checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.; Ong, H.Y.; Kok, P.W. [and others

    1996-12-31

    The primary aim of this study was to determine the extent and levels of exposure to volatile organic compounds (VOCs) from automobile emissions in a group of immigration officers at a busy cross-border checkpoint. A majority (80%) of the workers monitored were exposed to benzene at levels between 0.01 and 0.5 ppm, with only 1.2% exceeding the current Occupational Safety and Health Administration occupational exposure limit of 1 ppm. The geometric mean (GM) concentrations of 8-hr time-weighted average exposure were 0.03 ppm, 0.9 ppm, and 2.46 ppm for methyl-tert-butyl ether (MTBE), benzene, and total hydrocarbons (THC), respectively. The highest time-weighted average concentrations measured were 1.05 ppm for MTBE, 2.01 ppm for benzene, and 34 ppm for THC. It was found that motorbikes emitted a more significant amount of pollutants compared with motor cars. On average, officers at the motorcycle booths were exposed to four to five times higher levels of VOCs (GMs of 0.07 ppm, 0.23 ppm, and 4.7 ppm for MTBE, benzene, and THC) than their counterparts at the motor car booths (GMs of 0.01 ppm, 0.05 ppm, and 1.5 ppm). The airborne concentrations of all three pollutants correlated with the flow of vehicle traffic. Close correlations were also noted for the concentrations in ambient air for the three pollutants measured. Benzene and MTBE had a correlation coefficient of 0.97. The overall findings showed that the concentrations of various VOCs were closely related to the traffic density, suggesting that they were from a common source, such as exhaust emissions from the vehicles. The results also indicated that although benzene, MTBE, and THC are known to be volatile, a significant amount could still be detected in the ambient environment, thus contributing to our exposure to these compounds. 4 refs., 6 figs.

  5. Chronic carcinogenicity study of gasoline vapor condensate (GVC) and GVC containing methyl tertiary-butyl ether in F344 rats.

    Science.gov (United States)

    Benson, Janet M; Gigliotti, Andrew P; March, Thomas H; Barr, Edward B; Tibbetts, Brad M; Skipper, Betty J; Clark, Charles R; Twerdok, Lorraine

    2011-01-01

    Chronic inhalation studies were conducted to compare the toxicity and potential carcinogenicity of evaporative emissions from unleaded gasoline (GVC) and gasoline containing the oxygenate methyl tertiary-butyl ether (MTBE; GMVC). The test materials were manufactured to mimic vapors people would be exposed to during refueling at gas stations. Fifty F344 rats per gender per exposure level per test article were exposed 6 h/d, 5 d/wk for 104 wk in whole body chambers. Target total vapor concentrations were 0, 2, 10, or 20 g/m³ for the control, low-, mid-, and high-level exposures, respectively. Endpoints included survival, body weights, clinical observations, organs weights, and histopathology. GVC and GMVC exerted no marked effects on survival or clinical observations and few effects on organ weights. Terminal body weights were reduced in all mid- and high-level GVC groups and high-level GMVC groups. The major proliferative lesions attributable to gasoline exposure with or without MTBE were renal tubule adenomas and carcinomas in male rats. GMV exposure led to elevated testicular mesothelioma incidence and an increased trend for thyroid carcinomas in males. GVMC inhalation caused an increased trend for testicular tumors with exposure concentration. Mid- and high-level exposures of GVC and GMVC led to elevated incidences of nasal respiratory epithelial degeneration. Overall, in these chronic studies conducted under identical conditions, the health effects in F344 rats following 2 yr of GVC or GMVC exposure were comparable in the production of renal adenomas and carcinomas in male rats and similar in other endpoints.

  6. Characteristics of Nonafluorobutyl Methyl Ether (NFE) Adsorption onto Activated Carbon Fibers and Different-Size-Activated Carbon Particles.

    Science.gov (United States)

    Tanada; Kawasaki; Nakamura; Araki; Tachibana

    2000-08-15

    The characteristics of adsorption of 1,1,1,2,2,3,3,4,4-nonafluorobutyl methyl ether (NFE), a chlorofluorocarbon (CFC) replacement, onto six different activated carbon; preparations (three activated carbon fibers and three different-sized activated carbon particles) were investigated to evaluate the interaction between activated carbon surfaces and NFE. The amount of NFE adsorbed onto the three activated carbon fibers increased with increasing specific surface area and pore volume. The amount of NFE adsorbed onto the three different-sized-activated carbon particles increased with an increase in the particle diameter of the granular activated carbon. The differential heat of the NFE adsorption onto three activated carbon fibers depended on the porosity structure of the activated carbon fibers. The adsorption rate of NFE was also investigated in order to evaluate the efficiency of NFE recovery by the activated carbon surface. The Sameshima equation was used to obtain the isotherms of NFE adsorption onto the activated carbon fibers and different-sized-activated carbon particles. The rate constant k for NFE adsorption onto activated carbon fibers was larger for increased specific surface area and pore volume. The rate of NFE adsorption on activated carbons of three different particle sizes decreased with increasing particle diameter at a low initial pressure. The adsorption isotherms of NFE for the six activated carbons conformed to the Dubinin-Radushkevich equation; the constants BE(0) (the affinity between adsorbate and adsorbent) and W(0) (the adsorption capacity) were calculated. These results indicated that the interaction between the activated carbon and NFE was larger with the smaller specific surface area of the activated carbon fibers and with the smaller particle diameter of the different-sized-activated carbon particles. The degree of packing of NFE in the pores of the activated carbon fibers was greater than that in the pores of the granular activated

  7. Thermodynamic properties (enthalpy, bond energy, entropy, and heat capacity) and internal rotor potentials of vinyl alcohol, methyl vinyl ether, and their corresponding radicals.

    Science.gov (United States)

    da Silva, Gabriel; Kim, Chol-Han; Bozzelli, Joseph W

    2006-06-29

    Vinyl alcohols (enols) have been discovered as important intermediates and products in the oxidation and combustion of hydrocarbons, while methyl vinyl ethers are also thought to occur as important combustion intermediates. Vinyl alcohol has been detected in interstellar media, while poly(vinyl alcohol) and poly(methyl vinyl ether) are common polymers. The thermochemical property data on these vinyl alcohols and methyl vinyl ethers is important for understanding their stability, reaction paths, and kinetics in atmospheric and thermal hydrocarbon-oxygen systems. Enthalpies , entropies , and heat capacities (C(p)()(T)) are determined for CH(2)=CHOH, C(*)H=CHOH, CH(2)=C(*)OH, CH(2)=CHOCH(3), C(*)H=CHOCH(3), CH(2)=C(*)OCH(3), and CH(2)=CHOC(*)H(2). Molecular structures, vibrational frequencies, , and C(p)(T) are calculated at the B3LYP/6-31G(d,p) density functional calculation level. Enthalpies are also determined using the composite CBS-Q, CBS-APNO, and G3 methods using isodesmic work reactions to minimize calculation errors. Potential barriers for internal rotors are calculated at the B3LYP/6-31G(d,p) level and used to determine the hindered internal rotational contributions to entropy and heat capacity. The recommended ideal gas phase values calculated in this study are the following (in kcal mol(-1)): -30.0, -28.9 (syn, anti) for CH(2)=CHOH; -25.6, -23.9 for CH(2)=CHOCH(3); 31.3, 33.5 for C(*)H=CHOH; 27.1 for anti-CH(2)=C(*)OH; 35.6, 39.3 for C(*)H=CHOCH(3); 33.5, 32.2 for CH(2)=C(*)OCH(3); 21.3, 22.0 for CH(2)=CHOC(*)H(2). Bond dissociation energies (BDEs) and group additivity contributions are also determined. The BDEs reveal that the O-H, O-CH(3), C-OH, and C-OCH(3) bonds in vinyl alcohol and methyl vinyl ether are similar in energy to those in the aromatic molecules phenol and methyl phenyl ether, being on average around 3 kcal mol(-1) weaker in the vinyl systems. The keto-enol tautomerization enthalpy for the interconversion of vinyl alcohol to acetaldehyde is

  8. Using physiologically based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.

    Energy Technology Data Exchange (ETDEWEB)

    Kirman, C R.; Sweeney, Lisa M.; Corley, Rick A.; Gargas, M L.

    2005-04-01

    Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based upon transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues was selected as the most appropriate internal dose measure based upon a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based upon the presence or absence of sedation at each time-point, species, and sex in the two year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of ten. Nonlinear kinetics are were predicted by the model in all species at PGME concentrations exceeding 100 ppm, which complicates interspecies and low-dose extrapolations. To address this complication, reference values were derived using two approaches which differ with respect to the order in which these extrapolations

  9. Synthesis and Properties of the Metallo-Supramolecular Polymer Hydrogel Poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3

    KAUST Repository

    Al-Dossary, Mona S.

    2014-05-01

    Gels are a special class of materials which are composed of 3D networks of crosslinked polymer chains that encapsulate liquid/air in the matrix. They can be classified into organogels or hydrogels (organic solvent for organogel and water for hydrogel). For hydrogels that contain metallic elements in the form of ions, the term of metallo-supramolecular polymer hydrogel (MSPHG) is often used. The aim of this project is to develop a kind of new MSPHG and investigate its properties and possible applications. The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-monosodium maleate) (PVM/Na-MA). By addition of AgNO3-solution, the formation of the silver(I) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]∙AgNO3 is obtained. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(I) cations. The supercritical CO2 dried silver(I) hydrogel was characterized by FT-IR, SEM-EDAX, TEM, TGA and Physical adsorption (BET) measurements. The intact silver(I) hydrogel was characterized by cryo-SEM. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(II) cations without disintegration of the hydrogel. The silver(I) hydrogel shows effective antibacterial activity and potential application as burn wound dressing.

  10. Preparation of Anion Exchange Membrane Based on Imidazolium Functionalized Poly(arylene ether ketone)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hao; ZHANG Na; MA Wen-jia; ZHAO Cheng-ji; NA Hui

    2013-01-01

    The authors presented a novel synthetic route for the imidazolium functionalized poly(arylene ether ketone)s,derived from an engineering plastics polymer,a poly(arylene ether ketone) with 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl moiety(PAEK-TM).The preparation of anion exchange membranes comprised converting benzylic methyl groups to bromomethyl groups by a radical reaction,followed by the functionalization of bromomethylated PAEK with alkyl imidazoles,i.e.,methyl,butyl or vinyl imidazole.The structure of imidazolium functionalized PAEK was proved by 1H NMR spectra.A class of flexible and tough membranes was then achieved by subsequent film-forming and anion exchange processes.The water uptake and hydroxide conductivities of membranes are comparable or superior to those of quaternary ammonium(QA) anion exchange membranes.This work demonstrated a new route for non-QA anion exchange membrane design,avoiding the chloromethylation reagent and precisely controlling the degree and location of imidazolium groups.

  11. Excess enthalpy, density, and speed of sound determination for the ternary mixture (methyl tert-butyl ether + 1-butanol + n-hexane)

    Energy Technology Data Exchange (ETDEWEB)

    Mascato, Eva [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain); Mariano, Alejandra [Laboratorio de Fisicoquimica, Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, 8300 Neuquen (Argentina); Pineiro, Manuel M. [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain)], E-mail: mmpineiro@uvigo.es; Legido, Jose Luis [Departamento de Fisica Aplicada, Facultade de Ciencias, Universidade de Vigo, E-36310 Vigo (Spain); Paz Andrade, M.I. [Departamento de Fisica Aplicada, Facultade de Fisica, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela (Spain)

    2007-09-15

    Density, ({rho}), and speed of sound, (u), from T = 288.15 to T = 308.15 K, and excess molar enthalpies, (h{sup E}) at T = 298.15 K, have been measured over the entire composition range for (methyl tert-butyl ether + 1-butanol + n-hexane). In addition, excess molar volumes, V{sup E}, and excess isentropic compressibility, {kappa}{sub s}{sup E}, were calculated from experimental data. Finally, experimental excess enthalpies results are compared with the estimations obtained by applying the group-contribution models of UNIFAC (in the versions of Dang and Tassios, Larsen et al., Gmehling et al.), and DISQUAC.

  12. Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1511, LB4833_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1511, LB4833_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  13. Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1212, LB4828_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1212, LB4828_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1111, LB4823_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Cyclohexanone C6H10O + C7H8O Methyl phenyl ether (VMSD1111, LB4823_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Determination of methyl tert-butyl ether (MTBE) in Chinese fuels by gas chromatography/mass spectrometry and gas chromatography/flame ionization detector

    Institute of Scientific and Technical Information of China (English)

    LIU Jie-min; CHENG Wei; WEN Mei-juan; JIANG Gui-bin

    2004-01-01

    A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline,diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection (FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.

  16. Microwave assisted synthesis of a small library of substituted N,N'-bis((8-hydroxy-7-quinolinyl)methyl)-1,10-diaza-18-crown-6 ethers.

    Science.gov (United States)

    Farruggia, Giovanna; Iotti, Stefano; Lombardo, Marco; Marraccini, Chiara; Petruzziello, Diego; Prodi, Luca; Sgarzi, Massimo; Trombini, Claudio; Zaccheroni, Nelsi

    2010-09-17

    N,N'-bis-((8-hydroxy-7-quinolinyl)methyl)-1,10-diaza-18-crown-6 ether 1a and its analogue 1c are known as fluorescent sensors of magnesium in living cells. With the aim to investigate the effects of the substitution pattern on the photophysical properties of ligands 1 and their metal complexes, we developed an efficient microwaves enhanced one-pot Mannich reaction to double-armed diaza-crown ligands 1 carrying a variety of substituents. This new protocol is characterized by shorter reaction times, enhanced yields, and improved product purities with respect to the use of conventional conductive heating.

  17. Manipulation of the HIF–Vegf pathway rescues methyl tert-butyl ether (MTBE)-induced vascular lesions

    Energy Technology Data Exchange (ETDEWEB)

    Bonventre, Josephine A., E-mail: josephine.bonventre@oregonstate.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); Oregon State University, Department of Environmental and Molecular Toxicology, 1011 Agricultural and Life Sciences Bldg, Corvallis, OR 97331 (United States); Kung, Tiffany S., E-mail: tiffany.kung@rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); White, Lori A., E-mail: lawhite@aesop.rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States); Cooper, Keith R., E-mail: cooper@aesop.rutgers.edu [Rutgers, The State University of New Jersey, Joint Graduate Program in Toxicology, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Rutgers, The State University of New Jersey, Department of Biochemistry and Microbiology, 76 Lipman Dr., New Brunswick, NJ 08901 (United States)

    2013-12-15

    Methyl tert-butyl ether (MTBE) has been shown to be specifically anti-angiogenic in piscine and mammalian model systems at concentrations that appear non-toxic in other organ systems. The mechanism by which MTBE targets developing vascular structures is unknown. A global transcriptome analysis of zebrafish embryos developmentally exposed to 0.00625–5 mM MTBE suggested that hypoxia inducible factor (HIF)-regulated pathways were affected. HIF-driven angiogenesis via vascular endothelial growth factor (vegf) is essential to the developing vasculature of an embryo. Three rescue studies were designed to rescue MTBE-induced vascular lesions: pooled blood in the common cardinal vein (CCV), cranial hemorrhages (CH), and abnormal intersegmental vessels (ISV), and test the hypothesis that MTBE toxicity was HIF–Vegf dependent. First, zebrafish vegf-a over-expression via plasmid injection, resulted in significantly fewer CH and ISV lesions, 46 and 35% respectively, in embryos exposed to 10 mM MTBE. Then HIF degradation was inhibited in two ways. Chemical rescue by N-oxaloylglycine significantly reduced CCV and CH lesions by 30 and 32% in 10 mM exposed embryos, and ISV lesions were reduced 24% in 5 mM exposed zebrafish. Finally, a morpholino designed to knock-down ubiquitin associated von Hippel–Lindau protein, significantly reduced CCV lesions by 35% in 10 mM exposed embryos. In addition, expression of some angiogenesis related genes altered by MTBE exposure were rescued. These studies demonstrated that MTBE vascular toxicity is mediated by a down regulation of HIF–Vegf driven angiogenesis. The selective toxicity of MTBE toward developing vasculature makes it a potentially useful chemical in the designing of new drugs or in elucidating roles for specific angiogenic proteins in future studies of vascular development. - Highlights: • Global gene expression of MTBE exposed zebrafish suggested altered HIF1 signaling. • Over expression of zebrafish vegf-a rescues MTBE

  18. Hydrolysis of tert-butyl formate: Kinetics, products, and implications for the environmental impact of methyl tert-butyl ether

    Science.gov (United States)

    Church, Clinton D.; Pankow, James F.; Tratnyek, Paul G.

    1999-01-01

    Asessing the environmental fate of methyl tert-butyl ether (MTBE) has become a subject of renewed interest because of the large quantities of this compound that are being used as an oxygenated additive in gasoline. Various studies on the fate of MTBE have shown that it can be degraded to tert-butyl formate (TBF), particularly in the atmosphere. Although it is generally recognized that TBF is subject to hydrolysis, the kinetics and products of this reaction under environmentally relevant conditions have not been described previously. In this study, we determined the kinetics of TBF hydrolysis as a function of pH and temperature. Over the pH range of 5 to 7, the neutral hydrolysis pathway predominates, with kN = (1.0 ± 0.2) × 10−6/s. Outside this range, strong pH effects were observed because of acidic and basic hydrolyses, from which we determined that kA = (2.7 ± 0.5) × 10−3/(M·s) and kB = 1.7 ± 0.3/(M·s). Buffered and unbuffered systems gave the same hydrolysis rates for a given pH, indicating that buffer catalysis was not significant under the conditions tested. The activation energies corresponding to kN, kA, and kBwere determined to be 78 ± 5, 59 ± 4, and 88 ±11 kJ/mol, respectively. In all experiments, tert-butyl alcohol was found at concentrations corresponding to stoichiometric formation from TBF. Based on our kinetics data, the expected half-life for hydrolysis of TBF at pH = 2 and 4°C (as per some standard preservation protocols for water sampling) is 6 h. At neutral pH and 22°C, the estimated half-life is 5 d, and at pH = 11 and 22°C, the value is only 8 min.

  19. Synthesis and properties of the metallo-supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO3: Ag+/Cu2+ ion exchange and effective antibacterial activity

    KAUST Repository

    Xu, Feng

    2014-01-01

    The commercial polymeric anhydride poly(methyl vinyl ether-alt-maleic anhydride) (PVM/MA) is converted by reaction with NaOH to give poly(methyl vinyl ether-alt-mono-sodium maleate) (PVM/Na-MA). By addition of AgNO 3-solution, the formation of the silver(i) supramolecular polymer hydrogel poly[methyl vinyl ether-alt-mono-sodium maleate]·AgNO 3 is reported. Freeze-dried samples of the hydrogel show a mesoporous network of polycarboxylate ligands that are crosslinked by silver(i) cations. In the intact hydrogel, ion-exchange studies are reported and it is shown that Ag+ ions can be exchanged by copper(ii) cations without disintegration of the hydrogel. The silver(i) hydrogel shows effective antibacterial activity and potential application as burn wound dressing. © the Partner Organisations 2014.

  20. (Liquid + liquid) and (liquid + solid) equilibrium of aqueous two-phase systems containing poly ethylene glycol di-methyl ether 2000 and di-sodium hydrogen phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zafarani-Moattar, Mohammed Taghi, E-mail: zafarani47@yahoo.co [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Nasiri, Saeed [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

    2010-09-15

    (Liquid + liquid) equilibrium (LLE) for the {l_brace}poly ethylene glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system have been determined experimentally at T = (298.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS) have been studied. An empirical non-linear expression developed by Merchuk was used for reproducing the experimental binodal data. In this work, the three fitting parameters of the Merchuk equation were obtained with the temperature dependence expressed in the linear form with (T - T{sub 0}) K as a variable. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used to describe the LLE data of the studied system. Also, the effects of the type of salt on LLE are discussed. In addition, the effects of end groups of the polymers PEGDME{sub 2000} and poly ethylene glycol 2000 on phase forming ability were studied. The complete phase diagram for the poly ethylene {l_brace}glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system has also been determined at T = 298.15 K.

  1. Intramolecular CH⋯π and CH⋯O interactions in the conformational stability of benzyl methyl ether studied by matrix-isolation infrared spectroscopy and theoretical calculations

    Science.gov (United States)

    Shin-ya, Kei; Takahashi, Osamu; Katsumoto, Yukiteru; Ohno, Keiichi

    2007-02-01

    Contributions of the intramolecular CH⋯π and CH⋯O interactions to the molecular conformation of benzyl methyl ether (BME) have been investigated by matrix-isolation infrared (IR) spectroscopy combined with quantum chemical calculations. Comparative investigations have been carried out for propylbenzene. Quantum chemical calculations predict that there are two conformers for BME; for the ET conformer the methyl ether and the phenyl groups lie in the plane of the benzene ring, while for the AG conformer they are out of the plane. Comparison between the observed and calculated spectra for BME reveals that the ET and AG conformers coexist in an Ar matrix. By measuring matrix-isolation IR spectra of BME deposited at different gas temperatures, the enthalpy difference (Δ H (AG - ET)) between ET and AG conformers was determined to be -1.03 ± 0.06 kJ mol -1. The experimental and calculation results indicate that the AG conformer of BME is stabilized by the intramolecular CH⋯π and CH⋯O interactions.

  2. Oxidation of methyl tert-butyl ether by alkane hydroxylase in dicyclopropylketone-induced and n-octane-grown Pseudomonas putida GPo1.

    Science.gov (United States)

    Smith, Christy A; Hyman, Michael R

    2004-08-01

    The alkane hydroxylase enzyme system in Pseudomonas putida GPo1 has previously been reported to be unreactive toward the gasoline oxygenate methyl tert-butyl ether (MTBE). We have reexamined this finding by using cells of strain GPo1 grown in rich medium containing dicyclopropylketone (DCPK), a potent gratuitous inducer of alkane hydroxylase activity. Cells grown with DCPK oxidized MTBE and generated stoichiometric quantities of tert-butyl alcohol (TBA). Cells grown in the presence of DCPK also oxidized tert-amyl methyl ether but did not appear to oxidize either TBA, ethyl tert-butyl ether, or tert-amyl alcohol. Evidence linking MTBE oxidation to alkane hydroxylase activity was obtained through several approaches. First, no TBA production from MTBE was observed with cells of strain GPo1 grown on rich medium without DCPK. Second, no TBA production from MTBE was observed in DCPK-treated cells of P. putida GPo12, a strain that lacks the alkane-hydroxylase-encoding OCT plasmid. Third, all n-alkanes that support the growth of strain GPo1 inhibited MTBE oxidation by DCPK-treated cells. Fourth, two non-growth-supporting n-alkanes (propane and n-butane) inhibited MTBE oxidation in a saturable, concentration-dependent process. Fifth, 1,7-octadiyne, a putative mechanism-based inactivator of alkane hydroxylase, fully inhibited TBA production from MTBE. Sixth, MTBE-oxidizing activity was also observed in n-octane-grown cells. Kinetic studies with strain GPo1 grown on n-octane or rich medium with DCPK suggest that MTBE-oxidizing activity may have previously gone undetected in n-octane-grown cells because of the unusually high K(s) value (20 to 40 mM) for MTBE.

  3. Determination of the Solubility of Phenyl Ether Methyl Nitrate%苯醚甲环唑硝酸盐溶解度的测定

    Institute of Scientific and Technical Information of China (English)

    袁军

    2016-01-01

    the phenyl ether is a kind of commonly used fungicide.In the process of refining the crude product,it is necessary to add excessive concentrated nitric acid into salt,and then add alkali to restore,but there is a lot of benzyl ether in the waste.In order to improve the production process,the solubility of phenyl ether methyl nitrate in the two solvents of toluene/nitric acid was determined in this paper.The experimental results show that the main reason for the low yield of benzene ether is the excess of nitric acid,and the use of nitric acid should be paid attention to during the process of technological improvement.%苯醚甲环唑是一种常用杀菌剂。现行工艺粗品提纯过程中需加入过量浓硝酸成盐,再加碱还原,但是废料中存在大量苯醚甲环唑,总产率较低。为改进生产工艺,测定了苯醚甲环唑硝酸盐在甲苯/硝酸二元溶剂中的溶解度。实验结果表明硝酸过量是苯醚甲环唑产率低的主要原因,在今后的工艺改进过程中,应注意硝酸的使用。

  4. 微波辐射下固相反应合成二苯基甲基醚%Synthesis of Bis(diphenyl methyl)ether by Dry Reaction under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    路建美; 纪顺俊; 朱秀林; 程振平

    2000-01-01

    Bis(diphenyl methyl)ether was synthesized under microwave irradiation by dryreaction at ambient pressure. The rate of reaction was dramatically accelerated and high yield was obtained, comparing with that of methods using organic solvent as medium or using dry reaction by conventional heating. Keywords Diphenyl ketone, Bis (diphenyl methyl) ether, Microwave irradiation, Solid state.%在常压下用微波辐射固相反应的方法合成了二苯基甲基醚,与用有机溶剂为介质及传统的热固相反应方法相比,其反应速率快,产率高.

  5. The Chloromethylation of a Phenolphthalein Polyetherketone Resin%无定型酚酞聚芳醚酮的氯甲基化改性

    Institute of Scientific and Technical Information of China (English)

    贾宝珠; 王红华; 崔善子; 周光远

    2011-01-01

    A detailed research on the chloromethylation process was carried out. The chloromethylation of a phenolphthalein polyetherketone resin(PEK-C) was performed in a homogeneous reaction system using 1,4-bis (chloromethoxyl) butane as the chloromethylation reagent and concentrated sulforic acid as the solvent and catalyst. This method is environmentally friendly because of the absence of cancerogenic toxicity of BCMB. Furthermore, this method is more economical because of the low cost of BCMB. The effects of various factors on the chloromethylations were examined. The chemical structure and composition of the chloromethyled phenolphthalein polyetherketone resin ( CMPEK-C ) were characterized by Fourier transform infrared spectroscopy(FT-IR) and nuclear magnetic resonance('H NMR). The experimental results show that the reaction mechanism consists of two kinds of reactions including electrophilic substitution on benzene ring and nucleophilic substitution accompanying by ether linkage fissiond. During the process in preparing CMPEK-C, along with the increase of chlorine content, Friedel-Crafts crosslinking reaction will occur. To prepare the chloromethylated PEK-C with high chlorine content and without obvious cross-linking, the suitable reaction conditions, such as reaction time, temperature influence and the used amount of 1,4-bis ( chloromethoxy) butane (BCMB), need to be controlled. The reaction should be carried out at lower temperatures (about 10 ~ 30 t) because of the sensitivity of Friedel-Crafts reaction to temperature. Namely, there are two types of effects of reaction conditions on the chloromethylation of PEK-C, one is the influence on PEK-C chloromethylation degree, and the other is the influence on the remaining linearity for PEK-C. The CMPEK-C with 3.4 of chloromethylation degree and complete linearity was obtained under the optimized reaction conditions. The properties of CMPEK-C such as solubility in common organic solvents and thermal stability compared

  6. The Synthesis and Properties of Soluble Poly(Aryl Ether Sulfone Ether Ketone) Containing Pendent Methyl Groups%可溶性甲基取代聚芳醚砜醚酮的合成与性能

    Institute of Scientific and Technical Information of China (English)

    刘烨; 高兴; 钟鸣; 黄志强; 宋琤; 宋才生

    2011-01-01

    A series of poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis(l,4-phenylene)dioxy]dibenzoyl chloride with 4,4'-diphenoxy diphenylsulfone (DPODPS), 4,4'-di(2-methylphenoxy)diphenylsulfone(o-Me-DPODPS), 4,4'-di(3-methylphenoxy) diphenylsulfone (m-Me-DPODPS), 4,4'-di(2,6-bimethylphenoxy) biphenylsulfone(o-Me2-DPODPS) respectively, in a mixture of l,2-dichloroethane(DCE) and A/-methylpyrrolidone (NMP). These reactions were catalyzed by anhydrous aluminum chloride (A1C13). The charac teristic of copolymers were studied by means of advanced analytical techniques such as FT-IR, 1H NMR, DSC, TGA and WAXD.The results show that glass transition temperature (Tg) in the range of 193-206℃, thermally stable in excess of 434 ℃ and excellent solubility in polar solvents.Methyl-substituted poly(aryl ether sulfone ketone)s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones.%以4,4′-二(4-氯甲酰基苯氧基)二苯砜(SODBC)与4,4′-二苯氧基二苯砜(DPODPS)、4,4′-二(2-甲基苯氧基)二苯砜(o-Me-DPODPS)、4,4′-二(3-甲基苯氧基)二苯砜(m-Me-DPODPS)和4,4′-二(2,6-二甲基苯氧基)二苯砜(o-Me2-DPODPS)等为单体在1,2-二氯乙烷(DCE)、N-2-甲基吡咯烷酮(NMP)、无水三氯化铝(AlCl3)溶剂催化剂体系中,通过低温溶液亲电共缩聚合成了聚芳醚砜醚酮(PESEK),邻位、间位甲基取代、双邻位甲基取代的聚芳醚砜醚酮(o-Me-PESEK、m-Me-PESEK、o-Me2-PESEK)聚合物.用FT-IR、1H NMR、DSC、TGA、WAXD等对聚合物进行了表征,研究了聚合物的溶解性.结果表明:聚合物具有较高的玻璃化转变温度(Tg)、良好的执稳定性和优良的溶解性.

  7. 丙酮肟甲醚饱和蒸气压测定及关联%Vapor Pressure Measurement and Correlation of Acetone Oxime Methyl Ether

    Institute of Scientific and Technical Information of China (English)

    叶长燊; 董佳; 李玲

    2013-01-01

      采用动态法,利用Rose釜测定了丙酮肟甲醚在307.75~344.05 K的饱和蒸气压,并应用Antoine方程进行关联,获得Antoine常数A、B、C分别为20.64,2338.72和−88.86,Antoine方程计算值与饱和蒸气压实验测定值之间的平均相对误差为0.45%.在此基础上,通过Clausius-Clapeyron方程计算得到丙酮肟甲醚在307.75~344.05 K温度范围内的平均摩尔蒸发热为36479.24 kJ⋅kmol−1.所得饱和蒸气压方程对丙酮肟甲醚精馏分离过程的设计与操作具有重要意义.%Saturated vapor pressures of acetone oxime methyl ether(AOME) were measured in the temperature range of 307.75~344.05 K by dynamic method in a Rose still. The measured saturated vapor pressures and temperatures were correlated by Antoine equation and the constants of equation were determinated as A=20.64, B = 2338.72, and C = −88.86 by nonlinear regression method. The averaged relative error between saturated vapor pressures calculated from the Antoine equation and the experimental data is 0.45%. Based on the experimental data of vapor pressures, the latent heat of vaporization of acetone oxime methyl ether was also obtained by Clausius-Clapeyron equation and its value is 36479.24 kJ⋅kmol−1 in the temperature range of 307.75~344.05 K. It is very important to provide the Antoine constants and latent heat of acetone oxime methyl ether for the design and operation of its distillation separation process.

  8. A new multifunctional initiator system for the living cationic polymerization of vinyl ethers

    NARCIS (Netherlands)

    Zhang, Xiaochun; Goethals, Eric J.; Loontjens, Ton; Derks, Frank

    2000-01-01

    Combination of hexa(chloromethyl)melamine (HCMM) and zinc chloride was found to be a multifunctional initiator system for the living cationic polymerization of isobutyl vinyl ether. HCMM was synthesized by reaction of hexa(methoxymethyl)melamine and boron trichloride. Characterization of the polymer

  9. 21 CFR 173.70 - Chloromethylated aminated styrene-divinylbenzene resin.

    Science.gov (United States)

    2010-04-01

    ... resin. 173.70 Section 173.70 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Chloromethylated aminated styrene-divinylbenzene resin. Chloromethylated aminated styrene-divinylbenzene copolymer... resin dispersion. (c) The additive is used as a decolorizing and clarification agent for treatment...

  10. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the safety of ―Methyl Vinyl Ether-Maleic Anhydride Copolymer‖ (chewing gum base ingredient) as a Novel Food ingredient

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the safety of “methyl vinyl ether-maleic anhydride copolymer (Gantrez SF)” as a novel food ingredient in the context of Regulation (EC)...... concerns regarding genotoxicity and the low molecular weight components. The Panel concludes that the novel food ingredient, methyl vinyl ether-maleic anhydride copolymer (Gantrez SF), is safe under the proposed uses and use levels.......Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the safety of “methyl vinyl ether-maleic anhydride copolymer (Gantrez SF)” as a novel food ingredient in the context of Regulation (EC......) No 258/97. The novel food ingredient Gantrez SF is an anhydrous copolymer formed by the reaction of methyl vinyl ether (MVE) and maleic anhydride (MAN) under appropriate conditions. The Panel considers that the information provided on the specifications, stability and production process do not raise...

  11. Atomic motions in poly(vinyl methyl ether): A combined study by quasielastic neutron scattering and molecular dynamics simulations in the light of the mode coupling theory.

    Science.gov (United States)

    Capponi, S; Arbe, A; Alvarez, F; Colmenero, J; Frick, B; Embs, J P

    2009-11-28

    Quasielastic neutron scattering experiments (time-of-flight, neutron spin echo, and backscattering) on protonated poly(vinyl methyl ether) (PVME) have revealed the hydrogen dynamics above the glass-transition temperature. Fully atomistic molecular dynamics simulations properly validated with the neutron scattering results have allowed further characterization of the atomic motions accessing the correlation functions directly in real space. Deviations from Gaussian behavior are found in the high-momentum transfer range, which are compatible with the predictions of mode coupling theory (MCT). We have applied the MCT phenomenological version to the self-correlation functions of PVME atoms calculated from our simulation data, obtaining consistent results. The unusually large value found for the lambda-exponent parameter is close to that recently reported for polybutadiene and simple polymer models with intramolecular barriers.

  12. The Formation of Polycomplexes of Poly(Methyl Vinyl Ether-Co-Maleic Anhydride and Bovine Serum Albumin in the Presence of Copper Ions

    Directory of Open Access Journals (Sweden)

    Karahan Mesut

    2014-09-01

    Full Text Available The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride (PMVEMA with copper ions and with bovine serum albumin (BSA in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II, the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.

  13. 40 CFR 721.5560 - Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz[c...

    Science.gov (United States)

    2010-07-01

    ... (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz oxaphosphorin-6-oxide. 721.5560 Section 721... Formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with 6H-dibenz oxaphosphorin-6... identified as formaldehyde, polymer with (chloromethyl) oxirane and phenol, reaction products with...

  14. Metabolic Profiling of the Uncaria Hook Alkaloid Geissoschizine Methyl Ether in Rat and Human Liver Microsomes Using High-Performance Liquid Chromatography with Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hirotaka Kushida

    2015-01-01

    Full Text Available Geissoschizine methyl ether (GM is an indole alkaloid found in Uncaria hook, which is a galenical constituent of yokukansan, a traditional Japanese medicine. GM has been identified as the active component responsible for anti-aggressive effects. In this study, the metabolic profiling of GM in rat and human liver microsomes was investigated. Thirteen metabolites of GM were elucidated and identified using a high-performance liquid chromatography with tandem mass spectrometry method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, and chromatographic retention times. There were no differences in the metabolites between the rat and human liver microsomes. Among the 13 identified metabolites, there were two demethylation metabolites, one dehydrogenation metabolite, three methylation metabolites, three oxidation metabolites, two water-adduct metabolites, one di-demethylation metabolite, and one water-adduct metabolite followed by oxidation. The metabolic pathways of GM were proposed on the basis of this study. This study will be helpful in understanding the metabolic routes of GM and related Uncaria hook alkaloids, and provide useful information on the pharmacokinetics and pharmacodynamics. This is the first report that describes the separation and identification of GM metabolites in rat and human liver microsomes.

  15. Chloromethyl chlorosulfate: a new, catalytic method of preparation and reactions with some nucleophiles.

    Science.gov (United States)

    Power, Nicholas P; Bethell, Donald; Proctor, Lee; Latham, Elliot; Dawson, Paul

    2004-05-21

    The reaction of liquid (gamma-) SO3 with CH2Cl2 at room temperature leads to SO3 insertion into the C-Cl bonds, giving the useful chloromethylating agent chloromethyl chlorosulfate (CMCS). The process is very slow but becomes rapid on addition of catalytic quantities of trimethyl borate. The product mixture consists almost entirely of CMCS and the product of further sulfation, methylene bis(chlorosulfate)(MBCS), in a ratio of ca. 2 : 1, but typical yields of CMCS, isolated by distillation, are only 30-35%. The catalysed reaction in the homogeneous liquid phase at -45 degrees C has been followed as a function of time and of reactant concentration by 1H nmr spectroscopy. It is observed that, besides CMCS and MBCS, three additional, transient products (designated A, B and C) are formed. Products A, B and C decompose slowly at -45 degrees C but much more rapidly if the reaction mixture is raised to room temperature, giving additional CMCS and MBCS. From an analysis of the SO3 balance, it is inferred that products A, B and C arise from the reaction of one molecule of CH2Cl2 with respectively two, three and four molecules of SO3; they are suggested to be chloromethyl chloropolysulfates. By measuring initial rates of CMCS formation or total CH2Cl2 consumption, it is shown that the reaction is first order in the catalyst and roughly third order in SO3. A mechanistic scheme is proposed in which SO3 forms equilibrating zwitterionic molecular complexes with CH2Cl2. of 1 : 1, 2 : 1 and higher stoichiometries. The boron-containing catalyst can activate these complexes towards nucleophilic attack at carbon by the negatively charged oxygen of another zwitterion. An analogous mechanism can be written for the conversion of CMCS into MBCS by SO3 in the presence of trimethyl borate. CMCS reacts rapidly with anionic nucleophiles, such as halide or acetate ions (X-), in homogeneous solution of their tetrabutylammonium salts in CD3CN, or in a two-phase system (CDCl3/H2O) using alkali

  16. Reanalysis of the ground and three torsional excited states of trans-ethyl methyl ether by using an IAM-like tunneling matrix formalism

    Science.gov (United States)

    Kobayashi, Kaori; Sakai, Yusuke; Tsunekawa, Shozo; Miyamoto, Taihei; Fujitake, Masaharu; Ohashi, Nobukimi

    2016-03-01

    The trans-ethyl methyl ether has two inequivalent methyl internal rotors and shows tunneling splittings of maximum up to five components. However, the barrier of these two internal rotation potentials were relatively high and the five components were not resolved in the ground state microwave spectra. In this study, well-resolved Fourier transform microwave ground state spectrum was measured for the first time to resolve the five components. The ground state microwave spectra were reanalyzed based on these new measurements and the additional millimeter-wave spectra as well as those studied previously by Fuchs et al. Ninety Fourier transform microwave spectral lines were assigned to 107 transitions in the ground state and 3508 conventional microwave absorption lines were assigned up to Ka = 16 of the ground state, including all 707 lines reported by Fuchs et al. In addition, 10 transitions were observed by the double resonance experiment. They were least-squares-analyzed by the use of an internal axis method (IAM)-like tunneling matrix formalism based on an extended permutation-inversion group theoretical idea. Twenty-two molecular parameters composed of rotational constants, centrifugal distortion constants, internal rotation parameters and internal rotation tunneling parameters were determined for the ground state. The microwave spectra in the three torsionally excited states, that is, the ν28 = 1 C-CH3 torsional state, the ν29 = 1 O-CH3 torsional state and the ν30 = 1 skeletal torsional state, were also reanalyzed by using the IAM-like tunneling matrix formalism and somewhat extended line assignments.

  17. The silica-doped sulfonated poly(fluorenyl ether ketone)s membrane using hydroxypropyl methyl cellulose as dispersant for high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.F.; Wang, S.J.; Xiao, M.; Bian, S.G.; Meng, Y.Z. [State Key Laboratory of Optoelectronic Materials and Technologies, Institute of Optoelectronic and Functional Composite Materials, Sun Yat-sen University, Xingangxi Road, Guangzhou 510275 (China)

    2009-05-15

    The sulfonated poly(fluorenyl ether ketone)s (SPFEK) membranes doped with SiO{sub 2} and dispersed by hydroxypropyl methyl cellulose (HPMC) were prepared and investigated for polymer electrolyte membrane fuel cells (PEMFCs) used at high temperature and low relative humidity (RH). The above membrane was prepared by solution dispersion of SPFEK and SiO{sub 2} using HPMC as dispersant. The physio-chemical properties of the hybrid membrane were studied by means of scanning electron microscope (SEM), ion-exchange capacity (IEC), proton conductivity, and single cell performance tests. The hybrid membranes dispersed by HPMC were well dispersed when compared with common organic/inorganic hybrid membranes. The hybrid membranes showed superior characteristics as a proton exchange membrane (PEM) for PEMFC application, such as high ionic exchange content (IEC) of 1.51 equiv/g, high temperature operation properties, and the satisfactory ability of anti-H{sub 2} crossover. The single cell performances of the hybrid membranes were examined in a 5 cm{sup 2} commercial single cell at both 80 C and 120 C under different relative humidity (RH) conditions. The hybrid membrane dispersed by HPMC gave the best performance of 260 mW/cm{sup 2} under conditions of 0.4 V, 120 C, 50% RH and ambient pressure. The results demonstrated HPMC being an efficient dispersant for the organic/inorganic hybrid membrane used for PEM fuel cell. (author)

  18. Cytotoxic and DNA-damaging effects of methyl tert-butyl ether and its metabolites on HL-60 cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Tang, G.H. [Xian Medical Univ. (China); Shen, Y.; Shen, H.M. [National Univ. of Singapore (Singapore)] [and others

    1996-12-31

    Methyl tert-butyl ether (MTBE) is a widely used oxygenate in unleaded gasoline; however, few studies have been conducted on the toxicity of this compound. This study evaluates the cytotoxic and DNA-damaging effects of MTBE and its metabolites in a human haemopoietic cell line, HL-60. The metabolites of MTBE studied include tertiary butyl alcohol (TBA), {alpha}-hydroxyisobutyric acid (HIBA), and formaldehyde. Comet assay is used to assess DNA damage, and the cytotoxicity is investigated by lactate dehydrogenease (LDH) release. The results show no significant cytotoxic effects of MTBE, TBA, and HIBA over a concentration ranging from 1 to 30 mM. Formaldehyde, in contrast, causes a substantial LDH release at a concentration of 5 {mu}M. Hydrogen peroxide, a known oxidative agent, at concentrations ranging from 10 to 100 {mu}M, produces a significant dose-related increase in DNA damage, whereas a much higher concentration of MTBE (1 to 30 mM) is required to produce a similar observation. The genotoxic effects of TBA and HIBA appear to be identical to that of MTBE. Conversely, DNA damage is observed for formaldehyde at a relatively low concentration range (5 to 100 {mu}M). These findings suggest that MTBE and its metabolites, except formaldehyde, have relatively low cytotoxic and genotoxic effects. 16 refs., 4 figs.

  19. Poly(methyl vinyl ether-co-maleic acid)-polyethylene glycol nanocomposites cross-linked in situ with cellulose nanowhiskers.

    Science.gov (United States)

    Goetz, Lee; Foston, Marcus; Mathew, Aji P; Oksman, Kristiina; Ragauskas, Arthur J

    2010-10-11

    Nanocomposites were developed by cross-linking cellulose nanowhiskers with poly(methyl vinyl ether-co-maleic acid) and polyethylene glycol. Nuclear magnetic resonance (NMR) studies showed cross-linking occurs between the matrix and cellulose nanowhiskers via an esterification reaction. Proton NMR T(2) relaxation experiments provided information on the mobility of the polymer chains within the matrix, which can be related to the structure of the cross-linked nanocomposite. The nanocomposite was found to consist of mobile chain portions between cross-linked junction points and immobilized chain segments near or at those junction points, whose relative fraction increased upon further incorporation of cellulose nanowhiskers. Atomic force microscopy images showed a homogeneous dispersion of nanowhiskers in the matrix even at high nanowhisker content, which can be attributed to cross-linking of the nanowhiskers in the matrix. Relative humidity conditions were found to affect the mechanical properties of the composites negatively while the nanowhiskers content had a positive effect. It is expected that the cross-links between the matrix and the cellulose nanowhiskers trap the nanowhiskers in the cross-linked network, preventing nanowhisker aggregation subsequently producing cellulose nanocomposites with unique mechanical behaviors. The results show that in situ cross-linking of cellulose nanowhiskers with a matrix polymer is a promising route to obtain nanocomposites with well dispersed nanowhiskers, tailored nanostructure, and mechanical performance.

  20. Alternaria toxins: Altertoxin II is a much stronger mutagen and DNA strand breaking mycotoxin than alternariol and its methyl ether in cultured mammalian cells.

    Science.gov (United States)

    Fleck, Stefanie C; Burkhardt, Britta; Pfeiffer, Erika; Metzler, Manfred

    2012-10-02

    Altertoxin II (ATX II) is one of the several mycotoxins produced by Alternaria fungi. It has a perylene quinone structure and is highly mutagenic in Ames Salmonella typhimurium, but its mutagenicity in mammalian cells has not been studied before. Here we report that ATX II is a potent mutagen in cultured Chinese hamster V79 cells, inducing a concentration-dependent increase of mutations at the hypoxanthine guanine phosphoribosyltransferase gene locus at concentrations similar to that of the established mutagen 4-quinoline-N-oxide. Thus, ATX II is at least 50-times more potent as a mutagen than the common Alternaria toxins alternariol (AOH) and alternariol methyl ether (AME). In contrast to AOH and AME, ATX II does not affect the cell cycle of V79 cells. ATX II also causes DNA strand breaks in V79 cells, with a potency again exceeding that of AOH and AME. The high mutagenic and DNA strand breaking activity of ATX II raises the question of whether this Alternaria toxin poses a risk for public health, and warrants studies on the occurrence of ATX II and other perylene quinone-type mycotoxins in food and feed.

  1. Pulse radiolysis study of reactions of alkyl and alkylperoxy radicals originating from methyl tert-butyl ether in the gas phase

    DEFF Research Database (Denmark)

    Langer, S.; Ljungström, E.; Ellermann, T.;

    1995-01-01

    UV spectra and kinetics for the reactions of alkyl and alkylperoxy radicals from methyl tert-butyl ether (MTBE) were studied in 1 atm of SF6 by the pulse radiolysis-UV absorption technique. UV spectra for the radical mixtures were quantified from 215 to 340 nm. At 240 nm, sigma(R) = (2.6 +/- 0.4) X...... 10(-18) cm(2) molecule(-1) and sigma(RO2) = (4.1 +/- 0.6) X 10(-18) cm(2) molecule(-1) (base e). The rate constant for the self-reaction of the alkyl radicals is (2.5 +/- 1.1) X 10(-11) cm(3) molecule(-1) s(-1). The rate constants for reaction of the alkyl radicals with molecular oxygen...... and the alkylperoxy radicals with NO and NO2 are (9.1 +/- 1.5) X 10(-13), (4.3 +/- 1.6) X 10(-12) and (1.2 +/- 0.3) X 10(-11) cm(3) molecule(-1) s(-1), respectively. The rate constants given above refer to reaction at the tert-butyl side of the molecule....

  2. Cu(II), Zn(II) andMn(II) complexes of poly(methyl vinyl ether-alt-maleic anhydride). Synthesis, characterization and thermodynamic parameters

    Indian Academy of Sciences (India)

    Hidayet Mazi; Ali Gulpinar

    2014-01-01

    The complexes of poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) with Zn(II), Mn(II) and Cu(II) ions were synthesized from the reaction of the aqueous solution of copolymer and metal(II) chlorides at different temperatures ranging from 25° to 40°C. Elemental analysis of themetal-polymer complexes suggests that the metal to ligand ratio is 1:1. The formation constants of each complex were determined by the mol-ratio method. UV-Vis studies showed that the complex formation tendency increased in the following order: Zn(II) > Cu(II) > Mn(II). This order was confirmed by the Irving-William series and Pearson’s classification. The IR spectral data indicated the metal ions to be coordinated through the hydroxyl groups of the hydrolysed maleic anhydride. The intrinsic viscosity and thermal properties of the copolymer and metal-polymer complexes and their thermal stability are discussed.

  3. Preparation of Poly-(Methyl vinyl ether-co-maleic Anhydride Nanoparticles by Solution-Enhanced Dispersion by Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Kang

    2012-10-01

    Full Text Available The supercritical CO2-based technologies have been widely used in the formation of drug and/or polymer particles for biomedical applications. In this study, nanoparticles of poly-(methyl vinyl ether-co-maleic anhydride (PVM/MA were successfully fabricated by a process of solution-enhanced dispersion by supercritical CO2 (SEDS. A 23 factorial experiment was designed to investigate and identify the significance of the processing parameters (concentration, flow and solvent/nonsolvent for the surface morphology, particle size, and particle size distribution of the products. The effect of the concentration of PVM/MA was found to be dominant in the results regarding particle size. Decreasing the initial solution concentration of PVM/MA decreased the particle size significantly. After optimization, the resulting PVM/MA nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution. Fourier transform infrared spectroscopy (FTIR spectra demonstrated that the chemical composition of PVM/MA was not altered during the SEDS process and that the SEDS process was therefore a typical physical process. The absolute value of zeta potential of the obtained PVM/MA nanoparticles was larger than 40 mV, indicating the samples’ stability in aqueous suspension. Analysis of thermogravimetry-differential scanning calorimetry (TG-DSC revealed that the effect of the SEDS process on the thermostability of PVM/MA was negligible. The results of gas chromatography (GC analysis confirmed that the SEDS process could efficiently remove the organic residue.

  4. Short-term fish reproduction assays with methyl tertiary butyl ether with zebrafish and fathead minnow: Implications for evaluation of potential for endocrine activity.

    Science.gov (United States)

    Mihaich, Ellen; Erler, Steffen; Le Blanc, Gerald; Gallagher, Sean

    2015-09-01

    The authors report on short-term fish reproduction assays in zebrafish and fathead minnow conducted to examine the potential for methyl tertiary butyl ether (MTBE) to cause effects on the endocrine system. Both studies were performed under good laboratory practice and in accordance with Organisation for Economic Co-operation and Development and US Environmental Protection Agency test guidelines. The results of the first study demonstrated that exposure to a high test concentration (147 mg/L) of MTBE impaired reproductive output of female zebrafish, evident by a reduction in fecundity. Based on the endpoints evaluated in the present study however, there was no supporting evidence to indicate that this effect was caused by disruption of or interaction with the endocrine system. In the second study, fathead minnows exposed to a wider but lower range of test concentrations showed no effects on any reproductive parameter of male or female fish, at the maximum recommended testing concentration of 100 mg/L (62 mg/L measured). The results of these 2 guideline studies indicate that MTBE does not interact with the hypothalamic-pituitary-gonadal axis of zebrafish or fathead minnow.

  5. Reutilization of waste scrap tyre as the immobilization matrix for the enhanced bioremoval of a monoaromatic hydrocarbons, methyl tert-butyl ether, and chlorinated ethenes mixture from water.

    Science.gov (United States)

    Lu, Qihong; de Toledo, Renata Alves; Xie, Fei; Li, Junhui; Shim, Hojae

    2017-04-01

    BTEX (benzene, toluene, ethylbenzene, ortho-, meta-, and para-xylenes), methyl tert-butyl ether (MTBE), cis-1,2-dichloroethylene (cis-DCE), and trichloroethylene (TCE) are among the major soil and groundwater contaminants frequently co-existing, as a result of their widespread uses. Pseudomonas plecoglossicida was immobilized on waste scrap tyre to remove these contaminants mixture from synthetic contaminated water. The microbial activity was enhanced in the immobilized system, shown by the higher colony forming units (CFUs) (40%), while BTEX were used as growth substrates. The adsorption capacity of tyres toward contaminants reached a maximum within one day, with BTEX (76.3%) and TCE (64.3%) showing the highest sorption removal capacities, followed by cis-DCE (30.0%) and MTBE (11.0%). The adsorption data fitted the Freundlich isotherm with a good linear correlation (0.989-0.999) for the initial contaminants concentration range applied (25-125mg/L). The monoaromatic hydrocarbons were almost completely removed in the immobilized system and the favourable removal efficiencies of 78% and 90% were obtained for cis-DCE and TCE, respectively. The hybrid (biological, immobilization/physical, sorption) system was further evaluated with the contaminants spiked intermittently for the stable performance. The addition of mineral salt medium further enhanced the bioremoval of contaminants by stimulating the microbial growth to some extent.

  6. Substantial production of drosophilin A methyl ether (tetrachloro-1,4-dimethoxybenzene) by the lignicolous basidiomycete Phellinus badius in the heartwood of mesquite ( Prosopis juliflora) trees

    Science.gov (United States)

    Garvie, Laurence A. J.; Wilkens, Barry; Groy, Thomas L.; Glaeser, Jessie A.

    2015-04-01

    Toxic organohalogen pollutants produced as by-products of industrial processes, such as chloroform and polychlorinated dibenzo- p-dioxins, also have significant natural sources. A substantial terrestrial source of halogenated organics originates from fungal decay of wood and leaf litter. Here we show that the lignicolous basidiomycete Phellinus badius deposits up to 30,000 mg of the halogenated metabolite drosophilin A methyl ether (DAME, tetrachloro-1,4-dimethoxybenzene) per kilogram of decayed heartwood in the mesquite Prosopis juliflora. DAME occurs as clusters of glassy crystals up to 1 mm long within the decayed heartwood. In addition, the Phellinus badius basidiocarps contain an average of 24,000 mg DAME/kg dried fruiting body, testifying to the significant translocation and accumulation of Cl accompanied by DAME biosynthesis. The high DAME concentrations attest to the substantial Cl content of the heartwood, which averages near 5,000 ppm, with Cl/K near 1:1, consistent with an inorganic chloride precursor. Phellinus badius has a circumglobal distribution in the tropics and subtropics, where it is widely distributed on hardwoods and commonly associated with decay of mesquite. There is the potential for extensive DAME formation within decayed heartwood worldwide given the extensive range of Phellinus badius and its propensity to form DAME within mesquites. Further, DAME production is not limited to Phellinus badius but occurs in a range of lignicolous basidiomycetes, suggesting a significant natural reservoir for this chloroaromatic with potential environmental implications.

  7. Concentrations and potential health risks of methyl tertiary-butyl ether (MTBE) in air and drinking water from Nanning, South China.

    Science.gov (United States)

    Zhang, Li'e; Qin, Jian; Zhang, Zhiyong; Li, Qin; Huang, Jiongli; Peng, Xiaowu; Qing, Li; Liang, Guiqiang; Liang, Linhan; Huang, Yuman; Yang, Xiaobo; Zou, Yunfeng

    2016-01-15

    Levels of methyl tertiary-butyl ether (MTBE) in occupational air, ambient air, and drinking water in Nanning, South China, were investigated, and then their potential health risks to occupational workers and the general public were evaluated. Results show that the MTBE concentration in occupational air from 13 service stations was significantly higher than that in ambient air from residential areas (pwater samples from household taps yielded detectable MTBE in the range of 0.04-0.33 μg/L, which is below the US drinking water standard of 20-40 μg/L. The non-carcinogenic risk of MTBE from air inhalation may be negligible because the calculated hazard quotient was less than 1. The mean MTBE lifetime cancer risk was within the acceptable limit of 1 × 10(-6) to 1 × 10(-4), but the lifetime cancer risk of refueling workers in the urban service station at the 95th percentile slightly exceeded the maximum acceptable carcinogen risk (1 × 10(-4)), indicating the potential carcinogenic health effects on the population highly exposed to MTBE in this region. The hazard index and carcinogenic risk of MTBE in drinking water were significantly lower than the safe limit of US Environmental Protection Agency, suggesting that drinking water unlikely poses significant health risks to the residents in Nanning.

  8. Polyphenol-Rich Fraction from Larrea divaricata and its Main Flavonoid Quercetin-3-Methyl Ether Induce Apoptosis in Lymphoma Cells Through Nitrosative Stress.

    Science.gov (United States)

    Martino, Renzo; Arcos, María Laura Barreiro; Alonso, Rosario; Sülsen, Valeria; Cremaschi, Graciela; Anesini, Claudia

    2016-07-01

    Larrea divaricata is a plant with antiproliferative principles. We have previously identified the flavonoid quercetin-3-methyl ether (Q-3-ME) in an ethyl acetate fraction (EA). Both the extract and Q-3-ME were found to be effective against the EL-4 T lymphoma cell line. However, the mechanism underlying the inhibition of tumor cell proliferation remains to be elucidated. In this work, we analyzed the role of nitric oxide (NO) in the induction of apoptosis mediated by Q-3-ME and EA. Both treatments were able to induce apoptosis in a concentration-dependent and time-dependent manner. The western blot analysis revealed a sequential activation of caspases-9 and 3, followed by poly-(ADP-ribose)-polymerase cleavage. EA and Q-3-ME lowered the mitochondrial membrane potential, showing the activation of the intrinsic pathway of apoptosis. Q-3-ME and EA increased NO production and inducible NO synthase expression in tumor cells. The involvement of NO in cell death was confirmed by the nitric oxide synthases inhibitor L-NAME. In addition, EA and Q-3-ME induced a cell cycle arrest in G0/G1 phase. These drugs did not affect normal cell viability. This data suggested that EA and Q-3-ME induce an increase in NO production that would lead to the cell cycle arrest and the activation of the intrinsic pathway of apoptosis. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Effects of the ether phospholipid AMG-PC on mast cells are similar to that of the ether lipid AMG but different from that of the analogue hexadecylphosphocholine

    DEFF Research Database (Denmark)

    Grosman, Nina

    1991-01-01

    Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell......Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell...

  10. Simultaneous determination of methyl tert.-butyl ether and its degradation products, other gasoline oxygenates and benzene, toluene, ethylbenzene and xylenes in Catalonian groundwater by purge-and-trap-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Rosell, Mònica; Lacorte, Sílvia; Ginebreda, Antoni; Barceló, Damià

    2003-05-02

    In Catalonia (northeast Spain), a monitoring program was carried out to determine methyl tert.-butyl ether (MTBE), its main degradation products, tert.-butyl alcohol (TBA), tert.-butyl formate (TBF), and other gasoline additives, the oxygenate dialkyl ethers ethyl tert.-butyl ether, tert.-amyl methyl ether and diisopropyl ether and the aromatic compounds benzene, toluene, ethylbenzene and xylene (BTEX) in 21 groundwater wells that were located near different gasoline point sources (a gasoline spill and underground storage tank leakage). Purge-and-trap coupled to gas chromatography-mass spectrometry was optimised for the simultaneous determination of the above mentioned compounds and enabled to detect concentrations at ng/l or sub-microg/l concentrations. Special attention was given to the determination of polar MTBE degradation products, TBA and TBF, since not much data on method performance and environmental levels are given on these compounds in groundwater. All samples analysed contained MTBE at levels between 0.3 and 70 microg/l. Seven contaminated hot spots were identified with levels up to US Environmental Protection Agency drinking water advisory (20-40 microg/l) and a maximum concentration of 670 microg/l (doubling the Danish suggested toxicity level of 350 microg/l). Samples with high levels of MTBE contained 0.1-60 microg/l of TBA, indicating (but not proving) in situ degradation of parent compound. In all cases, BTEX was at low concentrations or not detected showing less solubility and persistence than MTBE. This fact confirms the suitability of MTBE as a tracer or indicator of long-term gasoline contamination than the historically used BTEX.

  11. Detection of active matriptase using a biotinylated chloromethyl ketone peptide.

    Directory of Open Access Journals (Sweden)

    Sine Godiksen

    Full Text Available Matriptase is a member of the family of type II transmembrane serine proteases that is essential for development and maintenance of several epithelial tissues. Matriptase is synthesized as a single-chain zymogen precursor that is processed into a two-chain disulfide-linked form dependent on its own catalytic activity leading to the hypothesis that matriptase functions at the pinnacle of several protease induced signal cascades. Matriptase is usually found in either its zymogen form or in a complex with its cognate inhibitor hepatocyte growth factor activator inhibitor 1 (HAI-1, whereas the active non-inhibited form has been difficult to detect. In this study, we have developed an assay to detect enzymatically active non-inhibitor-complexed matriptase by using a biotinylated peptide substrate-based chloromethyl ketone (CMK inhibitor. Covalently CMK peptide-bound matriptase is detected by streptavidin pull-down and subsequent analysis by Western blotting. This study presents a novel assay for detection of enzymatically active matriptase in living human and murine cells. The assay can be applied to a variety of cell systems and species.

  12. In vitro evaluation of poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Rusen, Laurentiu [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Neacsu, Patricia; Cimpean, Anisoara [University of Bucharest, Department of Biochemistry and Molecular Biology, Bucharest (Romania); Valentin, Ion; Brajnicov, Simona; Dumitrescu, L.N. [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Banita, Janina [University of Bucharest, Faculty of Chemistry, Bucharest (Romania); IBAR, Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, RO-060031 Bucharest (Romania); Dinca, Valentina, E-mail: valentina.dinca@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania); Dinescu, Maria [National Institute for Lasers, Plasma and Radiation Physics, Bucharest (Romania)

    2016-06-30

    Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

  13. Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

    Science.gov (United States)

    Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V.; Noll, Thomas; Funk, Richard H. W.; Engelmann, Katrin; Werner, Carsten

    2015-08-01

    Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

  14. Conjugation of salmon calcitonin to a combed-shaped end functionalized poly(poly(ethylene glycol) methyl ether methacrylate) yields a bioactive stable conjugate.

    Science.gov (United States)

    Ryan, Sinéad M; Wang, Xuexuan; Mantovani, Guiseppe; Sayers, Claire T; Haddleton, David M; Brayden, David J

    2009-04-02

    Salmon calcitonin (sCT) was conjugated via its N-terminal cysteine to a comb-shaped end-functionalized poly(poly(ethylene glycol) methyl ether methacrylate) (PolyPEG, 6.5 kDa), and to linear PEG (5 kDa). Conjugate molecular weight and purity was assessed by SEC-HPLC and MALDI-TOF MS. Bioactivity of conjugates was measured by cyclic AMP assay in T47D cells. Calcium and calcitonin levels were measured in rats following intravenous injections. Stability of conjugates was tested against serine proteases, intestinal and liver homogenates and serum. Cytotoxicity of conjugates was assessed by lactate dehydrogenase (LDH) assay and by haemolytic assay of rat red blood cells. Results showed that the two conjugates were of high purity with molecular weights similar to predictions. Both conjugates retained more than 85% bioactivity in vitro and had nanomolar EC(50) values similar to sCT. While both sCT-PolyPEG(6.5 K) and sCT-PEG(5 K) were resistant to metabolism by serine proteases, homogenates and serum, PolyPEG (6.5 K) was more so. Although both conjugates reduced serum calcium to levels similar to those achieved with sCT, PolyPEG(6.5 K) extended the T(1/2) and AUC of serum sCT over values achieved with sCT-PEG and sCT itself. None of PolyPEG, PEG or methacrylic acid displayed significant cytotoxicity. PolyPEG may therefore have potential to improve pharmacokinetic profiles of injected peptides.

  15. In vitro evaluation of poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether copolymer coating effects on cells adhesion and proliferation

    Science.gov (United States)

    Rusen, Laurentiu; Neacsu, Patricia; Cimpean, Anisoara; Valentin, Ion; Brajnicov, Simona; Dumitrescu, L. N.; Banita, Janina; Dinca, Valentina; Dinescu, Maria

    2016-06-01

    Understanding and controlling natural and synthetic biointerfaces is known to be the key to a wide variety of application within cell culture and tissue engineering field. As both material characteristics and methods are important in tailoring biointerfaces characteristics, in this work we explore the feasibility of using Matrix Assisted Pulsed Laser Evaporation technique for obtaining synthetic copolymeric biocoatings (i.e. poly(ethylene glycol)-block-poly(ɛ-caprolactone) methyl ether) for evaluating in vitro Vero and MC3T3-E1 pre-osteoblasts cell response. Characterization and evaluation of the coated substrates were carried out using different techniques. The Fourier transform infrared spectroscopy data demonstrated that the main functional groups in the MAPLE-deposited films remained intact. Atomic Force Microscopy images showed the coatings to be continuous, with the surface roughness depending on the deposition parameters. Moreover, the behaviour of the coatings in medium mimicking the pH and temperature of the human body was studied and corelated to degradation. Spectro-ellipsometry (SE) and AFM measurements revealed the degradation trend during immersion time by the changes in coating thickness and roughness. In vitro biocompatibility was studied by indirect contact tests on Vero cells in accordance with ISO 10993-5/2009. The results obtained in terms of cell morphology (phase contrast microscopy) and cytotoxicity (LDH and MTT assays) proved biocompatibility. Furthermore, direct contact assays on MC3T3-E1 pre-osteoblasts demonstrated the capacity of all analyzed specimens to support cell adhesion, normal cellular morphology and growth.

  16. Unveiling the Dynamics of Self-Assembled Layers of Thin Films of Poly(vinyl methyl ether) (PVME) by Nanosized Relaxation Spectroscopy.

    Science.gov (United States)

    Madkour, Sherif; Szymoniak, Paulina; Heidari, Mojdeh; von Klitzing, Regine; Schönhals, Andreas

    2017-03-01

    A combination of nanosized dielectric relaxation (BDS) and thermal spectroscopy (SHS) was utilized to characterize the dynamics of thin films of poly(vinyl methyl ether) (PVME) (thicknesses: 7-160 nm). For the BDS measurements, a recently designed nanostructured electrode system is employed. A thin film is spin-coated on an ultraflat highly conductive silicon wafer serving as the bottom electrode. As top electrode, a highly conductive wafer with nonconducting nanostructured SiO2 nanospacers with heights of 35 or 70 nm is assembled on the bottom electrode. This procedure results in thin supported films with a free polymer/air interface. The BDS measurements show two relaxation processes, which are analyzed unambiguously for thicknesses smaller than 50 nm. The relaxation rates of both processes have different temperature dependencies. One process coincides in its position and temperature dependence with the glassy dynamics of bulk PVME and is ascribed to the dynamic glass transition of a bulk-like layer in the middle of the film. The relaxation rates were found to be thickness independent as confirmed by SHS. Unexpectedly, the relaxation rates of the second process obey an Arrhenius-like temperature dependence. This process was not observed by SHS and was related to the constrained fluctuations in a layer, which is irreversibly adsorbed at the substrate with a heterogeneous structure. Its molecular fluctuations undergo a confinement effect resulting in the localization of the segmental dynamics. To our knowledge, this is the first report on the molecular dynamics of an adsorbed layer in thin films.

  17. Sensitivity of green and blue-green algae to methyl tert-butyl ether (MTBE) during a fifteen-day test

    Institute of Scientific and Technical Information of China (English)

    CHEN Jianmeng; MA Jianyi; CAO Wei; WANG Pinwei; TONG Senmiao; SUN Yizhao

    2009-01-01

    The test was designed to assess the toxicity of methyl tert-butyl ether (MTBE) to Chlorella ellipsoidea and Aphanizomenon flos-aquae during 15 d with concentrations of MTBE from high (2.00×104 mg/L) to low (2 mg/L). The results showed that the toxicity was low when the concentration of MTBE was 1.00×104-2.00×104 mg/L (the greatest inhibition of growth-rate was 70%-71%, occurring on day 1-5). Low concentrations (2-500 mg/L) stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L on day 3-5. The low concentrations may lead to an algal bloom owing to overabundance, which represents an aquatic ecological risk. However, the stimulatory effect occurred only during the day 1-5 and disappeared gradually during the day 13-15. The toxicity of MTBE (72-120 h EC50) is 6.65×103-9.58×103 mg/L for C. ellipsoidea and that is 1.14×104-2.00×104 mg/L for A. spiroides. We found that the toxicity and ecological risk of MTBE for the algal community structure were low. The toxicity was influenced by the duration of the test. We suggest that the duration of the test should not be shorter than half a life-cycle.

  18. High strength of physical hydrogels based on poly(acrylic acid)-g-poly(ethylene glycol) methyl ether: role of chain architecture on hydrogel properties.

    Science.gov (United States)

    Yang, Jun; Gong, Cheng; Shi, Fu-Kuan; Xie, Xu-Ming

    2012-10-04

    This investigation was to study the connections between polymer branch architecture of physical hydrogels and their properties. The bottle-brush-like polymer chains of poly(acrylic acid)-g-poly(ethylene glycol) methyl ether (PAA-g-mPEG) with PAA as backbones and mPEG as branch architecture were synthesized and in situ grafted from silica nanoparticles (SNs) to construct hydrogels cross-linked networks in aqueous solutions. The structural variables to be discussed included molecular weight and molar ratio of branch chains, and new aspects of the formation mechanism of physical hydrogels with branch structure in the absence of organic cross-links were present. The results indicated that the differences of polymer chain architecture could be distinguished via their different interactions that are present by gelation process and mature gel properties, such as gel strength and swelling ratio. The gelation occurred at the critical polymer concentration and molecular weight, respectively, and the inorganic/organic (SNs/PAA-g-mPEG) nanoparticles began to entangle and construct the cross-linking networks afterward. The gel-to-sol transition temperature (T(g-s)) and radii of SNs that were encapsulated by polymer chains as a function of time for chains' disentanglement were monitored according to the observation of the dissolution process, and the molecular weight between two consecutive entanglements (M(e)) was calculated thereafter. This study showed that the introduction of branch chain onto the linear backbone significantly promoted the chain interactions and increased entanglement density, which contributed to the hydrogels' network integrity and rigidity, thus illustrating greater elongation at break and tensile strength than the hydrogels formulated with linear polymer chains.

  19. Using groundwater age distributions to understand changes in methyl tert-butyl ether (MtBE) concentrations in ambient groundwater, northeastern United States

    Science.gov (United States)

    Lindsey, Bruce; Ayotte, Joseph; Jurgens, Bryant; DeSimone, Leslie

    2017-01-01

    Temporal changes in methyl tert-butyl ether (MtBE) concentrations in groundwater were evaluated in the northeastern United States, an area of the nation with widespread low-level detections of MtBE based on a national survey of wells selected to represent ambient conditions. MtBE use in the U.S. peaked in 1999 and was largely discontinued by 2007. Six well networks, each representing specific areas and well types (monitoring or supply wells), were each sampled at 10 year intervals between 1996 and 2012. Concentrations were decreasing or unchanged in most wells as of 2012, with the exception of a small number of wells where concentrations continue to increase. Statistically significant increasing concentrations were found in one network sampled for the second time shortly after the peak of MtBE use, and decreasing concentrations were found in two networks sampled for the second time about 10 years after the peak of MtBE use. Simulated concentrations from convolutions of estimates for concentrations of MtBE in recharge water with age distributions from environmental tracer data correctly predicted the direction of MtBE concentration changes in about 65 percent of individual wells. The best matches between simulated and observed concentrations were found when simulating recharge concentrations that followed the pattern of national MtBE use. Some observations were matched better when recharge was modeled as a plume moving past the well from a spill at one point in time. Modeling and sample results showed that wells with young median ages and narrow age distributions responded more quickly to changes in the contaminant source than wells with older median ages and broad age distributions. Well depth and aquifer type affect these responses. Regardless of the timing of decontamination, all of these aquifers show high susceptibility for contamination by a highly soluble, persistent constituent.

  20. A Convenient and Efficient Procedure for Oxime Ethers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70 - 96%.

  1. A Convenient and Efficient Procedure fox Oxime Ethers

    Institute of Scientific and Technical Information of China (English)

    ChunBaoLI; MichaelC.K.CHOI; 等

    2002-01-01

    Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70-96%.

  2. FLUORESCENCE STUDIES ON MORPHOLOGICAL CHANGE OF ST/DVB CROSSLINKED GELS DURING CHLOROMETHYLATION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with increase of chlorine content, the excimer emission band (~325nm)approaches to vanish, while the intensity of multi-ring aggregate emission band (~420nm) quicklyreaches a maximum, and then decreases sharply accompanied by appearance ofa new broad bandcentred at ca 488nm which roughly coincides with the typical emission band of hypercrossllinkedSt/DVB gels. Mearwhile, the result of IR measurement suggests that methylene bridge between phenylrings forms and increases with chloromethylation process. These results are explained in terms ofaside reaction of post-crosslinking, which densifies the loosely crosslinked networks and undoes thedensely entangled microgel nuclei. As a result, the morphology of the crosslinked gels becom es morehomogeneous with chloromethylation.

  3. Volumetric behaviour of the ternary liquid system composed of methyl tert-butyl ether, toluene, and isooctane at temperatures from (298.15 to 328.15) K: Experimental data and correlation

    Energy Technology Data Exchange (ETDEWEB)

    Moravkova, L.; Wagner, Z.; Sedlakova, Z. [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic); Linek, J., E-mail: linek@icpf.cas.c [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic)

    2010-07-15

    The densities and speeds of sound of (methyl tert-butyl ether left braceMTBEright brace + toluene + isooctane) were measured at four temperatures over the range (298.15 to 328.15) K and the respective values of excess volumes V{sub m}{sup E} and adiabatic compressibility kappa{sub S} were calculated. The V{sub m}{sup E} and kappa{sub S} values for the ternary and corresponding binaries were fitted to the Redlich-Kister equation considering various numbers of ternary constants. The necessary number of ternary constants needed to describe the system is discussed.

  4. Phase Behavior of Poly(vinylidene fluoride)-graft-poly(diethylene glycol methyl ether methacrylate) in Alcohol-Water System: Coexistence of LCST and UCST.

    Science.gov (United States)

    Kuila, Atanu; Maity, Nabasmita; Chatterjee, Dhruba P; Nandi, Arun K

    2016-03-10

    A thermoresponsive polymer poly(diethylene glycol methyl ether methacrylate) (PMeO2MA) is grafted from poly(vinylidene fluoride) (PVDF) backbone by using a combined ATRC and ATRP technique with a high conversion (69%) of the monomer to produce the graft copolymer (PD). It is highly soluble polymer and its solution property is studied by varying polarity in pure solvents (water, methanol, isopropanol) and also in mixed solvents (water-methanol and water-isopropanol) by measuring the hydrodynamic size (Z-average) of the particles by dynamic light scattering (DLS). The variation of Z-average size with temperature of the PD solution (0.2%, w/v) indicates a lower critical solution temperature (LCST)-type phase transition (T(PL)) in aqueous medium, an upper critical solution temperature (UCST)-type phase transition (T(PU)) in isopropanol medium, and no such phase transition for methanol solution. In the mixed solvent (water + isopropanol) at 0-20% (v/v) isopropanol the TPL increases, whereas the T(PU) decreases at 92-100% with isopropanol content. For the mixture 20-90% isopropanol, PD particles having larger sizes (400-750 nm) exhibit neither any break in Z-average size-temperature plot nor any cloudiness, indicating their dispersed swelled state in the medium. In the methanol + water mixture with methanol content of 0-30%, T(PL) increases, and at 40-60% both UCST- and LCST-type phase separations occur simultaneously, but at 70-90% methanol the swelled state of the particles (size 250-375 nm) is noticed. For 50 vol % methanol by varying polymer concentration (0.07-0.2% w/v) we have drawn a quasibinary phase diagram that indicates an approximate inverted hourglass phase diagram where a swelled state exists between two single phase boundary produced from LCST- and UCST-type phase transitions. An attempt is made to understand the phase separation process by temperature-dependent (1)H NMR spectroscopy along with transmission electron microscopy.

  5. Quercetin 3-O-methyl ether protects FL83B cells from copper induced oxidative stress through the PI3K/Akt and MAPK/Erk pathway

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Hsiao-Ling, E-mail: lily1001224@gmail.com [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Li, Chia-Jung, E-mail: 97751101@stmail.tcu.edu.tw [Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan (China); Huang, Lin-Huang, E-mail: yg1236@yahoo.com.tw [School of Medicine, Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan (China); Chen, Chun-Yao, E-mail: cychen@mail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Tsai, Chun-Hao, E-mail: 100726105@stmail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China); Lin, Chun-Nan, E-mail: lincna@cc.kmu.edu.tw [Faculty of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Biological Science and Technology, School of Medicine, China Medical University, Taichung, Taiwan (China); Hsu, Hsue-Yin, E-mail: hsueyin@mail.tcu.edu.tw [Department of Life Sciences, Tzu Chi University, Hualien, Taiwan (China)

    2012-10-01

    Quercetin is a bioflavonoid that exhibits several biological functions in vitro and in vivo. Quercetin 3-O-methyl ether (Q3) is a natural product reported to have pharmaceutical activities, including antioxidative and anticancer activities. However, little is known about the mechanism by which it protects cells from oxidative stress. This study was designed to investigate the mechanisms by which Q3 protects against Cu{sup 2+}-induced cytotoxicity. Exposure to Cu{sup 2+} resulted in the death of mouse liver FL83B cells, characterized by apparent apoptotic features, including DNA fragmentation and increased nuclear condensation. Q3 markedly suppressed Cu{sup 2+}-induced apoptosis and mitochondrial dysfunction, characterized by reduced mitochondrial membrane potential, caspase-3 activation, and PARP cleavage, in Cu{sup 2+}-exposed cells. The involvement of PI3K, Akt, Erk, FOXO3A, and Mn-superoxide dismutase (MnSOD) was shown to be critical to the survival of Q3-treated FL83B cells. The liver of both larval and adult zebrafish showed severe damage after exposure to Cu{sup 2+} at a concentration of 5 μM. Hepatic damage induced by Cu{sup 2+} was reduced by cotreatment with Q3. Survival of Cu{sup 2+}-exposed larval zebrafish was significantly increased by cotreatment with 15 μM Q3. Our results indicated that Cu{sup 2+}-induced apoptosis in FL83B cells occurred via the generation of ROS, upregulation and phosphorylation of Erk, overexpression of 14-3-3, inactivation of Akt, and the downregulation of FOXO3A and MnSOD. Hence, these results also demonstrated that Q3 plays a protective role against oxidative damage in zebrafish liver and remarked the potential of Q3 to be used as an antioxidant for hepatocytes. Highlights: ► Protective effects of Q3 on Cu{sup 2+}-induced oxidative stress in vitro and in vivo. ► Cu{sup 2+} induced apoptosis in FL83B cells via ROS and the activation of Erk. ► Q3 abolishes Cu{sup 2+}-induced apoptosis through the PI3K/Akt and MAPK

  6. Relationship between Methyl Tertiary Butyl Ether Exposure and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study among Petrol Station Attendants in Southern China

    Directory of Open Access Journals (Sweden)

    Jianping Yang

    2016-09-01

    Full Text Available Methyl tertiary butyl ether (MTBE—A well known gasoline additive substituting for lead alkyls—causes lipid disorders and liver dysfunctions in animal models. However, whether MTBE exposure is a risk factor for non-alcoholic fatty liver disease (NAFLD remains uncertain. We evaluate the possible relationship between MTBE exposure and the prevalence of NAFLD among 71 petrol station attendants in southern China. The personal exposure concentrations of MTBE were analyzed by Head Space Solid Phase Microextraction GC/MS. NAFLD was diagnosed by using abdominal ultrasonography according to the guidelines for the diagnosis and treatment of NAFLD suggested by the Chinese Hepatology Association. Demographic and clinical characteristics potentially associated with NAFLD were investigated. Mutivariate logistic regression analysis was applied to measure odds ratios and 95% confidence intervals (CI. The result showed that the total prevalence of NAFLD was 15.49% (11/71 among the study subjects. The average exposure concentrations of MTBE were 292.98 ± 154.90 μg/m3 and 286.64 ± 122.28 μg/m3 in NAFLD and non-NAFLD groups, respectively, and there was no statistically significant difference between them (p > 0.05. After adjusting for age, gender, physical exercise, body mass index (BMI, systolic blood pressure (SBP, diastolic blood pressure (DBP, alanine aminotransferase (ALT, white blood cell (WBC, total cholesterol (TC, triglycerides (TG, low-density lipoprotein (LDL, and high-density lipoprotein (HDL, the odds ratios were 1.31 (95% CI: 0.85–1.54; p > 0.05, 1.14 (95% CI: 0.81–1.32; p > 0.05, 1.52 (95% CI: 0.93–1.61; p > 0.05 in the groups (including men and women with exposure concentrations of MTBE of 100–200 μg/m3, 200–300 μg/m3, and ≥300 μg/m3, respectively, as compared to the group (including men and women ≤100 μg/m3. Our investigation indicates that exposure to MTBE does not seem to be a significant risk factor for the prevalence of

  7. Crosslinked Hexafluoropropylidene Polybenzimidazole Membranes with Chloromethyl Polysulfone for Fuel Cell Applications

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Qingfeng; Cleemann, Lars Nilausen;

    2013-01-01

    membranes with chloromethyl polysulfone as a polymeric crosslinker. Comparing with linear F6PBI and mPBI membranes, the polymer crosslinked F6PBI membranes exhibited little organo solubility, excellent stability towards the radical oxidation, high resistance to swelling in concentrated phosphoric acid...

  8. Molecularly Imprinted Polymers on Chloromethyl Polystyrene Resin Prepared via RAFT Polymerization

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.

  9. Synthesis of the insecticide prothrin and its analogues from biomass-derived 5-(chloromethyl)furfural.

    Science.gov (United States)

    Chang, Fei; Dutta, Saikat; Becnel, James J; Estep, Alden S; Mascal, Mark

    2014-01-15

    Prothrin, a synthetic pyrethroid insecticide, was synthesized from the biomass-derived platform chemical 5-(chloromethyl)furfural in six steps and overall 65% yield. Two structural analogues of prothrin were also prepared following the same synthetic approach. Preliminary testing of these furan-based pyrethroids against the yellow fever mosquito Aedes aegypti indicates promising insecticidal activities.

  10. Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Ferreira, N.

    2005-11-15

    Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

  11. Synthesis and physicochemical properties of propylene glycol methyl ether palm oil monoester%棕榈油丙二醇甲醚酯生物柴油合成及理化性能试验研究

    Institute of Scientific and Technical Information of China (English)

    王文国; 王煊军; 郭和军; 张剑

    2011-01-01

    以丙二醇甲醚和精制棕榈油为原料,以金属钠为催化剂合成了一种新型生物柴油.即棕榈油丙二醇甲醚酯.通过正交试验设计获得了目标产物的最佳合成条件:醇(丙二醇甲醚)油摩尔比10:1,催化剂用量(占棕榈油质量)1.2%,反应温度90℃,反应时间2 h.在最佳合成条件下所得目标产物产率高达91.3%.利用红外光谱及氢核磁共振分析仪对产物进行了结构表征与化学结构分析,表明目标产物的化学结构与预测结果一致.理化性能试验表明,生物柴油的主要性能指标和我国0柴油较为接近,完全可以满足柴油发动机的使用要求.%A new biodiesel of propylene glycol methyl ether palm oil monoester(PGMEPOM) was synthesized with propylene glycol methyl ether and palm oil as reagents and sodium as a catalyst. The optimum conditions were determined by orthogonal as follows: molar ratio of propylene glycol methyl ether to palm oil 10:1, sodium dose 1.2%, reaction temperature 90℃ and reaction time 2 h. The productive rate of ester reached 91.3% under these conditions. In addition,the FT- IR and 1H NMR analysis showed that the chemical structure of PGMEPOM was consistent with the forecasting result. The main properties of PGMEPOM closed to that of 0# diesel, which proved that the PGMEPOM could meet the demands of diesel engine.

  12. On the predictive capabilities of CPA for applications in the chemical industry: Mulficomponent mixtures containing methyl-methacrylate, dimethyl-ether or acetic acid

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Kontogeorgis, Georgios

    2014-01-01

    with acetic acid, esters, ethers and alcohols, and in this case for water-acetic acid the CPA-Huron Vidal (CPA-HV) version of the model is used. For the latter binary mixture, new CPA-HV binary parameter sets are estimated using, among others, data for activity coefficients at infinite dilutions. The modeling...... for the acetic acid-water system for which different parameter sets at different temperatures can be recommended. Even with the use of CPA-HV mixing rules, modeling of the acetic acid-water system with few interaction parameters remains a challenging task. Excellent simultaneous VLE and LLE correlation...... is obtained for complex systems such as aqueous mixtures with ethers and esters. The multicomponent results are, with a few exceptions, very satisfactory, especially for the vapor-liquid equilibrium cases. For the demanding aqueous acetic acid-water containing systems, one parameter set is recommended...

  13. Methyl-perfluoroheptene-ethers (CH3OC7F13): measured OH radical reaction rate coefficients for several isomers and enantiomers and their atmospheric lifetimes and global warming potentials.

    Science.gov (United States)

    Jubb, Aaron M; Gierczak, Tomasz; Baasandorj, Munkhbayar; Waterland, Robert L; Burkholder, James B

    2014-05-06

    Mixtures of methyl-perfluoroheptene-ethers (CH3OC7F13, MPHEs) are currently in use as replacements for perfluorinated alkanes (PFCs) and poly-ether heat transfer fluids, which are persistent greenhouse gases with lifetimes >1000 years. At present, the atmospheric processing and environmental impact from the use of MPHEs is unknown. In this work, rate coefficients at 296 K for the gas-phase reaction of the OH radical with six key isomers (including stereoisomers and enantiomers) of MPHEs used commercially were measured using a relative rate method. Rate coefficients for the six MPHE isomers ranged from ∼ 0.1 to 2.9 × 10(-12) cm(3) molecule(-1) s(-1) with a strong stereoisomer and -OCH3 group position dependence; the (E)-stereoisomers with the -OCH3 group in an α- position relative to the double bond had the greatest reactivity. Rate coefficients measured for the d3-MPHE isomer analogues showed decreased reactivity consistent with a minor contribution of H atom abstraction from the -OCH3 group to the overall reactivity. Estimated atmospheric lifetimes for the MPHE isomers range from days to months. Atmospheric lifetimes, radiative efficiencies, and global warming potentials for these short-lived MPHE isomers were estimated based on the measured OH rate coefficients along with measured and theoretically calculated MPHE infrared absorption spectra. Our results highlight the importance of quantifying the atmospheric impact of individual components in an isomeric mixture.

  14. The Search for a Complex Molecule in a Selected Hot Core Region: A Rigorous Attempt to Confirm trans-Ethyl Methyl Ether toward W51 e1/e2

    CERN Document Server

    Carroll, P Brandon; Blake, Geoffrey A; Apponi, A J; Ziuyrs, L M; Remijan, Anthony

    2014-01-01

    An extensive search has been conducted to confirm transitions of \\textit{trans}-ethyl methyl ether (tEME, C$_2$H$_5$OCH$_3$), toward the high mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory (ARO) at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by \\citet{FuchsSpace}. Additionally, reevaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 - 30 mK, yielding an upper limit of the tEME column density of $\\leq$ 1.5 $\\times$ 10$^{15}$ cm$^{-2}$. This would make tEME at least a factor 2 times less abundant than dimethyl ether (CH$_3$OCH$_3$) toward W51 e1/e2. We also performed an extensive search for this species toward the high mass star forming region Sgr...

  15. Studies on Excess Volume, Viscosity, and Speed of Sound of Binary Mixtures of Methyl Benzoate in Ethers at T=(303.15,308.15, and 313.15 K

    Directory of Open Access Journals (Sweden)

    M. V. Rathnam

    2013-01-01

    Full Text Available Densities, viscosities, and speed of sound have been determined at T = (303.15, 308.15, and 313.15 K for the binary mixtures of methyl benzoate with tetrahydrofuran, 1,4-dioxane, anisole, and butyl vinyl ether over the entire range of composition. Using these measured values, excess volume VE, deviation in viscosities Δη, excess Gibb’s free energy of activation for viscous flow ΔG*E, and deviation in isentropic compressibility Δks have been calculated. These calculated binary data have been fitted to Redlich-Kister equation to determine the appropriate coefficients. The values of excess volume VE and deviation in viscosities Δη are negative over the entire range of composition for all the binary systems at the studied temperatures. The behavior of these parameters with composition of the mixture has been discussed in terms of molecular interactions between the components of liquids.

  16. 用于脱除C5及MTBE中甲醇的渗透汽化膜研究%Study on Pervaporation Membranes for Removing Methanol from C5 or Methyl Tert-butyl Ether Mixtures

    Institute of Scientific and Technical Information of China (English)

    张林; 陈欢林; 周志军; 钱锦文; 高从堦; 潘祖仁

    2003-01-01

    Several pervaporation membranes, cellulose acetate (CA), polyvinylbutyral (PVB), poly(MMA-co-AA),MMA-AA-BA, CA/PVB blend and CA/poly(MMA-co-AA) blend, were prepared, and their pervaporation properties were evaluated by separation of methanol/C5 or methanol/MTBE (methyl tert-butyl ether). The results shows that the CA composite membrane has a high separation performance (flux Jmethanol = 350 g.m-2.h-1 and separation factor α>400) for methanol/C5 mixtures, and the pervaporation characteristics of MMA-AA-BA copolymer membranes changes with the ratio of copolymer. For CA/poly(MMA-co-AA) blend membrane, the pervaporation performance is improved in comparison with CA or poly(MMA-co-AA) membrane. From the experiment of CA/PVB blend membranes for methanol/MTBE mixture, it is found that the compatibility of blends may affect the separation features of blend membrane.

  17. [Preparation and application of the quinonyl chloromethylation polystyrene in biological treatment of wastewater].

    Science.gov (United States)

    Zhang, Hua-Yu; Xu, Qing; Niu, Chun-Mei; Wang, Ya-Jun; Hou, Zheng-Hao; Li, Shao-Ying; Chen, Yan-Ming; Lian, Jing; Wu, Shi-Bin; Guo, Jian-Bo

    2014-05-01

    The technology of non-water-soluble mediator anaerobic biological catalysis has attracted more and more attention in the field of environment technology. In this study, five kinds of quinonly compounds were grafted on the chloromethylation polystyrene macromolecular carrier by Friedel-Crafts reaction. Reaction factors of temperature and molar ratio for the 1,4-naphthoquinone grafting carrier were optimized, and the optimal temperature was 78 degreesC while the optimal molar ratio of 1, 4-naphthoquinone and chloromethylation polystyrene was 2: 1. Fourier infrared spectrum analysis confirmed that the quinone groups were successfully grafted on the macromolecular backbone chloromethylation polystyrene. Catalysis using the five kinds of quinonly materials as non-water-soluble redox mediators enhanced the biological denitrification rate and the decoloration of azo dyes, meanwhile these materials showed good reusability in the biodegradation of azo dye. This study developed a new method for the preparation of quinonly materials and revealed a new field in the technology of mediator catalysis.

  18. Facile synthesis of hypercrosslinked resins via chloromethylation and continuous condensation of simple aryl molecules

    Indian Academy of Sciences (India)

    Xiaoyan Zhang; Qiu Jin; Libo Dai; Siguo Yuan

    2011-07-01

    A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethylation of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these novel resins were characterized with BET, FT–IR and elementary analysis, respectively. The results showed that these novel adsorptive materials possessing abundant crosslinked networks had high specific surface areas (up to 1191.26 m2/g), large pore volumes (0.2–1.4 ml/g), narrow pore size distributions (mainly in the range of micropores and small mesopores).

  19. Novel pathways to 2,5-dimethylfuran via biomass-derived 5-(chloromethyl)furfural.

    Science.gov (United States)

    Dutta, Saikat; Mascal, Mark

    2014-11-01

    2,5-Dimethylfuran (DMF) is one of the most actively pursued biomass-derived chemicals due to the fact that it can serve both as a biofuel and an intermediate for drop-in terephthalate polymers. DMF can be accessed via catalytic hydrogenation of 5-(hydroxymethyl)furfural (HMF), but the difficult accessibility of HMF from cellulosic biomass is a major impediment to the commercial development of such a process. Alternatively, 5-(chloromethyl)furfural (CMF) is freely accessible in high yield directly from raw biomass and is shown here to be efficiently reduced to DMF under mild conditions via simple derivatives (aldimine, acetal).

  20. 40 CFR 721.5585 - 4,4′-(1-methylethylidene)bisphenol, polymer with (chloromethyl)oxirane and a diamine (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 4,4â²-(1-methylethylidene)bisphenol...-methylethylidene)bisphenol, polymer with (chloromethyl)oxirane and a diamine (generic). (a) Chemical substance and...-methylethylidene)bisphenol, polymer with (chloromethyl) oxirane and a diamine (PMN P-97-0916) is subject...

  1. (Vapour + liquid) equilibrium of binary mixtures (1,3-dioxolane or 1,4-dioxane + 2-methyl-1-propanol or 2-methyl-2-propanol) at isobaric conditions[(Vapour+liquid) equilibrium; Cyclic ethers; Butanols; ASOG; UNIFAC

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Antonio; Lafuente, Carlos; Minones, Jose; Kragl, Udo; Royo, Felix M. E-mail: femer@posta.unizar.es

    2004-02-01

    Isobaric (vapour + liquid) equilibrium of (1,3-dioxolane or 1,4-dioxane + 2-methyl-1-propanol or 2-methyl-2-propanol) at 40.0 kPa and 101.3 kPa has been studied with a dynamic recirculating still. The experimental VLE data are thermodynamically consistent. From these data, activity coefficients were calculated and correlated with the Margules, van Laar, Wilson, NRTL and UNIQUAC equations. The VLE results have been compared with the predictions by the UNIFAC and ASOG methods.

  2. Atmospheric lifetimes of selected fluorinated ether compounds

    DEFF Research Database (Denmark)

    Heathfield, A.E.; Anastasi, C.; Pagsberg, Palle Bjørn;

    1998-01-01

    Atmospheric lifetimes have been estimated for a selection of ethers, the latter representing a class of compounds being considered as replacements for chlorofluorocarbons. The estimates are based on laboratory measurements of rate constants for the reaction of the OH radical with the ethers......, and a comparison with the behaviour of methyl chloroform in the atmosphere. The lifetimes for the ethers ranged from a few hours to half a year, significantly lower than those of chlorofluorocarbons and other replacements being considered. (C) 1998 Elsevier Science Ltd. All rights reserved....

  3. Ethyleneglycol ethers (ethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether acetate, diethyleneglycol monomethyl ether, diethyleneglycol monoethyl ether and diethyleneglycol monobutyl ether).

    NARCIS (Netherlands)

    Maclaine Pont, M.A.

    1996-01-01

    The committee recommends the following exposure limits as concentrations in air averaged over 8 hours (8 h TWA): - ethyleneglycol monomethyl ether: 1 mg/m3 (0.3 ppm) - ethyleneglycol monomethyl ether acetate: 1.5 mg/3 (0.3 ppm) - diethyleneglycol monomethyl ether: 45 mg/m3 (9 ppm) - diethyleneglycol

  4. EXPERIMENTAL INVESTIGATIONS OF REAL TIME SECONDARY CO-INJECTION OF WATER – DIETHYL ETHER SOLUTION IN DI-DIESEL ENGINE FUELLED WITH PALM KERNEL METHYL ESTER

    Directory of Open Access Journals (Sweden)

    Y. V. V. SATYANARAYANAMURTHY

    2012-12-01

    Full Text Available In this investigation tests were conducted on single cylinder diesel engine fuelled with neat diesel and biodiesel palm kernel methyl ester as a base line fuel with secondary injection of Water-DEE solution through the inlet manifold. A real time control systems consists of electronic unit pump that delivers 5% to 25% vol. Water-DEE solution through injector tip mounted nearer to the inlet manifold under a pressure of 3 kgf/cm2. NOx emissions reduced to a level of 500 ppm with simultaneous reduction of soot especially for PKME. However for 15% vol. of Water-DEE injection the HC emissions are closely tallying with that of neat diesel. A global overview of the results has shown that the 15% Water-DEE solution is the optimal blend based on performance and emission characteristics.

  5. THE SEARCH FOR A COMPLEX MOLECULE IN A SELECTED HOT CORE REGION: A RIGOROUS ATTEMPT TO CONFIRM TRANS-ETHYL METHYL ETHER TOWARD W51 e1/e2

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, P. Brandon; McGuire, Brett A. [Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Blake, Geoffrey A. [Division of Chemistry and Chemical Engineering and Division Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Apponi, A. J.; Ziurys, L. M. [Departments of Chemistry and Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Remijan, Anthony, E-mail: pcarroll@caltech.edu [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22901-2475 (United States)

    2015-01-20

    An extensive search has been conducted to confirm transitions of trans-ethyl methyl ether (tEME, C{sub 2}H{sub 5}OCH{sub 3}), toward the high-mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by Fuchs et al. Additionally, re-evaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 and 30 mK, yielding an upper limit of the tEME column density of ≤1.5 × 10{sup 15} cm{sup –2}. This would make tEME at least a factor of two times less abundant than dimethyl ether (CH{sub 3}OCH{sub 3}) toward W51 e1/e2. We also performed an extensive search for this species toward the high-mass star forming region Sgr B2(N-LMH) with the National Radio Astronomy Observatory 100 m Green Bank Telescope. No transitions of tEME were detected and we were able to set an upper limit to the tEME column density of ≤4 × 10{sup 14} cm{sup –2} toward this source. Thus, we are able to show that tEME is not a new molecular component of the interstellar medium and that an exacting assessment must be carried out when assigning transitions of new molecular species to astronomical spectra to support the identification of large organic interstellar molecules.

  6. Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane in ionic liquids

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane catalyzed by BF3·OEt2 was carried out in ionic liquids [bmim]BF4 and [bmim]PF6. The influences of BCMO concentration and molar ratio of BCMO/BF3·OEt2 on the molecular weights and yield of PBCMO were investigated. The polymerization in ionic liquids proceed to high conversions, although molecular weights are limited, similar to polymerization in organic solvent such as CH2C12. Follow a viewpoint of green chemistry,we feel ionic liquid [bmim]BF4 is superior to [bmim]PF6. Extracting [bmim]PF6 from the product using organic solvent as extractant limits its advantage as a green reaction media.

  7. Preparation And Lithographic Properties Of Poly(Trimethylsilylmethyl Methacrylate-Co-Chloromethyl Styrene)

    Science.gov (United States)

    Novembre, Anthony E.; Reichmanis, Elsa; Davis, Myrtle

    1986-07-01

    The random copolymer comprised of trimethylsilylmethyl methacrylate (SI) and chloromethyl styrene (CMS) is shown to function as a negative acting e-beam and deep UV resist. The resist is prepared using free radical solution polymerization techniques. Reactivity ratios were calculated using the least squares treatment of Fineman-Ross, and were determined to be 0.49 and 0.54 for SI and CMS, respectively. This material exhibits etching resistance in an 02 reactive ion etching discharge, and is applicable to bileveli pthographic processes. The resist system exhibits an e-beam and deep UV sensitivity (pg. ) equal to 1.95 11C/cm2 and 18mJ/cm2, respectively. The ratio of etching rates of the planarizing layer HPR-206 to this material is 12 to 1 in 02. Preliminary results indicate this system to have submicron resolution capability.

  8. Structures of the gauche conformers of somE substituted dimethyl ethers. Effect of adjacent atom lone pairs on methyl group asymmetry

    Science.gov (United States)

    Boggs, James E.; Altman, Michael; Cordell, Floyd R.; Dai, Yuanfang

    The complete equilibrium structures of CH 3OCH 3 and of the gauche conformers of CH 30CH 2F, HOCH,F, CH,OCH,Cl and CH,OCH,CN have been determined by ab initio gradient computation at the Hartree-Fock, double zeta-plus-polarization level. The very large asymmetries in CH bond distances previously reported from microwave substitution structures are shown to be non-existent in the equilibrium structures and are presumably artifacts. Small differences, different in direction from those reported from the experiments and nearly an order of magnitude smaller in size, do exist. They reflect three factors: (1) a lengthening of a CH bond which is trans to a lone pair on an adjacent atom, (2) a general shortening of CH bonds originating at a carbon atom bearing a highly electronegative substituent, and (3) a specific interaction in which a CX substituent shortens the nearly parallel CH bond on the other methyl group. The last interaction, not previously reported, is mediated by withdrawal of electron density from the oxygen lone pair which is trans to both groups. Other structural features derived from the microwave studies are supported by the new results. Inclusion of polarization functions in the basis set for oxygen is essential for correct determination of the COC angle and the dihedral angles. The dihedral angles of CH 3OCH 2F and HOCH 2F are not correctly determined by the computation even at this level, although the computed values are improved when d functions are used for oxygen and still more by use of two sets of oxygen d functions. Polarization functions on carbon or on fluorine have no effect on the computed torsional angles. There is no problem in computing the correct dihedral angles with the CI or CN derivatives.

  9. Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.

    The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

  10. Solid-phase extraction based on chloromethylated polystyrene magnetic nanospheres followed by gas chromatography with mass spectrometry to determine phthalate esters in beverages.

    Science.gov (United States)

    Cao, Xiaoji; Kong, Qiaoling; Cai, Ruonan; Zhu, Kundan; Ye, Xuemin; Chen, Jiaoyu; Mo, Weimin; Wang, Jianli

    2014-12-01

    An ultrasound-assisted magnetic solid-phase extraction procedure with chloromethylated polystyrene-coated Fe3 O4 nanospheres as magnetic adsorbents has been developed to determine eight phthalate esters (bis(4-methyl-2-pentyl) phthalate, dipentyl phthalate, dihexyl phthalate, benzyl butyl phthalate, bis(2-butoxyethyl) phthalate, dicyclohexyl phthalate, di-n-octyl phthalate, and dinonyl phthalate) simultaneously in beverage samples, in combination with gas chromatography coupled to tandem mass spectrometry for the first time. Several factors related to magnetic solid-phase extraction efficiencies, such as amount of adsorbent, extracting time, ionic strength, and desorption conditions were investigated. The enrichment factors of the method for the eight analytes were over 2482. A good linearity was observed in the range of 10-500 ng/L for bis(2-butoxyethyl) phthalate and 2-500 ng/L for the other phthalate esters with correlation coefficients ranging from 0.9980 to 0.9998. The limits of detection and quantification for the eight phthalate esters were in the range of 0.20-2.90 and 0.67-9.67 ng/L, respectively. The mean recoveries at three spiked levels were 75.8-117.7%, the coefficients of variations were esters in beverage samples.

  11. Limonene ethers from tire pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Stanciulescu, Maria; Ikura, Michio [CANMET Energy Technology Centre, Natural Resources Canada, 1 Haanel Drive, Ottawa, ON (Canada)

    2006-03-01

    Tire pyrolysis oil was produced by EnerVision Inc., Halifax, Canada using the continuous ablative reactor (CAR) system. The tire oil was separated by distillation into several fractions. Naphtha and limonene enriched naphtha were reacted with methanol over different catalysts. Batch experiments were carried out to separate limonene as methyl limonene ethers. Whole tire pyrolysis oil was distilled and the resulting distillates were redistilled to separate the limonene (bp about 176{sup o}C). Vacuum distillation yielded on average 25.5wt% naphtha containing 16.3wt% limonene (average). Redistillation increased the limonene concentration to approximately 32-37wt%. The conversion of limonene (mono-terpene) to limonene ethers (terpenoides) shifted the boiling point of the limonene derivatives out of the naphtha boiling range (IBP -190{sup o}C). This allowed the separation of fragrant limonene ethers from foul smelling naphtha. Alkoxylation reactions were performed mostly using methanol and acidic catalysts. The methyl ether [1-methyl-4-({alpha}-methoxy-isopropyl)-1-cyclohexene] has a boiling point of about 198{sup o}C which is higher than the end boiling point of the naphtha cut. Five heterogeneous catalysts (four zeolites and one ion exchange resin) were tested in a batch reactor. {beta}-Zeolite produced excellent results. The reaction of R-(+)-limonene with methanol in the presence of activated {beta}-zeolite yielded methyl ether, 87.5% at selectivity 89.7% with a maximum of 2h reaction time. Limonene conversion from whole naphtha to ethers was also high. (author)

  12. Application of Ultrasonic Attenuation Measurements in the Studies on Macromolecular Conformational Behaviors--Phase Behavior of the Aqueous Solution of Poly(vinyl methyl ether) Sensitive to Temperature and the Modification of the Behavior by Using Poly(ac

    Institute of Scientific and Technical Information of China (English)

    WANG,Gong-Zheng(王公正); FANG,Yu(房喻); SHANG,Zhi-Yuan(尚志远); ZHANG,Ying(张颖); HU,Dao-Dao(胡道道)

    2004-01-01

    The phase behavior of the aqueous solution of poly(vinyl methyl ether) (PVME) sensitive to temperature and the modification of the behavior by using poly(acrylic acid) (PAA) have been studied by ultrasonic attenuation measurements and fluorescence probe techniques. It has been observed that PVME solution is transparent at room temperature and becomes turbid upon heating. The solution turns clear again as soon as the temperature is decreased to room temperature. The heating and cooling process can be repeated for many times. The phase behavior of the solution sensitive to temperature is attributed to the conformational changes of the polymer. PVME may adopt an open coil conformation at room temperature. With this conformation, the polymer is well miscible with the solvent, water, and thereby the system is a real solution. The polymer may adopt a compact coil conformation when the temperature is higher than a specific value, which is called the LCST (the lower critical solution temperature) of PVME. In this case, the polymer tangles to each other and forms various aggregates, which can scatter incident light and ultrasonic waves greatly, resulting in the phase separation. Introduction of PAA decreases the temperature sensitivity of the phase behavior of the polymer. The nature of the inhibition is attributed to the complexation of PAA with PVME and the strong hydrophilicity of PAA. Results from fluorescence probe studies are in accordance with those from ultrasonic attenuation measurements, indicating again that the ultrasonic attenuation method can be successfully used for the qualitative studies of polymer conformations and complexation between polymers.

  13. 5-(Chloromethyl)furfural is the New HMF: Functionally Equivalent But More Practical in Terms of its Production From Biomass.

    Science.gov (United States)

    Mascal, Mark

    2015-10-26

    5-(Chloromethyl)furfural (CMF) is a disruptive innovation in the biorefinery. Chemically, it is at least as versatile as the well-known HMF but, unlike HMF, it is accessible in high yield directly from cellulosic biomass due to its lipophilicity and stability under acidic conditions, which facilitate isolation. It has a rich derivative chemistry that includes biofuels, renewable polymers, specialty chemicals, and value-added agrochemical and pharmaceutical products.

  14. 水蒸气处理条件对β沸石合成MTBE催化性能的影响%EFFECT OF STEAM TREATING ON REACTIVITY OF ZEOLITE β FOR SYNTHESIS OF METHYL TERTIARY BUTYL ETHER

    Institute of Scientific and Technical Information of China (English)

    王莅; 余少兵; 李永红; 陈洪钫

    2001-01-01

    The catalytic activity of zeolite β by steam treating on the liquid-phase synthesis of methyl tertiary butyl ether(MTBE) from methanol and isobutene was studied in a batch reactor in the temperature range 343~373K at 1.5MPa. A initial molar ratio of 3.73 (methanol/isobutene) was used in experiments. It was shown that the calcination temperature and conditions of steam treatment have a marked influence on the activity for MTBE formation. The optimum treatment conditions by steaming were 350℃ and 3 hours. The pretreatment temperature of 550℃ helps improving conversion of isobutene. Reaction temperature could effect the catalytic characteristics. The maximum activity of different samples was achieve at 90℃. The zeolite β exhibited both high conversion of isobutene and high selectivity to MTBE. The selectivity to MTBE was close to 100% and the highest conversion of isobutene was 92% on optimum conditions.%用水蒸气处理β沸石作催化剂,在100 cm3间歇高压反应器中研究了甲醇与异丁烯合成甲基叔丁基醚的反应。反应条件:温度为70~100℃;压力为1.5 MPa;醇/烯摩尔比为3.73;催化剂用量为2.0 g/mol。结果表明,550℃预处理和350℃、3 h水蒸气处理有利于提高沸石的催化活性;碱性气氛较中性气氛下处理催化活性高;醚化反应的最佳温度为90℃;醚化反应与较强酸中心存在较好的对应关系。

  15. Insect chymotrypsins: chloromethyl ketone inactivation and substrate specificity relative to possible coevolutional adaptation of insects and plants.

    Science.gov (United States)

    Lopes, Adriana R; Sato, Paloma M; Terra, Walter R

    2009-03-01

    Insect digestive chymotrypsins are present in a large variety of insect orders but their substrate specificity still remains unclear. Four insect chymotrypsins from 3 different insect orders (Dictyoptera, Coleoptera, and two Lepidoptera) were isolated using affinity chromatography. Enzymes presented molecular masses in the range of 20 to 31 kDa and pH optima in the range of 7.5 to 10.0. Kinetic characterization using different colorimetric and fluorescent substrates indicated that insect chymotrypsins differ from bovine chymotrypsin in their primary specificity toward small substrates (like N-benzoyl-L-Tyr p-nitroanilide) rather than on their preference for large substrates (exemplified by Succynil-Ala-Ala-Pro-Phe p-nitroanilide). Chloromethyl ketones (TPCK, N- alpha-tosyl-L-Phe chloromethyl ketone and Z-GGF-CK, N- carbobenzoxy-Gly-Gly-Phe-CK) inactivated all chymotrypsins tested. Inactivation rates follow apparent first-order kinetics with variable second order rates (TPCK, 42 to 130 M(-1) s(-1); Z-GGF-CK, 150 to 450 M(-1) s(-1)) that may be remarkably low for S. frugiperda chymotrypsin (TPCK, 6 M(-1) s(-1); Z-GGF-CK, 6.1 M(-1) s(-1)). Homology modelling and sequence alignment showed that in lepidopteran chymotrypsins, differences in the amino acid residues in the neighborhood of the catalytic His 57 may affect its pKa value. This is proposed as the cause of the decrease in His 57 reactivity toward chloromethyl ketones. Such amino acid replacement in the active site is proposed to be an adaptation to the presence of dietary ketones.

  16. (Diethyl ether{1-[2-(1-methyl-1H-imidazol-2-yl-κN3-1,1-diphenylethyl]-(1,2,3,3a,7a-η-indenyl}lithium(I

    Directory of Open Access Journals (Sweden)

    Maxim V. Borzov

    2009-05-01

    Full Text Available In the title compound, [Li(C27H23N2(C4H10O], the Li atom possesses a nearly planar trigonal coordination environment (assuming the cyclopentadienyl ring of the indenyl group occupies one coordination place. The diethyl ether ligand adopts a nearly planar W-type conformation.

  17. (Diethyl ether){1-[2-(1-methyl-1H-imidazol-2-yl-κN)-1,1-diphenyl-ethyl]-(1,2,3,3a,7a-η)-inden-yl}lithium(I).

    Science.gov (United States)

    Sun, Guofeng; Tian, Chong; Nie, Wanli; Borzov, Maxim V

    2009-04-02

    In the title compound, [Li(C(27)H(23)N(2))(C(4)H(10)O)], the Li atom possesses a nearly planar trigonal coordination environment (assuming the cyclo-penta-dienyl ring of the indenyl group occupies one coordination place). The diethyl ether ligand adopts a nearly planar W-type conformation.

  18. Integrated catalytic and electrocatalytic conversion of substituted phenols and diaryl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yang; Chia, Shao H.; Sanyal, Udishnu; Gutierrez, Oliver Y.; Lercher, Johannes A.

    2016-10-17

    Electrocatalytic hydrogenation and catalytic thermal hydrogenation of substituted phenols and diaryl ethers were studied on carbon-supported Rh. For electrocatalytic and catalytic thermal hydrogen addition reactions, the dominant reaction pathway is hydrogenation to cyclic alcohols and cycloalkyl ethers. The presence of substituting methyl or methoxy groups led to lower rates compared to unsubstituted phenol or diphenyl ether. Methoxy or benzyloxy groups, however, undergo C-O bond cleavage via hydrogenolysis and hydrolysis (minor pathway).

  19. IRON(III) NITRATE-CATALYZED FACILE SYNTHESIS OF DIPHENYLMETHYL (DPM) ETHERS FROM ALCOHOLS

    Science.gov (United States)

    Diphenyl methyl (DPM) ethers constitute important structural portion of some pharmaceutical entities and also as protective group for hydroxyl groups in synthetic chemistry. DPM ethers are normally prepared using concentrated acids or base as catalysts, which may result in the fo...

  20. Vinyl ether silicones

    Energy Technology Data Exchange (ETDEWEB)

    Herzig, C.; Dauth, J.; Deubzer, B.; Weis, J. [Wacker-Chemie GmbH, Burghausen (Germany)

    1995-12-01

    Siloxanes with vinyl ether groups are prepared by hydrosilylation reaction of dihydrosiloxanes with divinyl ethers in excess. Different stoichiometry, produces linear copolymers of different viscosities and double bond concentrations always with an active vinyl ether group at each chain end. Polymerisations triggered by UV light were done with mixtures of these compounds and a series of onium salts. Very fast cure is observed even with low doses at 290 nm. V.E. silicones are found to cure essentially quantitative. The comparison with other highly reactive cationic monomers revealed that compounds are among the fastest curing prepolymers in cationic chemistry.

  1. Catalytic oxidation of dimethyl ether

    Science.gov (United States)

    Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

    2016-05-10

    A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

  2. Identification of oxygenated ions in premixed flames of dimethyl ether and oxygen

    DEFF Research Database (Denmark)

    Frøsig Østergaard, L.; Egsgaard, H.; Hammerum, S.

    2003-01-01

    dimethyl ether, (CH3)(2)OH+. The flame-ion m/z 61 is a mixture of the trimethyloxonium ion, (CH3)(3)O+ and lesser amounts of protonated methyl formate and/or protonated ethyl methyl ether. The viability of an ionic mechanism to soot formation for dimethyl ether-oxygen flames is discussed on the background......The structure of characteristic flame-ions in premixed flames of dimethyl ether and oxygen was studied by ion-molecule reactions with ammonia and collision activation with argon. The results obtained show that the flame-ions m/z 45 and m/z 47 are the methoxymethyl cation, CH3OCH2+, and protonated...... of ions present in the dimethyl ether flames and the reactivity of the ions....

  3. RNAi blockage of desoxyhemigossypol-6-OMT decreases the amounts of methylated sesquiterpenoids in transgenic cotton roots

    Science.gov (United States)

    After pathogen attack, plants produce compounds, called phytoalexins that are toxic to microorganisms. In the case of the cotton plant, these include desoxyhemigossypol (dHG), desoxyhemigossypol-6-methyl ether (dMHG), hemigossypol (HG), and hemigossypol-6-methyl ether (MHG), written in the order of...

  4. An ab initio/Rice-Ramsperger-Kassel-Marcus study of the hydrogen-abstraction reactions of methyl ethers, H(3)COCH(3-x)(CH(3))(x), x = 0-2, by OH; mechanism and kinetics.

    Science.gov (United States)

    Zhou, Chong-Wen; Simmie, John M; Curran, Henry J

    2010-07-14

    A theoretical study of the mechanism and kinetics of the H-abstraction reaction from dimethyl (DME), ethylmethyl (EME) and iso-propylmethyl (IPME) ethers by the OH radical has been carried out using the high-level methods CCSD(T)/CBS, G3 and G3MP2BH&H. The computationally less-expensive methods of G3 and G3MP2BH&H yield results for DME within 0.2-0.6 and 0.7-0.9 kcal mol(-1), respectively, of the coupled cluster, CCSD(T), values extrapolated to the basis set limit. So the G3 and G3MP2BH&H methods can be confidently used for the reactions of the higher ethers. A distinction is made between the two different kinds of H-atoms, classified as in/out-of the symmetry plane, and it is found that abstraction from the out-of-plane H-atoms proceeds through a stepwise mechanism involving the formation of a reactant complex in the entrance channel and product complex in the exit channel. The in-plane H-atom abstractions take place through a more direct mechanism and are less competitive. Rate constants of the three reactions have been calculated in the temperature range of 500-3000 K using the Variflex code, based on the weak collision, master equation/microcanonical variational RRKM theory including tunneling corrections. The computed total rate constants (cm(3) mol(-1) s(-1)) have been fitted as follows: k(DME) = 2.74 xT(3.94) exp (1534.2/T), k(EME) = 20.93 xT(3.61) exp (2060.1/T) and k(IPME) = 0.55 xT(3.93) exp (2826.1/T). Expressions of the group rate constants for the three different carbon sites are also provided.

  5. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  6. Radical cation salts induced domino reaction of anilines with enol ethers: Synthesis of 1,2,3,4-tetrahydroquinoline derivatives

    Institute of Scientific and Technical Information of China (English)

    Xiao Dong Jia; Yan Ren; Cong Dde Huo; Wen Juan Wang; Xiang Ning Chen; Qiong Fu; Xi Cun Wang

    2011-01-01

    A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA+ (5 mol%) was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized. Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction, they serve as surrogates of acetaldehyde, producing a series of 2-methyl-4-anilino-1,2,3,4-tetrahydroquinolines. A single electron transfer mechanism was proposed to rationalize the products formation.

  7. Adsorption characteristics of rebaudioside A and stevioside on cross-linked poly(styrene-co-divinylbenzene) macroporous resins functionalized with chloromethyl, amino and phenylboronic acid groups.

    Science.gov (United States)

    Ye, Fayin; Yang, Ruijin; Hua, Xiao; Zhao, Guohua

    2014-09-15

    The adsorptive separation of each steviol glycoside from aqueous solutions by polymeric adsorbents has attracted a lot of interest in recent years. The adsorption properties of chloromethylated cross-linked poly(styrene-co-divinylbenzene) macroporous resins, functionalised with chloromethyl, amino and phenylboronic acid groups, towards rebaudioside A and stevioside were studied. The results revealed that the resins with amino and phenylboronic acid groups preferred to adsorb stevioside rather than rebaudioside A, and their adsorption kinetics fitted a pseudo-second-order model. Isothermal equilibrium curves of rebaudioside A and stevioside showed a good fitness with the Langmuir and Freundlich models. The adsorption of rebaudioside A and stevioside onto resins was a spontaneous and exothermic process as indicated by the negative values in free energy and enthalpy. Results from the resin-packed column demonstrated that an effluent rich in rebaudioside A (purity 98%) was obtained prior to the breakthrough point of stevioside.

  8. Reaction Pathways and Energetics of Etheric C–O Bond Cleavage Catalyzed by Lanthanide Triflates

    Energy Technology Data Exchange (ETDEWEB)

    Assary, Rajeev S.; Atesin, Abdurrahman C.; Li, Zhi; Curtiss, Larry A.; Marks, Tobin J.

    2013-09-06

    Efficient and selective cleavage of etheric C-O bonds is crucial for converting biomass into platform chemicals and liquid transportation fuels. In this contribution, computational methods at the DFT B3LYP level of theory are employed to understand the efficacy of lanthanide triflate catalysts (Ln(OTf)3, Ln = La, Ce, Sm, Gd, Yb, and Lu) in cleaving etheric C-O bonds. In agreement with experiment, the calculations indicate that the reaction pathway for C-O cleavage occurs via a C-H → O-H proton transfer in concert with weakening of the C-O bond of the coordinated ether substrate to ultimately yield a coordinated alkenol. The activation energy for this process falls as the lanthanide ionic radius decreases, reflecting enhanced metal ion electrophilicity. Details of the reaction mechanism for Yb(OTf)3-catalyzed ring opening are explored in depth, and for 1-methyl-d3-butyl phenyl ether, the computed primary kinetic isotope effect of 2.4 is in excellent agreement with experiment (2.7), confirming that etheric ring-opening pathway involves proton transfer from the methyl group alpha to the etheric oxygen atom, which is activated by the electrophilic lanthanide ion. Calculations of the catalytic pathway using eight different ether substrates indicate that the more rapid cleavage of acyclic versus cyclic ethers is largely due to entropic effects, with the former C-O bond scission processes increasing the degrees of freedom/particles as the transition state is approached.

  9. Reactive carbon microspheres prepared by surface-grafting 4-(chloromethyl)phenyltrimethoxysilane for preparing molecularly imprinted polymer

    Science.gov (United States)

    Liu, Weifeng; Zhao, Huijun; Yang, Yongzhen; Liu, Xuguang; Xu, Bingshe

    2013-07-01

    Carbon microspheres (CMSs) were oxidized by a mixture of concentrated sulfuric and nitric acids, and modified by 4-(chloromethyl)phenyltrimethoxysilane to give reactive surface. Then, by adopting the surface molecular imprinting technique, dibenzothiophene (DBT) molecule-imprinted material MIP-DBT/CMSs was prepared with methacrylic acid as functional monomer and ethylene glycol dimethacrylate as crosslinking agent. The binding character of MIP-DBT/CMSs toward DBT was investigated with static method by gas chromatography, using fluorene and biphenyl as the reference substances which are similar to DBT in chemical structure to a certain extent. The effects of reaction time, temperature, and coupling agent concentration during silanization were investigated. The results show that the optimized conditions of silanization were 0.3 g oxidized-CMSs, 5% of CMTMS, 80 °C and 4 h. On the basis of silanized-CMSs, MIP-DBT/CMSs was synthesized. The adsorption results show that MIP-DBT/CMSs possessed strong adsorption ability for DBT. The maximal adsorption amount reached up 88.83 mg/g, in comparison with 44.51 mg/g of the non-imprinted polymer. In addition, MIP-DBT/CMSs exhibited a good selective adsorption capacity for DBT than fluorene (19.86 mg/g) and biphenyl (15.33 mg/g). The adsorption behavior followed the pseudo second order kinetic model. And the Freundlich isotherm was found to describe well the equilibrium adsorption data.

  10. Solid phase extractive preconcentration of uranium(VI) using quinoline-8-ol anchored chloromethylated polymeric resin beads.

    Science.gov (United States)

    Praveen, R S; Metilda, P; Daniel, S; Rao, T Prasada

    2005-10-31

    A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with quinoline-8-ol (HQ). The modified polymeric resin was characterized by FT-IR spectroscopy and elemental analysis. The HQ anchored resin showed superior binding affinity for U(VI) over Th(IV) and La(III). The influence of various physicochemical parameters on the recovery of U(VI) were optimized by both static and dynamic methods. The phase exchange kinetic studies performed for U(VI) revealed that XAD-16. The developed HQ anchored polymeric resin is highly selective as none of the extraneous species were found to have any deleterious effect. Solid phase extraction (SPE) studies performed using HQ anchored polymeric resin offered enrichment factor of 100 and the lowest concentration below which recoveries become non-quantitative is 5mugl(-1). The accuracy of the developed SPE method in conjunction with Arsenazo III procedure was tested by analyzing marine sediment (MESS-3) and soil (IAEA-Soil 7) reference materials. Furthermore, the above procedure has been successfully employed for the analysis of real soil and sediment samples.

  11. Processed Lignin as a Byproduct of the Generation of 5-(Chloromethyl)furfural from Biomass: A Promising New Mesoporous Material.

    Science.gov (United States)

    Budarin, Vitaliy L; Clark, James H; Henschen, Jonatan; Farmer, Thomas J; Macquarrie, Duncan J; Mascal, Mark; Nagaraja, Gundibasappa K; Petchey, Tabitha H M

    2015-12-21

    The lignin by-product of the conversion of lignocellulosic biomass to 5-(chloromethyl)furfural (CMF) has been characterised by thermogravimetric analysis, N2 physisorption porosimetry, attenuated internal reflectance IR spectroscopy, elemental analysis and solid-state NMR spectroscopy. The lignin (LCMF) has a moderate level of mesoporosity before thermal treatment and a surface area of 63 m(2)  g(-1) , which increases dramatically on pyrolysis at temperatures above 400 °C. An assessment of the functionality and textural properties of the material was achieved by analysing LCMF treated thermally over a range of pyrolysis temperatures. Samples were sulfonated to test their potential as heterogeneous acid catalysts in the esterification of levulinic acid. It was shown that unpyrolysed catalysts gave the highest ester yields of up to 93 %. To the best of our knowledge, this is the first example of mesoporous lignin with an appreciable surface area that is produced directly from a bio-refinery process and with further textural modification of the material demonstrated.

  12. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Science.gov (United States)

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Juan, Cristina

    2016-01-01

    Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH), alternariol monomethyl ether (AME), and tentoxin (TEN) are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC) tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME) combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL) by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr) and intermediate reproducibility (RSDR) were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g). PMID:27845716

  13. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Directory of Open Access Journals (Sweden)

    Yelko Rodríguez-Carrasco

    2016-11-01

    Full Text Available Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH, alternariol monomethyl ether (AME, and tentoxin (TEN are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC tandem mass spectrometry (MS/MS detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr and intermediate reproducibility (RSDR were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g.

  14. A versatile pathway to end-functionalized cellulose ethers for click chemistry applications.

    Science.gov (United States)

    Kamitakahara, Hiroshi; Suhara, Ryo; Yamagami, Mao; Kawano, Haruko; Okanishi, Ryoko; Asahi, Tomoyuki; Takano, Toshiyuki

    2016-10-20

    This paper describes a versatile pathway to heterobifunctional/telechelic cellulose ethers, such as tri-O-methyl cellulosyl azide and propargyl tri-O-methyl celluloside, having one free C-4 hydroxyl group attached to the glucosyl residue at the non-reducing end for the use in Huisgen 1,3-dipolar cycloaddition and copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The one-step end-functionalization of cellulose ethers for molecular rod synthesis involves the introduction of two reactive groups at both ends of the cellulose molecule, and can afford linear triblock copolymers via CuAAC and further reactions. We were able to tailor the degree of polymerization of end-functionalized cellulose ethers with controlled amounts of a Lewis acid, namely SnCl4. Chemical structures of the above cellulose ethers and the reaction conditions for controlling molecular length are discussed.

  15. Oxidation of ethyl ether on borate glass: chemiluminescence, mechanism, and development of a sensitive gas sensor.

    Science.gov (United States)

    Hu, Jing; Xu, Kailai; Jia, Yunzhen; Lv, Yi; Li, Yubao; Hou, Xiandeng

    2008-11-01

    A gas sensor was developed by using the chemiluminescence (CL) emission from the oxidation of ethyl ether by oxygen in the air on the surface of borate glass. Theoretical calculation, together with experimental investigation, revealed the main CL reactions: ethyl ether is first oxidized to acetaldehyde and then to acetic acid, during which main luminous intermediates such as CH 3CO (*) are generated and emit light with a peak at 493 nm. At a reaction temperature of 245 degrees C, the overall maximal emission was found at around 460 nm, and the linear range of the CL intensity versus the concentration of ethyl ether was 0.12-51.7 microg mL (-1) ( R = 0.999, n = 7) with a limit of detection (3sigma) of 0.04 microg mL (-1). Interference from foreign substances including alcohol (methanol, ethanol and isopropanol), acetone, ethyl acetate, n-hexane, cyclohexane, dichloromethane, or ether ( n-butyl ether, tetrahydrofuran, propylene oxide, isopropyl ether and methyl tert-butyl ether) was not significant except a minimal signal from n-butyl ether (ethyl ether.

  16. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; James G.C. Shen; Qisheng Ma

    2000-08-31

    A novel 1,2-ethanediol, bis(hydrogen sulfate), disodium salt precursor-based solid acid catalyst with a zirconia substrate was synthesized and demonstrated to have significantly enhanced activity and high selectivity in producing methyl isobutyl ether (MIBE) or isobutene from methanol-isobutanol mixtures. The precursor salt was synthesized and provided by Dr. T. H. Kalantar of the M.E. Pruitt Research Center, Dow Chemical Co., Midland, MI 48674. Molecular modeling of the catalyst synthesis steps and of the alcohol coupling reaction is being carried out. A representation of the methyl transfer from the surface activated methanol molecule (left) to the activated oxygen of the isobutanol molecule (right) to form an ether linkage to yield MIBE is shown.

  17. Convenient procedures for the α-metallation of vinylic ethers and thioethers

    NARCIS (Netherlands)

    Verkruijsse, H.D.; Brandsma, L.; Schleyer, P. von R.

    1987-01-01

    Ethyl vinyl ether H2C=CHOC2H5 and the analogous cyclic vinylic ethers dehydrofuran and 2,3-dihydropyran can be potassiated at −20°C in the α-position with a 1/1/1 molar mixture of BuLi, t-BuOK and TMEDA in hexane. Methyl vinyl sulfide is potassiated very smoothly by a 1/1 molar mixture of BuLi and t

  18. Oil recovery with sulfomethylated poly (lower alkyl vinyl ether/maleic anhydride)

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-05-22

    Lower alkyl vinyl ether e.g., methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, hexyl vinyl ether, is copolymerized conventionally with maleic anhydride, the resulting copolymer is treated with ammonia or ammonium hydroxide to form the partial amide-ammonium salt, and this salt is in turn treated with formaldehyde and thereafter or simultaneously with ammonium or alkali metal salt sulfite (including bisulfites, etc.) to form an at least partially sulfomethylated copolymer. Aqueous solutions of the sulfomethylated copolymer are useful in increasing the viscosity of drive fluids used in the supplemented recovery of petroleum from subterranean formations. In general, enhancing the polyionic character of mobility control agents used in supplemented recovery of petroleum provides enhanced recovery. Achieving this enhancement of polyionic character through use of sulfonate groups provides a mobility control agent with good ability to sustain viscosity in the presence of brine and lime, usually present in the connate waters of petroleum-bearing formations. (7 claims)

  19. High octane ethers from synthesis gas-derived alcohols. Quarterly technical progress report, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.; Feeley, O.C.; Johansson, M.A.

    1993-11-01

    The objective of the proposed research is to synthesize oxygenated fuel ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from coal-derived H{sub 2}/CO/CO{sub 2} synthesis via alcohol mixtures that are rich in methanol and 2-methyl-1-proanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers. Both organic and inorganic catalysts will be investigated, and the better catalysts will be subjected to long term performance studies. The project is divided into the following three tasks: (1) synthesis of high octane ethers from alcohol mixtures containing predominantly methanol and 2-methyl-1-propanol over superacid resins, (2) inorganic catalysts for the synthesis of high octane ethers form alcohols, and (3) long term performance and reaction engineering for scale-up of the alcohols-to-ether process. A summary of technical progress is provided in this report.

  20. Evaluation of thermal gelation behavior of different cellulose ether polymers by rheology

    Science.gov (United States)

    Balaghi, S.; Edelby, Y.; Senge, B.

    2014-05-01

    Hydroxypropylmethylcellulose (HPMC) and Methylcellulose (MC) are cellulose ethers which can be dispersed in water and used as thickeners, emulsifiers, binders, film formers, and water-retention agents due to their hydrophilic and hydrophobic characteristics. In this study, various types of HPMCs, in comparison with two types of MCs were examined. The formed gels of the different cellulose ethers showed specific and various structural formation and network properties. The degree of methylation (Meth.) and hydroxypropylation (HyPr.) affected drastically the heat-induced gelation of the examined cellulose ethers.

  1. Kinetic studies on the etherification of C5-alkenes to fuel ether tame

    OpenAIRE

    Pääkkönen, Päivi

    2003-01-01

    Tertiary ethers are formed in reactions between alcohols and alkenes and are used in reformulated gasoline as octane-enhancing agents. By blending ethers into the gasoline pool, less ground-level ozone is formed and combustion of the gasoline is more efficient as a result of the oxygen boost. The main goal of this research was to study the synthesis of TAME (tert-amyl methyl ether, 2-methoxy-2-methylbutane) and to formulate a kinetic model as precise as possible for process design purpose...

  2. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian;

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high...... amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine...... in ether lipid metabolism and intracellular ether lipid trafficking....

  3. Dimethyl Ether Sector Develops Rapidly

    Institute of Scientific and Technical Information of China (English)

    Zong Yangong

    2007-01-01

    @@ Rapid capacity expansion Dimethyl ether production in China has developed rapidly in recent years. The total capacity of dimethyl ether in China was only 31.8 thousand t/a in 2002, the output was around 20 thousand tons and the operating rate was 63%. The number of producers increased to over 30 in 2006.

  4. Equilibrium and kinetic studies on ligand substitution reactions of chloromethyl(aquo)cobaloxime with aromatic and aliphatic N-donor ligands

    Indian Academy of Sciences (India)

    D Sudarshan Reddy; S Satyanarayana

    2003-06-01

    Equilibria and kinetics of the reactions of chloromethyl(aquo)cobaloxime with histamine, histidine, glycine and ethyl glycine ester were studied as a function of pH at 25°C, 1.0 M ionic strength (KCl) by spectrophotometric techniques. Comparison of equilibrium constants and rate constants tells that the order is Hisdn > Hiamn > Gly > EtGlyest. The rate of substitution of H2O varies with the p of the incoming ligand and nucleophilic participation of the ligand in the transition state. The rate constants and equilibrium constants are correlated to the hardness and softness of the ligands and the Co(III) of cobaloxime.

  5. UV/O3工艺去除甲基叔丁基醚过程中BrO3-的产生与控制%Bromate formation and control in process of removing methyl tert-butyl ether by UV/O3 technology

    Institute of Scientific and Technical Information of China (English)

    赵光宇; 吕锡武; 周易

    2013-01-01

    Bromate is a potential carcinogen and formed in treatment of bromide-containing water using ozone-based technologies.So,the study on bromate formation during removal of organic pollutions is necessary for applying UV/O3 process.The effects of water background,initial MTBE concentration,ozone dosage and dosing method on removal of methyl tert-butyl ether (MTBE) and formation of bromate were studied.Besides,the mechanism of action for ozone dosing method was explored.The results showed that MTBE removal rates obtained by UV/O3 process in ultrapure water and tap water were 93.5 % and 88.67%,and bromate concentration were 18.01 μg · L-1 and 12.13 μg· L-1,respectively,which were higher than the standard value of 10 μg · L-1.The promotion of initial MTBE concentration inhibited bromate formation,but longer reaction time were compulsory since MTBE concentration was required to be lower than proposed concentration of 5 μg · L-1.In this case,bromate formation was eventually enhanced.Increase of ozone dosage was favorable for MTBE removal,but caused decline of the utilization rate of ozone and the promotion of bromate formation.Comparing three ozone dosing methods in which the same ozone dosage of 5 mg · min · L-1 was applied,the highest hydroxyl radical (· OH) exposure and minimum ozone exposure were obtained in the method at ozone concentration of 0.75 mg · L-1 and reaction time of 120 min.Therefore,the concentrations of MTBE and bromate in water both met the standard values after treatment.

  6. pH-sensitive micelles self-assembled from multi-arm star triblock co-polymers poly(ε-caprolactone)-b-poly(2-(diethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) for controlled anticancer drug delivery.

    Science.gov (United States)

    Yang, You Qiang; Zhao, Bin; Li, Zhen Dong; Lin, Wen Jing; Zhang, Can Yang; Guo, Xin Dong; Wang, Ju Fang; Zhang, Li Juan

    2013-08-01

    A series of amphiphilic 4- and 6-armed star triblock co-polymers poly(ε-caprolactone)-b-poly(2-(diethylamino)ethyl methacrylate)-b-poly(poly(ethylene glycol) methyl ether methacrylate) (4/6AS-PCL-b-PDEAEMA-b-PPEGMA) were developed by a combination of ring opening polymerization and continuous activators regenerated by electron transfer atom transfer radical polymerization. The critical micelle concentration values of the star co-polymers in aqueous solution were extremely low (2.2-4.0mgl(-1)), depending on the architecture of the co-polymers. The self-assembled blank and doxorubicin (DOX)-loaded three layer micelles were spherical in shape with an average size of 60-220nm determined by scanning electron microscopy and dynamic light scattering. The in vitro release behavior of DOX from the three layer micelles exhibited pH-dependent properties. The DOX release rate was significantly accelerated by decreasing the pH from 7.4 to 5.0, due to swelling of the micelles at lower pH values caused by the protonation of tertiary amine groups in DEAEMA in the middle layer of the micelles. The in vitro cytotoxicity of DOX-loaded micelles to HepG2 cells suggested that the 4/6AS-PCL-b-PDEAEMA-b-PPEGMA micelles could provide equivalent or even enhanced anticancer activity and bioavailability of DOX and thus a lower dosage is sufficient for the same therapeutic efficacy. The results demonstrate that the pH-sensitive multilayer micelles could have great potential application in delivering hydrophobic anticancer drugs for improved cancer therapy.

  7. Microwave Spectrum of the Ethylmethyl Ether Molecule

    Directory of Open Access Journals (Sweden)

    Kojiro Takagi

    2003-01-01

    Full Text Available We have observed rotational transitions of ethylmethyl ether (CH3CH2OCH3 in the 24-110 GHz frequency range. We newly assigned the transitions of four Q-branch series for J=1-38 with Ka=0-5 and six R-branch series of b-type transitions for J=7-37 with Ka=0-3. All these assigned transitions were observed to be split into two or four components due to the internal rotations of the methyl groups. We analyzed the averaged frequencies of the split components on the basis of the Watson A-reduced Hamiltonian, neglecting the effect of the internal rotations. A total of 122 transitions were fitted to eight molecular parameters to a 1s standard deviation of 24 kHz. The parameters A, B, C and DJ were improved, and DJK, Dk, dJ and dK were determined for the first time.

  8. Platinum(0)-mediated C-O bond activation of ethers via an SN2 mechanism.

    Science.gov (United States)

    Ortuño, Manuel A; Jasim, Nasarella A; Whitwood, Adrian C; Lledós, Agustí; Perutz, Robin N

    2016-11-29

    A computational study of the C(methyl)-O bond activation of fluorinated aryl methyl ethers by a platinum(0) complex Pt(PCyp3)2 (Cyp = cyclopentyl) (N. A. Jasim, R. N. Perutz, B. Procacci and A. C. Whitwood, Chem. Commun., 2014, 50, 3914) demonstrates that the reaction proceeds via an SN2 mechanism. Nucleophilic attack of Pt(0) generates an ion pair consisting of a T-shaped platinum cation with an agostic interaction with a cyclopentyl group and a fluoroaryloxy anion. This ion-pair is converted to a 4-coordinate Pt(ii) product trans-[PtMe(OAr(F))(PCyp3)2]. Structure-reactivity correlations are fully consistent with this mechanism. The Gibbs energy of activation is calculated to be substantially higher for aryl methyl ethers without fluorine substituents and higher still for alkyl methyl ethers. These conclusions are in accord with the experimental results. Further support was obtained in an experimental study of the reaction of Pt(PCy3)2 with 2,3,5,6-tetrafluoro-4-allyloxypyridine yielding the salt of the Pt(η(3)-allyl) cation and the tetrafluoropyridinolate anion [Pt(PCy3)2(η(3)-allyl)][OC5NF4]. The calculated activation energy for this reaction is significantly lower than that for fluorinated aryl methyl ethers.

  9. 21 CFR 172.872 - Methyl ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the...

  10. Direct Dimethyl Ether Synthesis

    Institute of Scientific and Technical Information of China (English)

    Takashi Ogawa; Norio Inoue; Tutomu Shikada; Yotaro Ohno

    2003-01-01

    Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, home heating and cooking,etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production. One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully finished with about 400 tons DME production.

  11. Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, F.

    2005-04-01

    Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

  12. 用氯甲基化脱除焦化苯中噻吩的研究%Study on Removal of Thiophene from Coking Benzene by Chloromethylation

    Institute of Scientific and Technical Information of China (English)

    罗国华; 徐新; 杨春育; 张国英

    2001-01-01

    The method of removal of thiophene in coking benzene and lightbenzene by chloromethylation is studied. The investigation on thiophene to chloromethylation reaction temperature and feedstock blending proportion shows that thiophene in coking benzene can completely convert into thiophene polymer. Under the reaction temperature of 70℃ and under the ratio condition of coking benzene(containing thiophene 1.4g/L)∶ formaldehyde∶ HCl=6∶1∶1, with the agitating time of 3h, the removal efficiency for thiophene in benzene can be up to 100% .%研究了用氯甲基化脱除焦化苯及轻苯中噻吩的方法。通过对噻吩的氯甲基化反应的温度与原料配比的考察表明,焦化苯中的噻吩可完全转化为噻吩聚合物。在反应温度为70℃、焦化苯(含噻吩1.4g/L)∶甲醛∶HCl=6∶1∶1的条件下,搅拌反应3h,苯中的噻吩脱除率可达100%。

  13. Solvent-Induced Crystallization of Poly(ether ether ketone)

    OpenAIRE

    McPeak, Jennifer Lynne

    1999-01-01

    The purpose of this study was learn how the diffusion, swelling, and crystallization processes are coupled during solvent-induced crystallization of poly(ether ether ketone) (PEEK). Unoriented amorphous PEEK films were immersed in aprotic organic liquids at ambient temperature and bulk properties or characteristics were monitored as a function of immersion time. The sorption behavior, Tg and Tm° suppression, crystallinity, and dynamic mechanical response were correlated as a function of sol...

  14. Rearrangements of Cycloalkenyl Aryl Ethers

    Directory of Open Access Journals (Sweden)

    Mercedesz Törincsi

    2016-04-01

    Full Text Available Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.

  15. Glyceryl guaiacol ether – review

    OpenAIRE

    Massone, Flávio; Universidade Estadual Paulista; Luna, Stélio Pacca Loureiro; Universidade Estadual Paulista; Castro, Gladys Bastos; Universidade Estadual Paulista

    1996-01-01

    The history, physical and chemical properties, pharmacodynamics, pharmacokinetics, adverse effects, toxicity, clinical use in wild and domestic species and drug interactions with glyceryl guaiacol ether, an a-glyceryt ether, is presented. Guaiphenesin produces muscle relaxation without affecting diaphragmatic function. Besides muscle relaxation, the drug produces hypocholesterolemia, hypouricemia and has antitussive and expectorant actions, among others. It is a safe agent, but can produce th...

  16. Long term studies on the anaerobic biodegradability of MTBE and other gasoline ethers

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2009-01-01

    Anaerobic biodegradation of methyl tert-butyl ether (MTBE) using electron acceptors such as nitrate, Fe(III), sulfate and bicarbonate, may be more cost effective and feasible compared to aerobic treatment methods, for dealing with the MTBE problem. Currently. there are a few reports in the litera......Anaerobic biodegradation of methyl tert-butyl ether (MTBE) using electron acceptors such as nitrate, Fe(III), sulfate and bicarbonate, may be more cost effective and feasible compared to aerobic treatment methods, for dealing with the MTBE problem. Currently. there are a few reports...... to investigate the anaerobic biodegradability of MTBE and other gasoline ethers. Inoculums collected from various environments were used, along with different electron acceptors. Only one set of the batch experiments showed a 30-60% conversion of MTBE to tert-butyl alcohol under Fe(III)-reducing conditions...

  17. A Study on Antibacterial Activity and Chemical Composition of the Petroleum Ether Extract from Aspergillusniger Mycelia

    Institute of Scientific and Technical Information of China (English)

    Yang; XIAO; Wujuan; LIU; Zhu; LI

    2014-01-01

    In order to develop natural antibacterial agents,the antibacterial activity of Aspergillusnigerxj was investigated.After being cultured in potato dextrose liquid medium liquid medium,mycelia was under heating reflux extraction with 90% ethanol.Removal of ethanol under reduced pressure gave a residue,to which water was added and then extracted with petroleum ether and ethyl acetate.In vacuo evaporation of the solvents yielded three crude extracts.Then the disc diffusion method was used to measure the antibacterial activity of these extracts.The petroleum ether extract with antibacterial activity was separated by silica gel column chromatography method,then separated and identified by GC-MS after been methyl esterified.At the concentration of 50 mg /mL,the petroleum ether extract of mycelia exhibited inhibitory effect against Staphylococcus aureus.The petroleum ether extract from Aspergillusnigerxj mycelia contained natural substances with antibacterial activity and fatty acids are the main constituents in it.

  18. SYNTHESIS AND CRYSTALLIZATION BEHAVIOR OF POLY(ETHER ETHER KETONE ETHER KETONE) (PEEKEK)

    Institute of Scientific and Technical Information of China (English)

    Zhao-bin Qiu; Zhi-shen Mo; Ying-ning Yu; Hong-fang Zhang; Xian-hong Wang

    2000-01-01

    In this paper, the synthesis and crystallization behavior of poly(ether ether ketone ether ketone) (PEEKEK) are reported. PEEKEK was prepared from 4,4'-bis(p-fluorobenzoyl) diphenyl ether (4,4'-FBDE) and hydroquinone along the nucleophilic substitution route. The thermal properties were investigated by using DSC and TGA. The crystallization behavior of PEEKEK under several conditions, i.e., crystallization from the molten state (melt crystallization), crystallization from a quenched sample (cold crystallization) and crystallization induced by exposing glassy sample to methylene chloride (solvent-induced crystallization) has also been investigated. The results show that crystallization of PEEKEK could be induced by the above methods, and no polymorphism was found. The differences in the crystallization of PEEKEK induced by the above methods are seen in their degree of crystallinity.

  19. Synthesis of hydroxylated and methoxylated polybrominated diphenyl ethers

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ke-wen; GAO Li-ping; CAO Jie; YU Hai-wen; ZHANG Zhang

    2009-01-01

    Hydroxylated/methoxylated polybrominated diphenyl ethers (OH/MeO-PBDEs) are not only detected as natural products, but also regarded as metabolites formed from polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants in various materials. The aim of the present study was to synthesize authentic OH-PBDEs and MeO-PBDEs, as reference standards for environmental exploration. Twenty OH-PBDEs and their corresponding MeO-PBDEs containing three to six bromine atoms were synthesized via a trial of reactions including coupling, oxidation, bromination, methylation, etc. The products were characterized by GC-MS and 1H-NMR spectroscopy in the work. As results show, all compounds synthesized were up to 99% on purity and be reqarded as authentic standards for detecting the chemical pollutants in the emvironment.

  20. Design and Enantiopure Synthesis of(R)-2-((2-Oxooxazolidin-5-yl)methyl)isoindoline-1,3-dione: A Key Precursor to Build 2-Oxazolidinone Class of Antibacterial Agents

    OpenAIRE

    Rajesh, T.; P. Suryanarayana Reddy; Manidhar, M.; M. Vijaya Lakshmi; Madhusudhan, G.

    2011-01-01

    A new synthetic method for the preparation of high enantiopure (R)-2-((2-oxooxazolidin-5-yl)methyl)isoindoline-1,3-dione has been developed. The enantiopurity of the obtained (R)-2-((2-oxooxazolidin-5-yl)methyl) isoindoline-1,3-dione is established using chiral high performance liquid chromatography (HPLC) i.e. enantiomeric excess (ee) as 100%. One among the two proposed approaches, is succeeded in preparing enantiopure targeted chiral building block using (R)-2-(chloromethyl)oxirane ((R)...

  1. Solubility parameter of poly(vinyl methyl ether)

    Science.gov (United States)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  2. Low-Temperature Thermodynamics of Fatty Acid Methyl Ethers (FAME)

    Science.gov (United States)

    The most common form of biodiesel is made by transesterification reaction of vegetable oil or fat with methanol. Although biodiesel is attractive as an alternative diesel fuel or extender, depending on its feedstock it may be very susceptible to cause start up and operability problems during cold w...

  3. Luminescent Lariat Aza-Crown Ether

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2010-03-01

    Full Text Available Lariat ethers are interesting recognition motifs in supramolecular chemistry. The synthesis of a luminescent lariat ether with triglycol chain by azide–alkyne (Huisgen cycloaddition is presented.

  4. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  5. Cooperative hydrophobic/hydrophilic interactions in the hydration of dimethyl ether.

    Science.gov (United States)

    Utiramerur, S; Paulaitis, M E

    2010-04-21

    Cooperative interactions in the hydration of dimethyl ether (DME) relative to its purely hydrophobic analog, propane, are analyzed by expressing the free energy of hydration in terms of an "inner-shell" contribution from water molecular packing and chemical association, and an "outer-shell" contribution described by the mean binding energy of the solute to the solution and fluctuations in this binding energy. We find that nonadditive, cooperative interactions associated with strong correlations in the binding energy fluctuations of the methyl groups and ether oxygen play a dominant role in the hydration of DME relative to propane. The electrostatic nature of these interactions is revealed in a multi-Gaussian analysis of hydration substates, which shows that the formation of favorable ether oxygen-water hydrogen bonds is correlated with less favorable methyl group-water interactions, and vice versa. We conclude that the group additive distinction between the hydrophobic hydration of the DME methyl groups and hydrophilic hydration of the ether oxygen is lost in the context of these cooperative interactions. Our results also suggest that the binding energy fluctuations of constituent hydrophobic/hydrophilic groups are more sensitive than local water density fluctuations for characterizing the hydration of heterogeneous interfaces.

  6. Adsorption and reactions of dimethyl and diethyl ethers on Mo 2C/Mo(1 0 0)

    Science.gov (United States)

    Farkas, A. P.; Solymosi, F.

    2008-04-01

    The adsorption, desorption and dissociation of dimethyl ether and diethyl ether on Mo 2C/Mo(1 0 0) have been investigated by work function, thermal desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The adsorption of both molecules at 100 K caused a significant decrease in the work function of the Mo 2C/Mo(1 0 0) surface. In the case of dimethyl ether almost 90% of the adsorbed monolayer desorbed intact with a Tp = 286 K. Another part decomposed to CO ( Tp = 330 and 960 K) and H 2 ( Tp = 330 and 400 K). The desorption of diethyl ether at monolayer occurred with Tp = 256 and 340 K. Another fraction underwent decomposition as indicated by the release of CO ( Tp = 336 and 436 K) and H 2 ( Tp = 400 K). In addition, the formation of ethylene ( Tp = 342 K) and a very small amount of methane ( Tp = 380 K) was also observed. HREEL spectra of both ethers confirmed their molecular adsorption at 100 K. From the spectral changes occurred upon increasing the exposures and in off-specular direction some conclusions were drawn on the bonding of the adsorbed molecules. Analysis of the HREEL spectra of the annealed layers suggested that in the primary steps the adsorbed ethers dissociate to methyl and methoxy (dimethyl ether), and to ethyl and ethoxy (diethyl ether) species, which react further to yield the desorption products.

  7. Synthesis and antitumor activity of 9-methyl-10-hydroxycamptothecin

    Institute of Scientific and Technical Information of China (English)

    Sheng Wang; Yu Yan Li; Qi Dong You

    2008-01-01

    A novel camptothecin analogue, 9-methyl-10-hydroxycamptothecin (4), was unexpectedly synthesized from 10-hydroxycamptothecin in two steps. The key step included an efficient Mannich-type reaction. The overall yield was 47.2%. An ether analogue of 4, 9-methyl-10-benzylaminomethoxycamptothecin (5), was also prepared. These new camptothecin analogues were evaluated for in vitro cytotoxicity against four human cancer cell lines, and exhibited more potent antitumor activities than contrals camptothecin and topotecan against several cancer cells.

  8. DNA Methylation

    OpenAIRE

    Alokail, Majed S.; Alenad, Amal M.

    2015-01-01

    The DNA of E. coli contains 19,120 6-methyladenines and 12,045 5-methylcytosines in addition to the four regular bases and these are formed by the postreplicative action of three DNA methyltransferases. The majority of the methylated bases are formed by the Dam and Dcm methyltransferases encoded by the dam (DNA adenine methyltransferase) and dcm (DNA cytosine methyltransferase) genes. Although not essential, Dam methylation is important for strand discrimination during repair of replication e...

  9. Synthesis of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide – a tailor-made photoinitiator for dental adhesives

    Directory of Open Access Journals (Sweden)

    Norbert Moszner

    2010-03-01

    Full Text Available Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide (WBAPO was synthesized starting from 3-(chloromethyl-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxyethanol. In the second step, 3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride showed an unexpected low thermal stability. Its thermal rearrangement at 180 °C resulted in a fast formation of 3-(chloromethyl-2,4,6-trimethylbenzoic acid 2-(allyloxyethyl ester. In the third step, the acid chloride was reacted with phenylphosphine dilithium with the formation of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine, which was oxidized to WBAPO. The structure of WBAPO was confirmed by 1H NMR, 13C NMR, 31P NMR, and IR spectroscopy, as well as elemental analysis. WBAPO, a yellow liquid, possesses improved solubility in polar solvents and shows UV–vis absorption, and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations.

  10. MoO3-SnO2催化剂上二甲醚低温氧化高选择性制备甲酸甲酯%Low-temperature oxidation of dimethyl ether to methyl formate with high selectivity over MoO3-SnO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    刘广波; 张清德; 韩怡卓; 椿范立; 谭猗生

    2013-01-01

    定向设计并制备了多功能MoO3-SnO2催化剂,在常压连续流动固定床反应器上实现了二甲醚低温氧化高选择性制备甲酸甲酯的过程.考察了机械混合法、共沉淀法及沉淀浸渍法等不同制备方法对催化剂性能的影响.在沉淀浸渍法制备的MoO3-SnO2催化剂上,常压、160℃反应条件下,甲酸甲酯选择性达94.1%,DME转化率也达到了33.9%,并且产物中无COx生成.采用NH3-TPD、CO2-TPD及H2-TPR对催化剂进行了表征,结果表明,表面酸性、碱性及氧化性的不同是造成催化剂反应性能差异的原因.另外,通过采用XRD、Raman及TEM对催化剂结构进行表征发现,晶粒粒径及金属氧化物MoO3的存在状态等结构的差异是造成催化剂活性不同的主要原因.较小晶粒的催化剂和表面存在的低聚态MoO3是致使催化剂活性提高的主要原因.%Low-temperature oxidation of dimethyl ether (DME) to methyl formate (MF) with high selectivity was realized in a continuous flow fixed-bed reactor over the multifunctional MoO3-SnO2 catalysts designed and prepared intentionally. The effect of the preparation methods including mechanical mixing, co-precipitation and co-precipitation-impregnation on the catalyst activity was investigated. The results showed that the selectivity to MF reaches 94.1% at 160℃ over the catalyst prepared by co-precipitation-impregnation, with DME conversion of 33.9% and absence of COx in the products. The results of NH3-TPD, CO2-TPD and H2-TPR characterizations indicated that the catalysts prepared by various methods are also obviously different in the surface acidic, alkaline and redox properties. The results of Raman, XRD and TEM revealed that MoO3 structure and particle sizes have a significant influence on the catalyst activity; small particle size and oligomeric MoO3 may be responsible for the high activity of the MoO3-SnO2 catalysts from co-precipitation-impregnation in the selective oxidation of DME to MF

  11. Surface Heparinization of Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; CHEN Rui-chao; LIU Shu; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer and space arms was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its application to biological fields.PEEK films were surface modified by UV grafting of acrylic acid(AA) to introduce-COOH on PEEK surface.Adipic amine was used as a.space ann to introduce heparin on PEEK surface based on the condensation reaction between -NH2 and -COOH.The modified PEEK(PEEK-COOH,PEEK-NH2 and PEEK-Hep) was characterized by energy-disperse spectroscopy (EDS),X-ray photoelectron spectroscopy(XPS) and water contact angle measurements,which show that heparin was grafted on PEEK surface.The contact angles of modified PEEK films were lower than those of original films,demonstrating a significant improvement of surface hydrophilicity.

  12. ETG举办针对EtherCAT产品提供商的EtherCAT培训

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    随着EtherCAT技术的成功推广,越来越多的中国最终用户对EtherCAT技术及其应用感兴趣,并就EtherCAT产品的需求反馈给相关厂商。同时,EtherCAT的产品供应商将更多的ETherCAT投放到中国市场。因此,这些厂商感到更多更深入地了解EtherCAT技术及相关情况将有助于他们开发相关市场。于是,EtherCAT技术协会中国代表处适时举办针对EtherCAT产品提供商的EtherCAT培训。

  13. High octane ethers from synthesis gas-derived alcohols. Final technical report, September 25, 1990--December 24, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.

    1994-05-01

    The objective of the research was to develop the methodology for the catalytic synthesis of ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from alcohol mixtures that are rich in methanol and 2-methyl-1-propanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers. The last stage of the synthesis involves direct coupling of synthesis gas-derived methanol and isobutanol that has been previously demonstrated by us to occur over superacid catalysts to yield MIBE and smaller amounts of MTBE at moderate pressures and a mixture of methanol and isobutene at low pressures. A wide range of organic resin catalysts and inorganic oxide and zeolite catalysts have been investigated for activity and selectivity in directly coupling alcohols, principally methanol and isobutanol, to form ethers and in the dehydration of isobutanol to isobutene in the presence of methanol. All of these catalysts are strong acids, and it was found that the organic and inorganic catalysts operate in different, but overlapping, temperature ranges, i.e. mainly 60--120{degrees}C for the organic resins and 90--175{degrees}C for the inorganic catalysts. For both types of catalysts, the presence of strong acid centers is required for catalytic activity, as was demonstrated by lack of activity of fully K{sup +} ion exchanged Nafion resin and zirconia prior to being sulfated by treatment with sulfuric acid.

  14. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  15. Anion conductive aromatic block copolymers containing diphenyl ether or sulfide groups for application to alkaline fuel cells.

    Science.gov (United States)

    Yokota, Naoki; Ono, Hideaki; Miyake, Junpei; Nishino, Eriko; Asazawa, Koichiro; Watanabe, Masahiro; Miyatake, Kenji

    2014-10-08

    A novel series of aromatic block copolymers composed of fluorinated phenylene and biphenylene groups and diphenyl ether (QPE-bl-5) or diphenyl sulfide (QPE-bl-6) groups as a scaffold for quaternized ammonium groups is reported. The block copolymers were synthesized via aromatic nucleophilic substitution polycondensation, chloromethylation, quaternization, and ion exchange reactions. The block copolymers were soluble in organic solvents and provided thin and bendable membranes by solution casting. The membranes exhibited well-developed phase-separated morphology based on the hydrophilic/hydrophobic block copolymer structure. The membranes exhibited mechanical stability as confirmed by DMA (dynamic mechanical analyses) and low gas and hydrazine permeability. The QPE-bl-5 membrane with the highest ion exchange capacity (IEC = 2.1 mequiv g(-1)) exhibited high hydroxide ion conductivity (62 mS cm(-1)) in water at 80 °C. A noble metal-free fuel cell was fabricated with the QPE-bl-5 as the membrane and electrode binder. The fuel cell operated with hydrazine as a fuel exhibited a maximum power density of 176 mW cm(-2) at a current density of 451 mA cm(-2).

  16. SIDE CHAIN LIQUID CRYSTALLINE POLYSILOXANES CONTAINING CROWN ETHER AND BENZYL ETHER MOIETIES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.

  17. Formation of H3O+ from alcohols and ethers induced by intense laser fields.

    Science.gov (United States)

    Shirota, Tatsuro; Mano, Narutoshi; Tsuge, Masashi; Hoshina, Kennosuke

    2010-03-15

    The processes of H(3)O(+) production from alcohols (ethanol, 2-propanol, 1-propanol, 2-butanol) and ethers (diethyl ether and ethyl methyl ether), and their deuterium-substituted species, by intense laser fields (800 nm, 100 fs, approximately 1 x 10(14) W/cm) were investigated through time-of-flight (TOF) mass spectrometry. H(3)O(+) formation was observed for all these compounds except for ethyl methyl ether. From the analysis of TOF signals of H((3-n))D(n)O(+) (n = 0, 1, 2, and 3) that have expanding tails with increasing flight time, it has been confirmed that the reaction proceeds through metastable dissociation from the intermediate species C(2)H((5-m))D(m)O(+)(m = 0-5). The common shape of the H((3-n))D(n)O(+) signal profiles contains two major distributions in the time constant, i.e., fast and slow components of production. Ab initio calculations for the isomers and transition states of C(2)H(5)O(+) were also performed, and the observed H((3-n))D(n)O(+) production mechanism has been discussed. In addition, a stable isomer having a complex structure and two isomerization pathways were discovered to contribute to the H(3)O(+) formation process.

  18. Synthesis and characterization of poly(phthalazinone ether nitrile)(PPEN)-polydimethylsiloxane (PDMS)block copolymers

    Institute of Scientific and Technical Information of China (English)

    Li Ming Dong; Gong Xiong Liao; Ming Jing Wang; Xi Gao Jian

    2008-01-01

    Block copolymers with different backbone compositions have been prepared by the condensation of dimethylamino terminated poly(dimethylsiloxane)(PDMS)and hydroquinone terminated poly(phthalazinone ether nitrile)(PPEN)in the presence of chlorobenzene/N-methyl pyrrolidone (NMP)as solvents.The products were characterized by FTIR,1H NMR and gel permeation chromatography.Differential scanning calorimetry analysis indicated that the block copolymers showed separated microphase.

  19. Kinematic Viscosities for Ether + Alkane Mixtures: Experimental Results and UNIFAC-VISCO Parameters

    Science.gov (United States)

    Bandrés, I.; Lahuerta, C.; Villares, A.; Martín, S.; Lafuente, Carlos

    2008-04-01

    Kinematic viscosities for the binary mixtures of diisopropylether, dibutylether or methyl ter-butyl ether with 3-methylpentane, hexane or heptane have been measured at 283.15 K, 298.15 K, and 313.15 K. The experimental values have been correlated by the McAllister equation. Using these results, new UNIFAC-VISCO parameters, Oether-CH2 and Oether-CH3, have been calculated.

  20. Synthesis and in vitro evaluation of new diphenyl ether derivatives as serotonin transporter ligands

    Institute of Scientific and Technical Information of China (English)

    GUO YunHang; CHEN XiangJi; JIA HongMei; DEUTHER-CONRAD Winnie; BRUST Peter; STEINBACH Jorg; VERCOUILLIE Johnny; LIU BoLi

    2008-01-01

    For the development of new ligands as potential imaging agents for the serotonin transporter (SERT), a series of diphenyl ether derivatives have been synthesized, characterized, and evaluated for their in vitro binding affinities to the SERT. Among the above compounds, 2-(2-((dimethylamino)methyl)-4-fluoro-phenoxy)-5-bromobenzenamine (15) and 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-iodobenzene respectively. They can be further labeled with carbon-11, fluorine-18, iodine-123 or bromine-76, and evaluated as useful imaging agents for the SERT. Moreover, the study of the structure-activity relationship (SAR) provides some useful information for the future design of new ligands.

  1. Octachlorodipropyl ether (s-2) mosquito coils are inadequately studied for residential use in Asia and illegal in the United States.

    Science.gov (United States)

    Krieger, Robert I; Dinoff, Travis M; Zhang, Xiaofei

    2003-09-01

    Children and their parents in residences are often protected by insecticides from nuisance and disease-bearing mosquitoes. The annual worldwide consumption of the four major types of residential insecticide products--aerosols, mosquito coils, liquid vaporizers, and vaporizing mats--is in the billions of units. Mosquito coils are burned indoors and outdoors in East Asia and to a limited extent in other parts of the world, including the United States. Coils consist of an insecticide/repellant, organic fillers capable of burning with smoldering, binder, and additives such as synergists, dyes, and fungicide. The number of coil users in China is in the millions. In Indonesia alone, an estimated seven billion coils are purchased annually. Coils containing pyrethroid insecticides, particularly d-allethrin, may contain octachlorodipropyl ether (S-2, S-421) as a synergist or active ingredient. Use of those coils likely exposes children and adults to some level of bis(chloromethyl)ether (BCME). BCME is formed from formaldehyde and hydrogen chloride, combustion products formed from the slow smoldering (about 8 hr/coil) of the mosquito coils. Because BCME is an extremely potent lung carcinogen, the nature and extent of prolonged exposures that recur in homes during the mosquito season in tropical regions must be evaluated with respect to health. In a small analytical study, coils purchased in Indonesia and in the United States contained highly variable amounts of S-2. Some coils that contained S-2 were not labeled, making it impossible for consumers to make an informed decision about coil contents. Mosquito coils containing S-2 are unregistered, and their use is illegal in the United States. Indoor air monitoring under conditions that represent conditions of use in tropical settings and epidemiology to assess health impacts of coil use are essential to permit responsible regulatory decisions regarding continuing S-2 use.

  2. Synthesis and Anti-inflammatory Activity of Some Novel 3-(6-Substituted-1, 3-benzothiazole-2-yl-2-[{(4-substituted phenyl amino} methyl] quinazolines-4 (3H-ones

    Directory of Open Access Journals (Sweden)

    Manish Srivastav

    2009-01-01

    Full Text Available A series of novel 3-(6-substituted-1, 3-benzothiazole-2-yl-2-[{(4-substituted phenyl amino} methyl] quinazolines-4(3H-ones were synthesized by treating 2-(chloromethyl-3-(6-substituted-1, 3-benzothiazole-2-yl quinazoline-4-(3H-one (IIa-d with various substituted amine. The compounds (IIa-d prepared by treating 2-[(chloroacetyl amino] benzoic acid with different 2-amino-6-substituted benzothiazole. Elemental analysis, IR, 1HNMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolines-4-one derivative were investigated for their anti-inflammatory and antibacterial activity.

  3. Bio-based alternative to the diglycidyl ether of bisphenol A with controlled materials properties.

    Science.gov (United States)

    Maiorana, Anthony; Spinella, Stephen; Gross, Richard A

    2015-03-09

    A series of biobased epoxy monomers were prepared from diphenolic acid (DPA) by transforming the free acid into n-alkyl esters and the phenolic hydroxyl groups into diglycidyl ethers. NMR experiments confirmed that the diglycidyl ethers of diphenolates (DGEDP) with methyl and ethyl esters have 6 and 3 mol % of glycidyl ester. Increasing the chain length of DGEDP n-alkyl esters from methyl to n-pentyl resulted in large decreases in epoxy resin viscosity (700-to-11 Pa·s). Storage modulus of DPA epoxy resins, cured with isophorone diamine, also varied with n-alkyl ester chain length (e.g., 3300 and 2100 MPa for the methyl and n-pentyl esters). The alpha transition temperature of the cured materials showed a linear decrease from 158 to 86 °C as the ester length increases. The Young's modulus and tensile strengths were about 1150 and 40 MPa, respectively, for all the cured resins tested (including DGEBA) and varied little as a function of ester length. Degree of cure for the different epoxy resins, determined by FTIR and DSC, closely approached the theoretical maximum. The result of this work demonstrates that diglycidyl ethers of n-alkyl diphenolates represent a new family of biobased liquid epoxy resins that, when cured, have similar properties to those from DGEBA.

  4. Theoretical Study on the Dark Oxidation Reaction Mechanism of Ethers

    Institute of Scientific and Technical Information of China (English)

    WANG Gui-Xiu; ZHU Rong-Xiu; ZHANG Dong-Ju; LIU Cheng-Bu

    2006-01-01

    The dark oxidation reactions of ethers including aether, isopropyl ether, phenyl isopropyl ether, and benzyl isopropyl ether have been studied by using density functional theory calculations. The structures of initial contact charge transfer complexes (CCTCs), transition states and caged radical intermediates have been located at the B3LYP/6-31G (d) level. The bonding nature of ethers with triplet O2 in CCTCs has been analyzed, and the detailed mechanism of dark oxidation reactions of ether is presented clearly.

  5. Carbon-carbon bond cleavage of 1,2-hydroxy ethers b7 vanadium(V) dipicolinate complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Susan K [Los Alamos National Laboratory; Gordon, John C [Los Alamos National Laboratory; Thorn, David L [Los Alamos National Laboratory; Scott, Brian L [Los Alamos National Laboratory; Baker, R Tom [Los Alamos National Laboratory

    2009-01-01

    The development of alternatives to current petroleum-based fuels and chemicals is becoming increasingly important due to concerns over climate change, growing world energy demand, and energy security issues. Using non-food derived biomass to produce renewable feedstocks for chemicals and fuels is a particularly attractive possibility. However, the majority of biomass is in the form of lignocellulose, which is often not fully utilized due to difficulties associated with breaking down both lignin and cellulose. Recently, a number of methods have been reported to transform cellulose directly into more valuable materials such as glucose, sorbitol, 5-(chloromethyl)furfural, and ethylene glycol. Less progress has been made with selective transformations of lignin, which is typically treated in paper and forest industries by kraft pulping (sodium hydroxide/sodium sulfide) or incineration. Our group has begun investigating aerobic oxidative C-C bond cleavage catalyzed by dipicolinate vanadium complexes, with the idea that a selective C-C cleavage reaction of this type could be used to produce valuable chemicals or intermediates from cellulose or lignin. Lignin is a randomized polymer containing methoxylated phenoxy propanol units. A number of different linkages occur naturally; one of the most prevalent is the {beta}-O-4 linkage shown in Figure 1, containing a C-C bond with 1,2-hydroxy ether substituents. While the oxidative C-C bond cleavage of 1,2-diols has been reported for a number of metals, including vanadium, iron, manganese, ruthenium, and polyoxometalate complexes, C-C bond cleavage of 1,2-hydroxy ethers is much less common. We report herein vanadium-mediated cleavage of C-C bonds between alcohol and ether functionalities in several lignin model complexes. In order to explore the scope and potential of vanadium complexes to effect oxidative C-C bond cleavage in 1,2-hydroxy ethers, we examined the reactivity of the lignin model complexes pinacol monomethyl ether (A

  6. Synthesis and Characterization of Poly(ether amide)s Containing Bisphthalazinone and Ether Linkages

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Shou Hai ZHANG; Ming Jing WANG; Qi Zhen LIANG; Xi Gao JIAN

    2005-01-01

    A novel aromatic diacid, 4, 4'-bis[2-(4-carboxyphenyl)phthalazin-1-one-4-yl]-bisphenyl ether Ⅲ, containing bisphthalazinone and ether linkages was prepared from nucleophilic substitution of p-chlorobenzonitrile with the bisphenol-like monomer Ⅰ, followed by alkaline hydrolysis of the intermediate dinitrile Ⅱ. A series of poly(ether amide)s containing bisphthalazinone and ether linkages derived from diacid Ⅲ and aromatic diamines were synthesized by one-step solution condensation polymerization using triphenyl phosphite and pyridine as condensing agents. Moreover, the properties of poly(ether amide)s including thermal stability,solubility and crystallinity were also studied.

  7. 27 CFR 21.108 - Ethyl ether.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  8. An expedient synthesis of linden ether.

    Science.gov (United States)

    Serra, Stefano; Cominetti, Alessandra A

    2014-03-01

    We here describe a comprehensive study on the preparation of the intensive flavor 3,9-epoxy-p-mentha-1,4(8)-diene (1). Key steps of the presented synthesis are the selective addition of MeLi to the keto-ester 7, the regioselective cyclization of the obtained triol to give the ethers 4 and 8 and the selective dehydration of ether 4 through the use of POCI3 and pyridine. It is worth noting that the presented synthesis represents the first expedient and reliable entry to ether 1. Being present in linden honey, 1 is also known as linden ether and it has been regarded as a potential marker for the authentication of the linden honey origin. Therefore, ether 1 can be used as a useful reference standard for the analysis of the natural flavors, as we demonstrated by means of its identification in a sample ofunifloral linden honey.

  9. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Heock-Hoi Kwon; James G. C. Shen; Qisheng Ma; Robert A. Hunsicker; Andrew P. Butler; Scott J. Bollinger

    2003-03-01

    A tungstena-zirconia (WZ) catalyst has been investigated for coupling methanol and isobutanol to unsymmetrical ethers, i.e. methyl isobutyl ether (MIBE) and compared with earlier studied sulfated-zirconia (SZ) and Nafion-H catalysts. In all cases, the ether synthesis mechanism is a dual site S{sub N}2 process involving competitive adsorption of reactants on proximal acid sites. At low reaction temperatures, methylisobutylether (MIBE) is the predominant product. However, at temperatures >135 C the WZ catalyst is very good for dehydration of isobutanol to isobutene. The surface acid sites of the WZ catalyst and a Nafion-H catalyst were diagnosed by high resolution X-ray photoelectron spectroscopy (XPS) of N 1s shifts after adsorption of amines. Using pyridine, ethylenediamine, and triethylamine, it is shown that WZ has heterogeneous strong Broensted acid sites. Theoretical study located the transition state of the alcohol coupling reaction on proximal Broensted acid sites and accounted well for XPS core-level shifts upon surface acid-base interactions. While computations have not been carried out with WZ, it is shown that the SZ catalyst is a slightly stronger acid than CF{sub 3}SO{sub 3}H (a model for Nafion-H) by 1.3-1.4 kcal/mol. A novel sulfated zirconia catalyst having proximal strong Broensted acid sites was synthesized and shown to have significantly enhanced activity and high selectivity in producing MIBE or isobutene from methanol/isobutanol mixtures. The catalyst was prepared by anchoring 1,2-ethanediol bis(hydrogen sulfate) salt precursor onto zirconium hydroxide, followed by calcination to remove the -(CH{sub 2}CH{sub 2})- bridging residues.

  10. Tiny pollutant emissions of a dimethyl ether fuelled engine

    Institute of Scientific and Technical Information of China (English)

    LANG Jing; ZHANG Yu-sheng; ZHOU Xiao-song; WU Hong-wei

    2008-01-01

    Emissions of dimethyl ether (DME) fuelled engines were investigated by orthogonal experiments on a ZS195 diesel engine. The study mainly focused on the tiny pollutant emissions of formaldehyde (CH2O), methyl formate (CH3OCHO) and formic acid (HCOOH). The presence of CH2O, CH3OCHO and HCOOH are proved in the exhaust by gas chromatograph and Fourier transform infrared spectroscopy. The analysis of variance results indicate that the fuel delivery advance angle is the most important factor for CH2O emission. The fuel delivery advance angle and the interaction of injection pressure and nozzle diameter are considerable factors for unburned hydrocarbon (UHC) emission. The mechanism forming tiny pollutants, primarily through CH2O formation, is suggested to be similar to the mechanism forming UHC by DME partial oxidation existing in crevices and boundary zones, and is verified via DME combustion simulation of a multizone chemical kinetic model.

  11. Methyl gallate

    Directory of Open Access Journals (Sweden)

    Silvina Pagola

    2009-02-01

    Full Text Available The crystal structure of the title compound (systematic name: methyl 3,4,5-trihydroxybenzoate, C8H8O5, is composed of essentially planar molecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10 Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intramolecular hydrogen bonds, each molecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network.

  12. Effect of fatty acid methyl esters from plastrum testudinis on proliferation of rat bone mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Yuehua ZHANG; Heping ZENG; Dongfeng CHEN

    2008-01-01

    The ointment of plastrum testudinis was extracted using petroleum ether,ether and dichloromethane sequentially and the extracts were methyl,esteri,fled. The effects on the proliferation of bone marrow mesenchymal stem cells (bMMSCs) were examined by MTT[3,(4,5,dimethylthiazol,2,yl),2,5,diphenyl tetrazolium bromide] assay and flow cytometry analysis. The volatile components of the samples were studied by gas chromatography,mass spectrometry (GC,MS) and high performance liquid chromatography (HPLC). The results show that the methyl,esterified parts can promote the proliferation of stem cells and they all contain palmitic acid methyl ester. Palmitic acid methyl ester can promote proliferation when the concentration was 0.15 μg/μL. It may be concluded that the palmitic acid methyl ester is important for the methyl,esterified parts that have effects on proliferation.

  13. Photopolymerization of Glycerin Triglycidyl Ether Based Systems

    Institute of Scientific and Technical Information of China (English)

    HUANG Biwu; CHEN Yiwang; DENG Qilan

    2008-01-01

    Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate was added to it.Its copolymerization mechanism was confirmed by using DSC analysis.The effect of ethoxylated trimethyol propane triacrylate on the rate of polymerization for glycerin triglycidyl ether was also studied,and the formation of interpenetrating network tightly cross-link was proposed.

  14. 基于FPGA的EtherCAT从站节点开发%FPGA- based Development of EtherCAT Slave Node

    Institute of Scientific and Technical Information of China (English)

    李昆; 杨建武

    2011-01-01

    随着实时工业以太网技术在工业自动化领域的发展和应用,德国倍福公司推出的EtherCAT技术尤其备受瞩目.EtherCAT技术的核心在于EtherCAT通信机制、EtherCAT主站和EtherCAT从站节点.EtherCAT从站节点通常是采用EtherCAT从站控制芯片和从站控制微处理器来设计实现的,对此提出了一种使用FPGA技术开发实现EtherCAT从站节点功能的方法,并验证了方法的可行性.%With the development and application of the real - time industrial Ethernet technology in industrial automation, EtherCAT technology introduced by Beckhoff is especially well received. The core of EtherCAT technology is the EtherCAT communication mechanisms, EtherCAT Master and EtherCAT Slave Node. EtherCAT slave node is usually designed by using EtherCAT slave controller chip and slave control microprocessor chip to achieve its function, this paper presents a method which is using FPGA technology to develop the EtherCAT slave node, and verifies the feasibility of it.

  15. A transferable force field to predict phase equilibria and surface tension of ethers and glycol ethers.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Pérez-Pellitero, Javier; Mackie, Allan D; Malfreyt, Patrice; Boutin, Anne

    2011-09-15

    We propose a new transferable force field to simulate phase equilibrium and interfacial properties of systems involving ethers and glycol ethers. On the basis of the anisotropic united-atom force field, only one new group is introduced: the ether oxygen atom. The optimized Lennard-Jones (LJ) parameters of this atom are identical whatever the molecule simulated (linear ether, branched ether, cyclic ether, aromatic ether, diether, or glycol ether). Accurate predictions are achieved for pure compound saturated properties, critical properties, and surface tensions of the liquid-vapor interface, as well as for pressure-composition binary mixture diagrams. Multifunctional molecules (1,2-dimethoxyethane, 2-methoxyethanol, diethylene glycol) have also been studied using a recently proposed methodology for the calculation of the intramolecular electrostatic energy avoiding the use of additional empirical parameters. This new force field appears transferable for a wide variety of molecules and properties. It is furthermore worth noticing that binary mixtures have been simulated without introducing empirical binary parameters, highlighting also the transferability to mixtures. Hence, this new force field gives future opportunities to simulate complex systems of industrial interest involving molecules with ether functions.

  16. Vacuum condensates and `ether-drift' experiments

    OpenAIRE

    Consoli, M.; Pagano, A.; Pappalardo, L.

    2003-01-01

    The idea of a `condensed' vacuum state is generally accepted in modern elementary particle physics. We argue that this should motivate a new generation of precise `ether-drift' experiments with present-day technology.

  17. Activity relationships for aromatic crown ethers

    CERN Document Server

    Wilson, M J

    1998-01-01

    This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities...

  18. Solubilities of CO2 in some glycol ethers under high pressure by experimental determination and correlation☆

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Zhi Yun; Zhigang Tang; Xia Gui

    2016-01-01

    The binary vapor–liquid equilibrium data of CO2 in diethylene glycol (monomethyl, monoethyl, monobutyl, di-methyl, diethyl, dibutyl) ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method. It was found by contrast that the ether group in solvents can promote the CO2 absorp-tion, but the hydroxyl group will inhibit the CO2 absorption. Furthermore, the solubilities of CO2 showed an up-ward trend with the increasing molecular lengths of absorbents. The experimental data were also correlated with a modified Patel–Teja equation of state (PT EOS) combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.

  19. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, D.C.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds (C20

  20. Thin sulfonated poly(ether ether ketone) films for the dehydration of compressed carbon dioxide

    NARCIS (Netherlands)

    Koziara, B.T.

    2015-01-01

    In this thesis, the properties of thin films from highly sulfonated poly(ether ether ketone) (SPEEK) have been investigated within the context of their application as membranes for the dehydration of compressed carbon dioxide. Spectroscopic ellipsometry has been used as the predominant measurement t

  1. Dipole Moments of Methyl - Substituted Cyclohexanone

    Energy Technology Data Exchange (ETDEWEB)

    Ka, Soo Hyun; Kim, Ji Hyun; Oh, Jung Jin [Sookmyung Women' s University, Seoul (Korea, Republic of)

    2011-01-15

    The microwave spectrum of 3-methylcyclopentanone has been studied and the dipole components Ιμ{sub a}Ι = 2.97(2), Ιμ{sub b}Ι = 1.00(3), Ιμ{sub c}Ι = 0.18(5), and ΙμtotΙ = 3.14(3) D were reported. These were consistent with a twisted-ring conformation with a methyl group in the equatorial position. The conformation of 3-, 4-methyl cyclohexanone in its ground state has been reported to be a chair form with the methyl group in the equatorial position. The resonance enhanced multiphoton ionization (REMPI) method has been applied to methyl- and ethyl- derivatives of cyclohexanone to investigate the various conformers as well as cyclic ketone and cyclic ether including oxygen. The structural information was compared with ab initio density functional theory to calculate not only the structure of cyclohexanone, but the vibrational spectra of isotopomers of cyclohexanone as well. The information was compared with electron diffraction structure and liquid-phase IR spectra.

  2. A convenient method to generate methylated and un-methylated control DNA in methylation studies

    Directory of Open Access Journals (Sweden)

    Mehdi Manoochehri

    2013-09-01

    Full Text Available Methylated and un-methylated control DNA is an important part of DNA methylation studies. Although human and mouse DNA methylation control sets are commercially available, in case of methylation studies on other species such as animals, plants, and bacteria, control sets need to be prepared. In this paper a simple method of generating methylated and un-methylated control DNA is described. Whole genome amplification and enzymatic methylation were performed to generate un-methylated and methylated DNA. The generated DNA were confirmed using methylation sensitive/dependant enzymes, and methylation specific PCR. Control reaction assays confirmed the generated methylated and un-methylated DNA.

  3. De aanwezigheid van methyl tert-butylether (MTBE) in drinkwater en drinkwaterbronnen

    NARCIS (Netherlands)

    Morgenstern PP; Korte GAL de; Hogendoorn EA; Versteegh JFM; LWD; IEM

    2002-01-01

    In 2001 the National Institute for Public Health and the Environment (RIVM) in the Netherlands conducted a drinking water measurement programme in co-operation with the Netherlands Waterworks Association (VEWIN) for methyl tert-butyl ether (MTBE) in drinking water and the corresponding sources. This

  4. EtherCAT协议分析

    Institute of Scientific and Technical Information of China (English)

    杨晓鸿

    2014-01-01

    <正>EtherCAT协议是德国倍福自动化有限公司(Beckhoff Automation GmbH)于2003年提出,并于2005年被定为IEC标准62407;2007年,IEC把EtherCAT协议加到工业现场总线标准61158。一、协议概述为提高通信效率以及实时性,EtherCAT协议的主要思想有两方面。简化协议,协议兼容以太网的MAC层协议,并由纯硬件完成解析,提高处理速度;而其他协议由软件

  5. Measurement of Solubilities of o-Phenylphenol in Petroleum Ether and DDP in Acetone + Water Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Li-sheng; LONG Bing-wen; XIONG You-qing; WU Jun-sheng; KANG Hui-bao

    2006-01-01

    [(6-oxide-6H-dibenze(c, e)(1, 2) oxaphosphorin-6-yl) methyl]-butanedioic acid (DDP) was prepared and characterized. Solubilities of o-phenylphenol(OPP) in petroleum ether and DDP in acetone + water solution were measured by a gravimetrical method. The solubility data of OPP were well correlated using Francis equation. For the solubility of DDP in acetone aqueous solution, it was found that at each fixed temperature there existed a maximum when the acetone mass fraction in the solvent reached a certain concentration. The experiment shows that the fraction is approximately 0.6. The solubility data would be helpful for their industrial crystallization process.

  6. Catalyzed Oxidation of Aromatic Ethers%芳醚的催化氧化反应

    Institute of Scientific and Technical Information of China (English)

    李雪; 张稳稳; 何菱

    2012-01-01

    以取代芳醚为原料,碘苯醋酸酯为氧化剂,二氯甲烷为溶剂,在醋酸铑催化下合成了一系列醌类化合物,其结构经1H NMR,13C NMR和HR-MS确证.%A series of quinone compounds were synthesized by catalyzed oxidation from substituted aromatic ethers using diacetoxyiodobenzene as the oxidant, rhodium acetate as the catalyst and methyl-ene chloride as the solvent. The structures were confirmed by 1H NMR, 13C NMR and MS.

  7. Design, synthesis and hypoglycemic activity of 3-methyl-1-phe nyl-4-{ 4-[ ( 5-m et hyl-2-phenyloxazol-4-yl) methoxy ] benzylene (benzyl) }-2-pyrazol-5-one

    Institute of Scientific and Technical Information of China (English)

    Xing LIU; Yalou WANG; Guanzhong WU; Jiangchuan LI; Xiaoyan WU

    2008-01-01

    Based on the SAR (structure activity relation-ship) of TZDs (thiazolidinediones), 3-methyl-1-phenyl-2-pyrazoline-5-one was selected as a substitute for TZD. Compounds of 3-methyl- 1-phenyl-4- {4-[(5-methyl-2-phe-nyloxazol-4-yl)methoxy]benzylene(benzyl) }-2-pyrazol-5-one were designed and synthesized to find some more hypoglycemic active agents and further investigate the SAR of this class of compounds. Butanedione monoxime reacted with (substituted) benzaldehyde via cyclization and chlorination to give 4-(chloromethyl)-5-methyl-2-phenyloxazole derivatives, which condensed with 4-hydroxybenzaldehyde or vanillin, and was followed by the Knoevenagel reaction with 3-methyl-1-phenyl-2-pyrazol-5-one to give compounds Ⅰa-Ⅰh. Compounds Ⅰa-Ⅰh were hydrogenated with Pd-C to giveⅡa-Ⅱh, and their hypoglycemic activity was evaluated with a glucose oxidase kit and insulin load test on normal mice. Sixteen new target compounds were synthesized. All the com-pounds were characterized by 1H NMR, IR, MS and elemental analysis. The preliminary pharmacological tests show that the compounds have good hypoglycemic activity and can enhance the action of insulin, especially Ib, Id and If.

  8. 40 CFR 721.3435 - Butoxy-substituted ether alkane.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butoxy-substituted ether alkane. 721... Substances § 721.3435 Butoxy-substituted ether alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as butoxy-substituted ether...

  9. Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Han Zhi WANG; Hui LIU; Yuan KOU

    2006-01-01

    Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.

  10. 46 CFR 151.50-42 - Ethyl ether.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ethyl ether. 151.50-42 Section 151.50-42 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-42 Ethyl ether. (a)(1) Gravity tanks... liquid. (g) Precautions shall be taken to prevent the contamination of ethyl ether by strong...

  11. POLYBROMINATED DIPHENYL ETHERS IN SOUTHERN MISSISSIPPI CATFISH

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in a wide variety of consumer products. Concerns surrounding these compounds are primarily due do their ubiquitous presence in the environment as well as in human tissue, such as milk, coupled with evidence indi...

  12. Orphan enzymes in ether lipid metabolism.

    Science.gov (United States)

    Watschinger, Katrin; Werner, Ernst R

    2013-01-01

    Ether lipids are an emerging class of lipids which have so far not been investigated and understood in every detail. They have important roles as membrane components of e.g. lens, brain and testis, and as mediators such as platelet-activating factor. The metabolic enzymes for biosynthesis and degradation have been investigated to some extent. As most involved enzymes are integral membrane proteins they are tricky to handle in biochemical protocols. The sequence of some ether lipid metabolising enzymes has only recently been reported and other sequences still remain obscure. Defined enzymes without assigned sequence are known as orphan enzymes. One of these enzymes with uncharacterised sequence is plasmanylethanolamine desaturase, a key enzyme for the biosynthesis of one of the most abundant phospholipids in our body, the plasmalogens. This review aims to briefly summarise known functions of ether lipids, give an overview on their metabolism including the most prominent members, platelet-activating factor and the plasmalogens. A special focus is set on the description of orphan enzymes in ether lipid metabolism and on the successful strategies how four previous orphans have recently been assigned a sequence. Only one of these four was characterised by classical protein purification and sequencing, whereas the other three required alternative strategies such as bioinformatic candidate gene selection and recombinant expression or development of an inhibitor and multidimensional metabolic profiling.

  13. Dissociation dynamics of methylal

    Energy Technology Data Exchange (ETDEWEB)

    Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P.; Tzannis, A.-P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

  14. Synthesis and in vitro evaluation of new diphenyl ether derivatives as serotonin transporter ligands

    Institute of Scientific and Technical Information of China (English)

    DEUTHER-CONRAD; Winnie; BRUST; Peter; STEINBACH; Jrg; VERCOUILLIE; Johnny

    2008-01-01

    For the development of new ligands as potential imaging agents for the serotonin transporter (SERT),a series of diphenyl ether derivatives have been synthesized,characterized,and evaluated for their in vitro binding affinities to the SERT. Among the above compounds,2-(2-((dimethylamino)methyl)-4-fluoro-phenoxy)-5-bromobenzenamine (15) and 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-iodobenzene amine (16) show high binding affinities for the SERT with Ki values of 0.28 and 0.20 nmol·L-1,respectively. They can be further labeled with carbon-11,fluorine-18,iodine-123 or bromine-76,and evaluated as useful imaging agents for the SERT. Moreover,the study of the structure-activity relationship (SAR) provides some useful information for the future design of new ligands.

  15. Rotational Investigation of the Adducts of Formic Acid with Alcohols, Ethers and Esters

    Science.gov (United States)

    Evangelisti, Luca; Spada, Lorenzo; Li, Weixing; Caminati, Walther

    2016-06-01

    Mixtures of formic acid with methyl alcohol, with isopropyl alcohol, with tert-butyl alcohol, with dimethylether and with isopropylformiate have been supersonically expanded as pulsed jets. The obtained cool plumes have been analyzed by Fourier transform microwave spectroscopy. It has been possible to assign the rotational spectra of the 1:1 adducts of formic acid with tert-butyl alcohol, with dimethyl ether and with isopropylformiate. The conformational shapes and geometries of these adducts, as well as the topologies of their itermolecular hydrogen bonds will be presented. An explanation is given of the failure of the assignments of the rotational spectra of the adducts of formic acid with methyl alcohol and isopropyl alcohol.

  16. Based Design EtherCAT Slave%基于EtherCAT的从站设计

    Institute of Scientific and Technical Information of China (English)

    文辉

    2015-01-01

    Fieldbus has become an important part of the automatic control technology, through a large number of practical experiments and testing, now widely applied. EtherCAT has good real-time capability to adapt to the small amount of data communications, and affordable, the industrial control has been widely used. However, due to EtherCAT Slave design must use a special chip, leading from the station complex hardware design, commissioning difficulties, increasing costs. In this paper, AM3358 Cortex A8 processor plus Ethernet physical layer transceiver (PHY) program, due to the integrated chip inside AM3358 Industrial communications subsystem (PRU-ICSS) EtherCAT protocol can be achieved, so long as the external PHY can become EtherCAT Slave ..%现场总线已经成为自动化控制技术重要组成部分,通过大量的实践实验与测试,如今已经获得广泛的应用。EtherCAT具有良好的实时能力,适应小数据量通信,并且价格经济,在工业控制上得到广泛的应用。但由于EtherCAT从站设计必须使用专门的芯片,导致从站的硬件设计复杂、调试困难、成本增加。文章采用AM3358 Cortex A8处理器外加以太网物理层收发器(PHY)的方案,由于AM3358片内集成工业用通信子系统(PRU-ICSS)可以实现EtherCAT协议,因此只要外加PHY就可以成为EtherCAT从站。

  17. Synthesis of poly(vinyl ether)s with perfluoroalkyl pendant groups

    NARCIS (Netherlands)

    Höpken, Jens; Möller, Martin; Lee, Myongsoo; Percec, Virgil

    1992-01-01

    2-Perfluoro(alkyl)ethyl vinyl ethers, F(CF2)nCH2CH2OCHCH2, (n = 6 or 8), were synthesized and polymerized by means of cationic initiators (HI/ZnI2 and CF3SO3H/(CH3)2S). The perfluorohexyl-substituted poly(vinyl ether) is completely amorphous. The polymer with perfluorooctyl segments shows side chain

  18. Preparation and characterisation of monovalent ion selective cation exchange membranes based on sulphonated poly(ether ether ketone)

    NARCIS (Netherlands)

    Balster, J.; Krupenko, O.; Punt, I.G.M.; Stamatialis, D.; Wessling, M.

    2005-01-01

    This paper analyses the separation properties of various commercial cation exchange membranes (CEMs) and tailor made membranes based on sulphonated poly(ether ether ketone) and poly(ether sulphone) for binary electrolyte solutions containing protons and calcium ions. All membranes are thoroughly cha

  19. Water Ionic Liquid-Crown Ether System Controlling Morphologies and Sizes of Soluble Polypyrrole Nanostructures and Their Self-Assembly Behaviors in the System

    Science.gov (United States)

    Yavari, Issa; Kowsari, Elaheh

    The present study reports a novel chemical route to synthesize different sizes of conducting polypyrrol (ppy) nanoparticles by hydrogen-bonding directionality in the presence of a crown ether, ionic liquid ([octmim]Br, octhyl-methyl imidazulim bromide) and ammonium persulfate in HCl solution. The morphology of the nanoparticle of PPy was confirmed by SEM images. The effects of reaction conditions on the morphology of the resultant ppy nanostructures were studied. The conductivity of the product varied with the mass ratio of aniline monomer to crown ether and IL. The chemical and electronic structures of the ppy nanoparticle were also studied by FT-IR and UV-Vis spectrometry, respectively.

  20. Tween as a Substitute for Diethyl Ether in the Formalin-Ether Sedimentation Technique

    Directory of Open Access Journals (Sweden)

    NA Ahmadi

    2007-10-01

    Full Text Available Background: Tween as a substitute for diethyl ether in the formalin-ether sedimentation technique was evaluated for para­site detection.Methods: Fresh fecal material free of parasites with 10% formalin to prepare standardized specimen was thoroughly pooled. This specimen was divided into 5 equal portions; one was without infection, and each of the others was individually seeded with Entamoeba coli, and Giardia lamblia cysts, ova of Ascaris lumbericoides, and Hymenolepis nana. Six hundred and eighty four slides including 228 stool samples for each of formalin-tween, formalin-ether and direct wet mount proce­dures were examined.Results: The sensitivity of above mentioned procedures were computed 72.1%, 55% and 30 %; their negative predictive value were 69.3%, 58.3% and 47.3%; and their false negative error rate were 27.9%, 45% and 70%, respectively. There were no false-positive results among the 264 specimens previously identified as negative for the presence of intestinal para­sites. Therefore, specificity for each technique was 100%.Conclusion: In the range of our study, formalin-tween method proved to be equivalent to or better than formalin-ether tech­nique in concentrating parasite eggs, and cysts, as well as in maintaining characteristic morphology. Tween is more stable, safer, cheaper, and less flammable than that of ether; and promises to be a useful alternative to ether.

  1. Dimethyl ether oxidation at elevated temperatures (295-600 K).

    Science.gov (United States)

    Rosado-Reyes, Claudette M; Francisco, Joseph S; Szente, Joseph J; Maricq, M Matti; Frøsig Østergaard, Lars

    2005-12-08

    Dimethyl ether (DME) has been proposed for use as an alternative fuel or additive in diesel engines and as a potential fuel in solid oxide fuel cells. The oxidation chemistry of DME is a key element in understanding its role in these applications. The reaction between methoxymethyl radicals and O(2) has been examined over the temperature range 295-600 K and at pressures of 20-200 Torr. This reaction has two product pathways. The first produces methoxymethyl peroxy radicals, while the second produces OH radicals and formaldehyde molecules. Real-time kinetic measurements are made by transient infrared spectroscopy to monitor the yield of three main products-formaldehyde, methyl formate, and formic acid-to determine the branching ratio for the CH(3)OCH(2) + O(2) reaction pathways. The temperature and pressure dependence of this reaction is described by a Lindemann and Arrhenius mechanism. The branching ratio is described by f = 1/(1 + A(T)[M]), where A(T) = (1.6(+2.4)(-1.0) x 10(-20)) exp((1800 +/- 400)/T) cm(3) molecule(-1). The temperature dependent rate constant of the methoxymethyl peroxy radical self-reaction is calculated from the kinetics of the formaldehyde and methyl formate product yields, k(4) = (3.0 +/- 2.1) x 10(-13) exp((700 +/- 250)/T) cm(3) molecule(-1) s(-1). The experimental and kinetics modeling results support a strong preference for the thermal decomposition of alkoxy radicals versus their reaction with O(2) under our laboratory conditions. These characteristics of DME oxidation with respect to temperature and pressure might provide insight into optimizing solid oxide fuel cell operating conditions with DME in the presence of O(2) to maximize power outputs.

  2. Methyltert-butyl Ether (MTBE Degradation by a Microbial Consortium

    Directory of Open Access Journals (Sweden)

    S. B. Mortazavi

    2005-01-01

    Full Text Available Methyl tert-butyl ether (MTBE is added to reformulated gasoline to meet the 1990 Clean Air Act directives. Widespread use of MTBE in gasoline has resulted in groundwater contamination. Because of its undesirable effects on drinking water and ecologically harmful effects, MTBE removal has become a public health and environmental concern. In this study, we have isolated a mixed bacterial culture which is capable of degrading the MTBE as a sole carbon and energy source. This consortium was developed from mixed urban and petrochemical activated sludge after 4 month's enrichment. Enrichment was conducted in batch reactor, fitted with a screw cap and butyl rubber septum. MTBE concentration was measured in head space by gas chromatography. Degradation was determined by MTBE removal. MTBE biodegradation was depended to Dissolved Oxygen (DO concentration and not affected by the changes in concentration of trace element solution or other stimulator Substances. Degradation rates were nearly 1.478 mg MTBE h-1 g-1 (wet biomass and didn't change with MTBE concentration (up 500 mg L-1.

  3. Alkyl ether lipids, ion channels and lipid raft reorganization in cancer therapy.

    Science.gov (United States)

    Jaffrès, Paul-Alain; Gajate, Consuelo; Bouchet, Ana Maria; Couthon-Gourvès, Hélène; Chantôme, Aurélie; Potier-Cartereau, Marie; Besson, Pierre; Bougnoux, Philippe; Mollinedo, Faustino; Vandier, Christophe

    2016-09-01

    Synthetic alkyl lipids, such as the ether lipids edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) and ohmline (1-O-hexadecyl-2-O-methyl-rac-glycero-3-β-lactose), are forming a class of antitumor agents that target cell membranes to induce apoptosis and to decrease cell migration/invasion, leading to the inhibition of tumor and metastasis development. In this review, we present the structure-activity relationship of edelfosine and ohmline, and we point out differences and similarities between these two amphiphilic compounds. We also discuss the mechanisms of action of these synthetic alkyl ether lipids (involving, among other structures and molecules, membrane domains, Fas/CD95 death receptor signaling, and ion channels), and highlight a key role for lipid rafts in the underlying process. The reorganization of lipid raft membrane domains induced by these alkyl lipids affects the function of death receptors and ion channels, thus leading to apoptosis and/or inhibition of cancer cell migration. The possible therapeutic use of these alkyl lipids and the clinical perspectives for these lipids in prevention or/and treatment of tumor development and metastasis are also discussed.

  4. Product study of the photolysis of ketene and ethyl ethynyl ether at 193.3 nm.

    Science.gov (United States)

    Fockenberg, Christopher

    2005-08-18

    The product distributions of the excimer laser photolysis of ketene (CH2CO) and ethyl ethynyl ether (C2H5OCCH) at lambda = 193.3 nm (ArF) were studied using a time-of-flight mass spectrometer (TOFMS) as an analytical tool. Ketene was photolyzed in bath gases consisting of mixtures of He and H2/D2 at various mixing ratios at constant total pressures of 4 Torr and temperature of about 300 K. Singlet methylene (1CH2) produced in the photolysis of ketene was almost instantaneously converted either to triplet methylene (3CH2) or to methyl radicals in collisions with He and H2 or D2. By extrapolating the methyl and methylene signals to zero time after photolysis, initial concentrations of these radicals were obtained. Analyzing the initial 3CH2 and CH3 concentrations as functions of hydrogen-to-helium ratios as well as simulating the observed traces of reactant and product species resulted in 1CH2 + CO (66 +/- 8)%, as the main product channel of the ketene photolysis with smaller contributions from HCCO + H (17 +/- 7)% and 3CH2 + CO (6 +/- 9)%. Hydrogen atoms, acetylene, ethylene, ethyl, and ketenyl radicals, and small amounts of ketene were observed as primary products of the ethyl ethynyl ether photolysis. Quantification of C2H2, C2H4, C2H5, and CH2CO product leads to a HCCO yield of (91 +/- 14)%.

  5. Inhibition of diethyl ether degradation in Rhodococcus sp. strain DEE5151 by glutaraldehyde and ethyl vinyl ether.

    Science.gov (United States)

    Kim, Yong-Hak; Engesser, Karl-Heinrich

    2005-02-15

    Alkyl ether-degrading Rhodococcus sp. strain DEE5151, isolated from activated sewage sludge, has an activity for the oxidation of a variety of alkyl ethers, aralkyl ethers and dibenzyl ether. The whole cell activity for diethyl ether oxidation was effectively inhibited by 2,3-dihydrofurane, ethyl vinyl ether and glutaraldehyde. Glutaraldehyde of less than 30 microM inhibited the activity by a competitive manner with the inhibition constant, K(I) of 7.07+/-1.36 microM. The inhibition type became mixed at higher glutaraldehyde concentrations >30 microM, probably due to the inactivation of the cell activity by the Schiff-base formation. Structurally analogous ethyl vinyl ether inhibited the diethyl ether oxidation activity in a mixed manner with decreasing the apparent maximum oxidation rate, v(max)(app), and increasing the apparent Michaelis-Menten constant, K(M)(app). The mixed type inhibition by ethyl vinyl ether seemed to be introduced not only by the structure similarity with diethyl ether, but also by the reactivity of the vinyl ether with cellular components in the whole cell system.

  6. Amphiphilic Cellulose Ethers Designed for Amorphous Solid Dispersion via Olefin Cross-Metathesis.

    Science.gov (United States)

    Dong, Yifan; Mosquera-Giraldo, Laura I; Taylor, Lynne S; Edgar, Kevin J

    2016-02-01

    The design of cellulose ether-based amphiphiles has been difficult and limited because of the harsh conditions typically required for appending ether moieties to cellulose. Olefin cross-metathesis recently has been shown to be a valuable approach for appending a variety of functional groups to cellulose ethers and esters, provided that an olefin handle for metathesis can be attached. This synthetic pathway gives access to these functional derivatives under very mild conditions and at high efficiency. Modification of ethyl cellulose by metathesis to prepare useful derivatives, for example, for solubility and bioavailability enhancement of drugs by amorphous solid dispersion (ASD), has been limited by the low DS(OH) of commercial ethyl cellulose derivatives. This is problematic because ethyl cellulose is otherwise a very attractive substrate for synthesis of amphiphilic derivatives by olefin metathesis. Herein we explore two methods for opening up this design space for ether-based amphiphiles, for example, permitting synthesis of more hydrophilic derivatives. One approach is to start with the more hydrophilic commercial methyl cellulose, which contains much higher DS(OH) and therefore is better suited for introduction of high DS of olefin metathesis "handles". In another approach, we explored a homogeneous one-pot synthesis methodology from cellulose, where controlled DS of ethyl groups was introduced at the same time as the ω-unsaturated alkyl groups, thereby permitting complete control of DS(OH), DS(Et), and ultimately DS of the functional group added by metathesis. We describe the functionalized derivatives available by these successful approaches. In addition, we explore new methods for reduction of the unsaturation in initial metathesis products to provide robust methods for enhancing product stability against further radical-catalyzed reactions. We demonstrate initial evidence that the products show strong promise as amphiphilic matrix polymers for amorphous

  7. Synthesis of New Liquid Crystalline Diglycidyl Ethers

    Directory of Open Access Journals (Sweden)

    Issam Ahmed Mohammed

    2012-01-01

    Full Text Available The phenolic Schiff bases I–VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia–VIa. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC and polarizing optical microscopy (POM. All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.

  8. Emergent gravity and ether-drift experiments

    CERN Document Server

    Consoli, M

    2009-01-01

    In principle, ether-drift experiments could distinguish phenomenologically emergent-gravity approaches, where an effective curvature emerges from hydrodynamic distortions of the same physical, flat-space vacuum, from the more conventional scenario where curvature is considered a fundamental property of space-time down to extremely small length scales and the speed of light represents a universal constant. From an experimental point of view, in this particular context, besides time modulations that might be induced by the Earth's rotation (and its orbital revolution), one should also consider the possibility of random fluctuations of the signal. These might reflect the stochastic nature of the underlying 'quantum ether' and be erroneously interpreted as mere instrumental noise. To test the present interpretation, we have extracted the mean amplitude of the signal from various experiments with different systematics, operating both at room temperature and in the cryogenic regime. They all give the same consisten...

  9. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

    Science.gov (United States)

    Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

    2009-01-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  10. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada.

    Science.gov (United States)

    Leiker, Thomas J; Abney, Sonja R; Goodbred, Steven L; Rosen, Michael R

    2009-03-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596 microg kg(-1) wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (<51 microg kg(-1) ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  11. Catalytic intermolecular hydroamination of vinyl ethers.

    Science.gov (United States)

    Pahadi, Nirmal K; Tunge, Jon A

    2009-12-01

    This manuscript details the development of a palladium-catalyzed hydroamination of vinyl ethers. It is proposed that palladium catalyzes the hydroamination via Bronsted base catalysis, where palladium is protonated by the relatively acidic sulfonamide to generate a palladium hydride as well as the active anionic sulfonamide nucleophile. Thus, this process is distinct from known palladium-catalyzed hydroaminations of styrene derivatives that utilize less acidic amines.

  12. Fluoroalkylation of aryl ether perfluorocyclobutyl polymers

    OpenAIRE

    Ligon, Clark; Ameduri, Bruno; Boutevin, Bernard; Smith, Dennis

    2008-01-01

    International audience; Post functionalization of aryl ether perfluorocyclobutyl (PFCB) polymers with fluoroalkyl side chains was accomplished with Umemoto's FITS reagents. The fluoroalkylated PFCB polymers (20 % functionalized) showed increases in both hydrophobicity and oleophobicity. Static contact angle for hexadecane was increased after fluoroalkylation from 0° to greater than 30° for the two PFCB polymers tested. Increased oil repellency makes these materials potential candidates for va...

  13. Nikola Tesla, the Ether and his Telautomaton

    Science.gov (United States)

    Milar, Kendall

    2014-03-01

    In the nineteenth century physicists' understanding of the ether changed dramatically. New developments in thermodynamics, energy physics, and electricity and magnetism dictated new properties of the ether. These have traditionally been examined from the perspective of the scientists re-conceptualizing the ether. However Nikola Tesla, a prolific inventor and writer, presents a different picture of nineteenth century physics. Alongside the displays that showcased his inventions he presented alternative interpretations of physical, physiological and even psychical research. This is particularly evident in his telautomaton, a radio remote controlled boat. This invention and Tesla's descriptions of it showcase some of his novel interpretations of physical theories. He offered a perspective on nineteenth century physics that focused on practical application instead of experiment. Sometimes the understanding of physical theories that Tesla reached was counterproductive to his own inventive work; other times he offered new insights. Tesla's utilitarian interpretation of physical theories suggests a more scientifically curious and invested inventor than previously described and a connection between the scientific and inventive communities.

  14. From ether theory to ether theology: Oliver Lodge and the physics of immortality.

    Science.gov (United States)

    Raia, Courtenay Grean

    2007-01-01

    This article follows the development of physicist Oliver Lodge's religio-scientific worldview, beginning with his reticent attraction to metaphysics in the early 1880s to the full formulation of his "ether theology" in the late 1890s. Lodge undertook the study of psychical phenomena such as telepathy, telekinesis, and "ectoplasm" to further his scientific investigations of the ether, speculating that electrical and psychical manifestations were linked phenomena that described the deeper underlying structures of the universe, beneath and beyond matter. For Lodge, to fully understand the ether was to force from the universe an ultimate Revelation, and psychical research, as the most modern and probatory science, was poised to replace religion as the means of that disclosure.

  15. Synthesis of Diaryl Ethers, Diaryl Sulfides, Heteroaryl Ethers and Heteroaryl Sulfides under Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    LI,Feng; ZOU,Jiong; WANG,Quan-Rui; TAO,Feng-Gang

    2004-01-01

    @@ Diaryl ether moiety is found in a pool of naturally occurring and medicinally important compounds.[1] As a consequent, considerable efforts have been devoted to the assembly of this framework.[2] Recently, we have developed a microwave heating version of the synthesis of diaryl ethers as well as aryl sulfides. Under our conditions, even the extremely electron-poor 4-nitrophenol works well and its reaction with 1-halo-4-nitrobenzenes produces 4-(nitrophenoxy)-benzonitriles in satisfactory yield. The scope of the present protocol has been expanded to hydroxylated six-membered heterocycles as well as 2-pyrimidinethiol with mildly activated aryl halides, affording heteroaryl ethers and respectively sulfides. The advantages of the present method include the wide substrate scope, no use of any metal catalysts, the ease of product isolation and high yields.

  16. Effect of degree of sulfonation and casting solvent on sulfonated poly(ether ether ketone) membrane for vanadium redox flow battery

    Science.gov (United States)

    Xi, Jingyu; Li, Zhaohua; Yu, Lihong; Yin, Bibo; Wang, Lei; Liu, Le; Qiu, Xinping; Chen, Liquan

    2015-07-01

    The properties of sulfonated poly(ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) and casting solvent are investigated for vanadium redox flow battery (VRFB). The optimum DS of SPEEK membrane is firstly confirmed by various characterizations such as physicochemical properties, ion selectivity, and VRFB single-cell performance. Subsequently the optimum casting solvent is selected for the optimum DS SPEEK membrane within N,N‧-dimethylformamide (DMF), N,N‧-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO). The different performance of SPEEK membranes prepared with various casting solvents can be attributed to the different interaction between solvent and -SO3H group of SPEEK. In the VRFB single-cell test, the optimum SPEEK membrane with DS of 67% and casting solvent of DMF (S67-DMF membrane) exhibits higher VRFB efficiencies and better cycle-life performance at 80 mA cm-2. The investigation of various DS and casting solvent will be effective guidance on the selection and modification of SPEEK membrane towards VRFB application.

  17. 76 FR 38026 - Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-06-29

    ... butyl ether, also a glycol ether differing in only one ethyl group from DEGBE. These data were used to... monobutyl ether, also a glycol ether differing only in one ethyl group. This data was used to assess the... AGENCY 40 CFR Part 180 Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a...

  18. Methyl Anthranilate as a Repellent for Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bernklau, E J; Hibbard, B E; Norton, A P; Bjostad, L B

    2016-08-01

    Methyl anthranilate was identified as the active compound in extracts of maize (Zea mays L.) roots that were shown to be repellent to neonate western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae. A bioassay-driven approach was used to isolate the active material from diethyl ether extracts of roots from germinating maize seeds. Separation of the extract on a Florisil column yielded an active fraction of 90:10 hexane:diethyl ether. Analysis with gas chromatography-mass spectrometry identified two compounds in the active fraction: indole (2,3-benzopyrrole) and methyl anthranilate (methyl 2-aminobenzoate). When tested in behavioral bioassays, methyl anthranilate elicited a significant (P repellent response at doses of 1, 10, and 100 µg. In subsequent single-choice bioassays, 1, 10, and 100 µg of methyl anthranilate prevented larvae from approaching 10 mmol/mol concentrations of carbon dioxide, which is normally highly attractive to the larvae. Indole, the other compound identified from the active fraction, did not elicit a behavioral response by the larvae. Methyl anthranilate has potential for development as a management tool for western corn rootworm larvae and may be best suited for use in a push-pull control strategy.

  19. [DNA methylation and epigenetics].

    Science.gov (United States)

    Vaniushin, B F

    2006-09-01

    In eukaryotic cells, nuclear DNA is subject to enzymatic methylation with the formation of 5-methylcytosine residues, mostly within the CG and CNG sequences. In plants and animals this DNA methylation is species-, tissue-, and organelle-specific. It changes (decreases) with age and is regulated by hormones. On the other hand, genome methylation can control hormonal signal. Replicative and post-replicative DNA methylation types are distinguished. They are mediated by multiple DNA methyltransferases with different site-specificity. Replication is accompanied by the appearance of hemimethylated DNA sites. Pronounced asymmetry of the DNA strand methylation disappears to the end of the cell cycle. A model of methylation-regulated DNA replication is proposed. DNA methylation controls all genetic processes in the cell (replication, transcription, DNA repair, recombination, and gene transposition). It is the mechanism of cell differentiation, gene discrimination and silencing. In animals, suppression of DNA methylation stops development (embryogenesis), switches on apoptosis, and is usually lethal. Disruption of DNA methylation pattern results in the malignant cell transformation and serves as one of the early diagnostic features of carcinogenesis. In malignant cell the pattern of DNA methylation, as well as the set of DNA methyltransferase activities, differs from that in normal cell. In plants inhibition of DNA methylation is accompanied by the induction of seed storage and florescence genes. In eukaryotes one and the same gene can be simultaneously methylated both at cytosine and adenine residues. It can be thus suggested, that the plant cell contains at least two different, and probably, interdependent systems of DNA methylation. The first eukaryotic adenine DNA methyltransferase was isolated from plants. This enzyme methylates DNA with the formation of N6-methyladenine residues in the sequence TGATCA (TGATCA-->TGm6ATCA). Plants possess AdoMet-dependent endonucleases

  20. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  1. 我国纤维素醚市场调查及需求预测%Market Research and Supply and Demand Forecast of Cellulose Ether in China

    Institute of Scientific and Technical Information of China (English)

    卜新平

    2011-01-01

    The general situation of production and consumption of cellulose ether, especially for caroboxylic methyl cellulose, methyl cellulose and derivatives are introduced. The demand and supply trend is also forecasted. Competition factors and problem in cellulose ether industry are analyzed and gives some suggestions on the domestic production.%重点介绍羟甲基纤维素和甲基纤维素及其衍生物的生产和消费情况,并对市场需求进行了预测。还对纤维素醚的行业竞争因素和存在的问题进行了分析。

  2. SYNTHESIS OF POLY ( ETHER-URETHANE) CONTAINING PENDANT AMINO GROUP

    Institute of Scientific and Technical Information of China (English)

    WU Jinhuang; SUN Yanhui; FENG Xinde

    1989-01-01

    This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.

  3. Phenolic ethers in the organic polymer of the Murchison meteorite

    Science.gov (United States)

    Hayatsu, R.; Winans, R. E.; Scott, R. G.; McBeth, R. L.; Moore, L. P.; Studier, M. H.

    1980-03-01

    Results of the oxidation of the organic polymer of the Murchison meteorite with alkaline cupric oxide, a mild-oxidant specific for cleaving ether linkages, are reported. Qualitative analyses by gas chromatography-mass spectrometry, solid-probe mass spectrometry and high-resolution mass spectrometry reveal the presence of large amounts of meta-hydroxybenzoic acid and 3-hydroxy-1,5-benzenedicarboxylic acid, along with seven phenolic acids, in the oxidized solution, indicating the presence of phenolic ethers and of aryl alkyl ethers having no nuclear hydroxy group in the meteorite. The formation of phenolic ethers in the solar nebula by Fischer-Tropsch type reactions is then discussed.

  4. Alcohol dehydration: Mechanism of ether formation using an alumina catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shi, B.; Davis, B.H. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-01

    Ether formation during the dehydration of secondary alcohols, namely, 2-butanol, 3-pentanol, and 1-cyclopentylethanol, was investigated. Using the proper reaction conditions, the yield of di-2-butyl ether during the dehydration of 2-butanol on alumina can be as high as 40%. That ether is formed by adding an alcohol to the alkene is ruled out by the results from deuterium tracer studies. Results from experiments using S(+)- 2-butanol suggest that the formation of di-2-butyl ether occurs by a S{sub N}2-type mechanism. 33 refs., 5 figs., 3 tabs.

  5. Theoretical calculation on a compound formed by methyl alcohol and simmondsin

    Directory of Open Access Journals (Sweden)

    İzzet KARA

    2016-12-01

    Full Text Available Etheric oil results from the esterification reactions of oil acids with alcohols. In these reactions, one molecule water (H2O is composed of H× protons from oil acids and OH- groups which separated from alcohol. Etheric oil is commonly used in food industry, perfume industry and medicine. From this perspective, we need to know physical properties of etheric oil as well as chemical properties. In this study, the highest occupied molecular orbital (HOMO energies, the lowest unoccupied molecular orbital (LUMO energies, the electronic properties (total energy, electronegativity, chemical hardness and softness, NBO analysis and thermodynamic parameters of a compound formed by methyl alcohol and simmondsin have been performed by using Gaussian 09W program. The structural and spectroscopic data of the molecule in the ground state have been calculated by using density functional method (DFT/B3LYP with the 6-31++G(d,p basis set.

  6. Deriving Biomonitoring Equivalents for selected E- and P-series glycol ethers for public health risk assessment.

    Science.gov (United States)

    Poet, Torka; Ball, Nicholas; Hays, Sean M

    2016-01-01

    Glycol ethers are a widely used class of solvents that may lead to both workplace and general population exposures. Biomonitoring studies are available that have quantified glycol ethers or their metabolites in blood and/or urine amongst exposed populations. These biomonitoring levels indicate exposures to the glycol ethers, but do not by themselves indicate a health hazard risk. Biomonitoring Equivalents (BEs) have been created to provide the ability to interpret human biomonitoring data in a public health risk context. The BE is defined as the concentration of a chemical or metabolite in a biological fluid (blood or urine) that is consistent with exposures at a regulatory derived safe exposure limit, such as a tolerable daily intake (TDI). In this exercise, we derived BEs for general population exposures for selected E- and P-series glycol ethers based on their respective derived no effect levels (DNELs). Selected DNELs have been derived as part of respective Registration, Evaluation, Authorisation and Regulation of Chemicals (REACh) regulation dossiers in the EU. The BEs derived here are unique in the sense that they are the first BEs derived for urinary excretion of compounds following inhalation exposures. The urinary mass excretion fractions (Fue) of the acetic acid metabolites for the E-series GEs range from approximately 0.2 to 0.7. The Fues for the excretion of the parent P-series GEs range from approximately 0.1 to 0.2, with the exception of propylene glycol methyl ether and its acetate (Fue = 0.004). Despite the narrow range of Fues, the BEs exhibit a larger range, resulting from the larger range in DNELs across GEs. The BEs derived here can be used to interpret human biomonitoring data for inhalation exposures to GEs amongst the general population.

  7. Novel high T{sub g} high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4{prime}-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 {times} 10{sup 5} g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T{sub g}) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl{sub 3}, THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  8. Novel high T[sub g] high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. (Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe)

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4[prime]-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 [times] 10[sup 5] g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T[sub g]) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl[sub 3], THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  9. Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

    2013-10-01

    Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

  10. 75 FR 28804 - An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs)

    Science.gov (United States)

    2010-05-24

    ... AGENCY An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs) AGENCY: Environmental Protection...'s 2006 Polybrominated Diphenyl Ethers (PBDEs) Project Plan. This document ] provides an assessment of the exposure of Americans to polybrominated diphenyl ethers (PBDEs), a class of brominated...

  11. 2-Chloro-N-methyl-N-[2-(methylaminophenyl]acetamide

    Directory of Open Access Journals (Sweden)

    Yu-Bin Bai

    2013-02-01

    Full Text Available The title compound, C10H13ClN2O, was obtained as a by-product in the reaction of 2-chloromethyl-1H-benzimidazole, dimethyl sulfate and toluene to synthesise 2-chloromethyl-1-methylbenzimidazole. The dihedral angle between the benzene ring and the acetamide group is 89.72  (6° while that between the aromatic ring and the chloracetyl group is 84.40 (4°. In the crystal, adjacent molecules are linked by pairs of N—H...O hydrogen bonds into inversion dimers.

  12. Application of simplified PC-SAFT to glycol ethers

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2012-01-01

    The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2-e...

  13. Characterization of Poly(ether)urethanes - High Resolution Thermogravimetric Analysis

    Science.gov (United States)

    2004-02-01

    ether)urethanes.11 Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis .......................... 14 viii DRDC Atlantic...Stepwise isothermal plots for the six poly(ether)urethanes. Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis . SAMPLE/ % WT LOSS

  14. Novel class of amino acid antagonists at non-N-methyl-D-aspartic acid excitatory amino acid receptors. Synthesis, in vitro and in vivo pharmacology, and neuroprotection

    Energy Technology Data Exchange (ETDEWEB)

    Krogsgaard-Larsen, P.; Ferkany, J.W.; Nielsen, E.O.; Madsen, U.; Ebert, B.; Johansen, J.S.; Diemer, N.H.; Bruhn, T.; Beattie, D.T.; Curtis, D.R. (Royal Danish School of Pharmacy, Copenhagen (Denmark))

    1991-01-01

    The isoxazole amino acid 2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl) propionic acid (AMPA) (1), which is a highly selective agonist at the AMPA subtype of excitatory amino acid (EAA) receptors, has been used as a lead for the development of two novel EAA receptor antagonists. One of the compounds, 2-amino-3-(3-(carboxymethoxy)-5-methylisoxazol-4-yl)propionic acid (AMOA, 7), was synthesized via O-alkylation by ethyl chloroacetate of the amino acid protected AMPA derivative 4. The other compound, 2-amino-3-(2-(3-hydroxy-5-methylisoxazol-4-yl)-methyl-5-methyl-3-+ ++oxoisoxazolin -4-yl)propionic acid (AMNH, 14) was synthesized with use of 4-(chloromethyl)-3-methoxy-5-methylisoxazole (8) as the starting material. The intermediate 4-(chloromethyl)-2-(3-methoxy-5-methylisoxazol-4-yl)methyl-5-me thylisoxazolin- 3-one (11) was converted into the acetamidomalonate (12), which was stepwise deprotected to give 14. Compounds 7 and 14 were stable in aqueous solution at pH values close to physiological pH. Neither 7 nor 14 showed detectable affinities for the receptor, ion channel, or modulatory sites of the N-methyl-D-aspartic acid (NMDA) receptor complex. Quantitative receptor autoradiographic and conventional binding techniques were used to study the affinities of 7 and 14 for non-NMDA receptor sites. Both compounds were inhibitors of the binding of (3H)AMPA (IC50 = 90 and 29 microM, respectively). Compounds 14 and 7 were both very weak inhibitors of the high-affinity binding of radioactive kainic acid ((3H)KAIN). Compound 14, but not 7, was, however, shown to be an inhibitor of low-affinity (3H)KAIN binding as determined in the presence of 100 mM calcium chloride. In the rat cortical slice preparation, 7 was shown to antagonize excitation induced by 1 with some selectivity, whereas 14 proved to be a rather selective antagonist of KAIN-induced excitation.

  15. Exploring chiral separation of 3-carboxamido-5-aryl isoxazole derivatives by supercritical fluid chromatography on amylose and cellulose tris dimethyl- and chloromethyl phenylcarbamate polysaccharide based stationary phases.

    Science.gov (United States)

    Zehani, Yasmine; Lemaire, Lucas; Ghinet, Alina; Millet, Régis; Chavatte, Philippe; Vaccher, Claude; Lipka, Emmanuelle

    2016-10-07

    Four polysaccharide based chiral stationary phases were chosen, two chlorinated: Lux™ Amylose-2 (tris-5-chloro-2-methylphenylcarbamate of amylose) and Lux™ Cellulose-2 (tris-3-chloro-4-methylphenylcarbamate of cellulose) and two methylated: Chiralpak(®) AD-H (tris-3,5-dimethylphenylcarbamate of amylose) and Chiralcel(®) OD-H (tris-3,5-dimethylphenylcarbamate of cellulose) to separate four 3-carboxamido-5-aryl isoxazole derivatives by supercritical fluid chromatography. The effect of chiral stationary phase, co-solvent nature (MeOH, EtOH, 2-PrOH and ACN) and percentage (10-20%), temperature (20-45°C) and chemical structure of the compounds on retention, resolution and elution order were thoroughly studied. In addition, thermodynamic parameters were determined from the linear portion of the Van't Hoff plots. For all the derivatives, the Lux™ Cellulose-2 and Chiralpak(®) AD-H provided excellent resolutions (Rs=9.78) in short run time (under 6min). The preparation of about 10mg of each of the eight enantiomers was achieved successfully on a Chiralpak(®) AD-H with various percentages of ethanol as a co-solvent. Lastly, the enantiomeric purity of each of the eight individual enantiomer generated was determined and found higher than 98%.

  16. O-methylation of natural phenolic compounds based on green chemistry using dimethyl carbonate

    Science.gov (United States)

    Prakoso, N. I.; Pangestu, P. H.; Wahyuningsih, T. D.

    2016-02-01

    The alkyl aryl ether compounds, of which methyl eugenol and veratraldehyde are the simplest intermediates can be synthesized by reacting eugenol and vanillin with the green reagent dimethyl carbonate (DMC). The reaction was carried out under mild of temperature and pressure. Excellent yields and selective products were obtained (95-96%) after a few hours. In the end of the reaction, the catalysts (base and Phase Transfer Catalyst) can be recovered and regenerated.

  17. A New Route to Preparations of Silyl Ethers by Reactions of Silyl Triflimides with Alcohol or Ether

    Institute of Scientific and Technical Information of China (English)

    TANG Zi-Long

    2008-01-01

    A few of acyclic and cyclic silyl ethers were firstly synthesized in good yields by reactions of silyl triflimides with alcohol or ether. The corresponding silyl triflimides were easily produced by protodesilylation of phenyl or allyl silanes with HNTf2. All new compounds were characterized by 1H NMR, 13C NMR, MS, IR and HRMS.

  18. ENZYMOLOGY OF ARSENIC METHYLATION

    Science.gov (United States)

    Enzymology of Arsenic MethylationDavid J. Thomas, Pharmacokinetics Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park...

  19. Lysine methylation: beyond histones

    Institute of Scientific and Technical Information of China (English)

    Xi Zhang; Hong Wen; Xiaobing Shi

    2012-01-01

    Posttranslational modifications (PTMs) of histone proteins,such as acetylation,methylation,phosphorylation,and ubiquitylation,play essential roles in regulating chromatin dynamics.Combinations of different modifications on the histone proteins,termed 'histone code' in many cases,extend the information potential of the genetic code by regulating DNA at the epigenetic level.Many PTMs occur on non-histone proteins as well as histones,regulating protein-protein interactions,stability,localization,and/or enzymatic activities of proteins involved in diverse cellular processes.Although protein phosphorylation,ubiquitylation,and acetylation have been extensively studied,only a few proteins other than histones have been reported that can be modified by lysine methylation.This review summarizes the current progress on lysine methylation of nonhistone proteins,and we propose that lysine methylation,like phosphorylation and acetylation,is a common PTM that regulates proteins in diverse cellular processes.

  20. Preparation of diethylene glycol monomethyl ether monolaurate catalyzed by active carbon supported KF/CaO.

    Science.gov (United States)

    Lou, Shengfeng; Jia, Lihua; Guo, Xiangfeng; Wu, Ping; Gao, Lianbing; Wang, Jianjun

    2015-01-01

    Diethylene glycol monomethyl ether monolaurate (DGMEML) was synthesized via the reaction of diethylene glycol monomethyl ether (DGME) with methyl laurate (ML) by a new solid base catalyst of KF/CaO/AC, which was prepared by impregnation method using active carbon as carrier. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen physisorption-desorption and Hammett indicator methods; the effect of the mole ratio of KF to CaO, DGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of DGMEML were studied; and the relationship between the structure of the catalyst and the yield of DGMEML was investigated. The formed KCaF3 and K2O were acting as the main active components in the catalytic transesterification; the highest yield of 96.3 % was obtained as KF-to-CaO molar ratio of 2.0, DGME to ML molar ratio of 4.0, catalyst amount of 5 wt%, and reaction time of 30 min at 75 °C; and the catalyst displayed good stability in the transesterification.

  1. Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    Science.gov (United States)

    Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

    2011-02-01

    In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from

  2. Synthesis and Characterization of a Gasoline Oxygenate, Ethyl tert-Butyl Ether

    Science.gov (United States)

    Donahue, Craig J.; D'Amico, Teresa; Exline, Jennifer A.

    2002-06-01

    A laboratory procedure involving the synthesis and characterization of ethyl tert-butyl ether (ETBE) is described. This experiment has been used in a general chemistry sequence that includes a section on organic chemistry, but is also well suited for an introductory organic chemistry laboratory course. ETBE is prepared by the acid-catalyzed reaction of tert-butyl alcohol with ethyl alcohol. The product is recovered as a low-boiling azeotrope and purified by liquid liquid extraction with water. By using gas chromatography and IR spectroscopy to examine both the crude and the purified products, students can see how much the purity of their sample improves. They can also appreciate the value of these methods (especially GC) as tools to establish purity. Student results are presented. The use of ETBE and its more prominent cousin methyl tert-butyl ether (MTBE) as gasoline oxygenates has become very controversial because they have polluted underground water supplies. This lab permits students to prepare a compound that has a real use and regularly makes headlines in the news. This lab experiment is part of an effort to develop a general chemistry sequence for engineering students using the theme of "Chemistry and the Automobile".

  3. Effective utilization of B20 blend with diethyl ether and ethanol as oxygenated additives

    Directory of Open Access Journals (Sweden)

    Upadrasta-Satya Vara-Prasad

    2011-01-01

    Full Text Available In the recent times' fatty acid methyl ester popularly called as biodiesel has become more prominent alternate fuel for compression ignition engines based on a single fuel concept. Since, use of neat biodiesel on a large scale is raising certain difficulties and is being adopted in a blended form with petro-diesel fuel and B20 blend has become standardized. However, the HC and NOx emissions of B20 are still on the higher side. Present work aims at experimental evaluation of a single cylinder water-cooled diesel engine by adopting various proportions of ethanol and diethyl ether blends in order to improve performance and emission characteristics of B20 blend. Besides employing different amounts of ethanol and diethyl ether, simultaneous influence of injector nozzle hole size and fuel injection pressure are also investigated to arrive at an optimum configuration. Brake specific fuel consumption and hydrocarbon emissions values are lower with B20 and DEE 5 whereas B20 with DEE15 yielded lower NOx emissions. It is observed that addition of oxygenates have improved the combustion process and lower emissions are obtained. The present investigation revealed that blends with oxygenated additives having higher Cetane rating are superior to neat blend.

  4. Synthesis of novel poly(aryl ether amide)s containing the phthalazinone moiety

    Institute of Scientific and Technical Information of China (English)

    CHENG, Lin(程琳); JIAN, Xi- Gao(蹇锡高)

    2000-01-01

    Two novel heterocyclic diamine monomers: 1,2-dihydro-2-(4-aminophenyl)-4- [ 4-( 4-aminophenoxy ) phenyl ]-( 2H )-phtha-lazin-1-one and 1, 2-dihydro-2-( 4-aminophenyl)-4-[ 4-( 4-aminophenoxy)-3, 5-dimethylphenyl]-(2H)-phthalazin-1-one were successfully synthesized using readily available heterocyclic bisphenol-like monomers through two steps in high yield. A series of novel poly(aryl ether amide)s containing the phthalazinone moiety with inherent viscosities of 1.16-1.67 dL/g were prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. The polymers were readily soluble in a variety of solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc),dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidinone (NMP), and pyridine. The polymers had high glass transition tenperatured(Tg) in the 291-329℃ range.

  5. Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

    Science.gov (United States)

    Jimenez, Leonel R.; Tolentino, Daniel R.; Gallon, Benjamin J.; Schrodi, Yann

    2012-01-01

    The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh3)3 and RuCl2(pcymene)(L), where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-npropylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes. PMID:22580400

  6. Immediate and delayed allergy from epoxy resins based on diglycidyl ether of bisphenol A.

    Science.gov (United States)

    Kanerva, L; Jolanki, R; Tupasela, O; Halmepuro, L; Keskinen, H; Estlander, T; Sysilampi, M L

    1991-06-01

    This case report presents two patients with immediate and delayed allergy to epoxy resins based on diglycidyl ether of bisphenol A (DGEBA). In patch testing, the epoxy resin (DGEBA-based) of the standard series gave allergic reactions. Both patients had a prick test reaction of histamine size or larger to the human serum albumin (HSA) conjugate of DGEBA-based epoxy resins. One had been occupationally exposed to methyl tetrahydrophthalic anhydride (MTHPA) and had a histamine-size prick test reaction to the HSA conjugate of MTHPA; the other did not react to the conjugate. Determinations of specific immunoglobulin E were carried out with HSA-DGEBA conjugates, two DGEBA-based epoxy resins, and phthalic anhydrides. The first patient had positive tests to DGEBA, the DGEBA-based epoxy resins, and two phthalic anhydrides, and the second to DGEBA and the DGEBA-based epoxy resins, but not to the phthalic anhydrides.

  7. Steam Reforming of Dimethyl Ether by Gliding Arc Gas Discharge Plasma for Hydrogen Production

    Institute of Scientific and Technical Information of China (English)

    王保伟; 孙启梅; 吕一军; 杨美琳; 闫文娟

    2014-01-01

    Gliding arc gas discharge plasma was used for the generation of hydrogen from steam reforming of di-methyl ether (DME). A systemic procedure was employed to determine the suitable experimental conditions. It was found that DME conversion first increased up to the maximum and then decreased slightly with the increase of added water and air. The increase of total feed gas flow rate resulted in the decrease of DME conversion and hy-drogen yield, but hydrogen energy consumption dropped down to the lowest as total feed gas flow rate increased to 76 ml·min-1. Larger electrode gap and higher discharge voltage were advantageous. Electrode shape had an impor-tant effect on the conversion of DME and production of H2. Among the five electrodes, electrode 2# with valid length of 55 mm and the radian of 34 degrees of the top electrode section was the best option, which enhanced ob-viously the conversion of DME.

  8. 17O NMR parameters of some substituted benzyl ethers components: Ab initio study

    Directory of Open Access Journals (Sweden)

    Mahdi Rezaei Sameti

    2016-09-01

    Full Text Available The 17O NMR chemical shielding tensors and chemical shift for a set of substituted benzyl ethers derivatives containing (methyl, ethyl, isopropyl, t-butyl, brome and lithium have been calculated. The molecular structures were fully optimized using B3LYP/6-31G(d,p. The calculation of the 17O shielding tensors employed the GAUSSIAN 98 implementation of the gauge-including atomic orbital (GIAO and continuous set of gauge transformations (CSGT by using 6-31G (d,p, 6-31++G(d,p and 6-311++G(d,p basis set methods at density functional levels of theories (DFT. The values determined using the GIAO and CSGT were found to give a good agreement with the experimental chemical shielding.

  9. Determination of optimal conditions for obtaining 1,3-dimethoxy-1-phenyl-propane by addition of methylal to styrene

    Energy Technology Data Exchange (ETDEWEB)

    Brudnik, I.M.; Akhmatdinov, R.T.; Kantor, E.A.; Rakhmankulov, D.L.

    1988-02-10

    The reaction of styrene with methylal was investigated in order to reveal the regularities of the reaction and determine the conditions for obtaining acceptable yields of 1,3-dimethoxy-1-phenylpropane. Earlier, boron trifluoride was recommended as catalyst of the reaction. However, the necessity of working at low temperatures or under pressure makes this catalyst inconvenient for quantitative syntheses. The primary task of the investigation was determination of the possibility of using some other acidic catalysts, particularly sulfuric acid, para toluenesulfonic acid monohydrate, KU-2 cation-exchanger, zinc chloride, and boron trifluoride etherate. The most effective and selective of the investigated catalysts is boron trifluoride etherate.

  10. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  11. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Science.gov (United States)

    Mai, Zhensheng; Zhang, Huamin; Li, Xianfeng; Bi, Cheng; Dai, Hua

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test.

  12. Evaluation of Stabilization Performances of Antioxidants in Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zheng; ZHOU Fu-gui; ZHANG Shu-ling; MU Jian-xin; YUE Xi-gui; WANG Gui-bin

    2012-01-01

    Two types of antioxidants(a primary antioxidant and a secondary antioxidant) were used to improve the stability of poly(ether ether ketone)(PEEK).The effects of the antioxidants on the properties of PEEK and the stabilization mechanism were investigated by some characterization methods,such as rheometer,thermogravinetric analysis(TGA),universal tester and electron spin resonance(ESR).The results indicate that the efficiency of the phosphorous antioxidant(DS) in improving the stability of PEEK was better than that of the phenolic antioxidant(DN) in both melting stability and thermal stability,and the thermal stability of PEEK sample containing 0.07%(mass fraction) DS was the best among all the samples due to the decrease of the free radicals density,as proven by ESR measurement.Additionally,no obvious changes could be observed in mechanical properties of PEEK containing antioxidants compared to those of virgin PEEK.

  13. ELECTROCHEMICAL POLYMERIZATION OF 5-CYANOINDOLE IN MIXED ELECTROLYTES OF BORON TRIFLUORIDE DIETHYL ETHERATE AND DIETHYL ETHER

    Institute of Scientific and Technical Information of China (English)

    Jing-kun Xu; Wei-qiang Zhou; Jian Hou; Shou-zhi Pu; Jing-wu Wang; Liu-shui Yan

    2006-01-01

    High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0.05 mol L-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films. The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10-2 Scm-1. Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-light emitter.

  14. Polymeric 32-channel arrayed waveguide grating multiplexer using fluorinated poly (ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    Fei Wang(王菲); Wei Sun(孙伟); Aize Li(李艾泽); Maobin Yi(衣茂斌); Zhenhua Jiang(姜振华); Daming Zhang(张大明)

    2004-01-01

    In wavelength division multiplexing (WDM) systems, an arrayed waveguide grating (AWG) multiplexer is a key component. A polymeric AWG multiplexer has recently attracted much attention due to its low cost processing and a potential of integration with other devices. Fluorinated poly (ether ether ketone)(FPEEK) is excellent material for fabrication of optical waveguides due to its low absorption loss at 1.55-μm wavelength and high thermal stability. A 32-channel AWG multiplexer has been designed based on the grating diffraction theory and fabricated using newly synthesized FPEEK. During the fabrication process of the Polymer/Si AWG device, spin coating, vaporizing, photolithographic patterning and reactive ion etching (RIE) are used. The AWG multiplexer measurement system is based on a tunable semiconductor laser, infrared camera and a Peltier-type heater. The device exhibits a wavelength channel spacing of 0.8nm and a center wavelength of 1548 nm in the room temperature.

  15. Modification of Poly(ether ether ketone Polymer for Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Devesh Shukla

    2013-01-01

    Full Text Available Polyelectrolyte membrane (PEM is an important part of PEM fuel cell. Nafion is a commercially known membrane which gives the satisfactory result in PEM fuel cell operating at low temperature. Present research paper includes functionalization of Poly(ether ether ketone (PEEK polymer with phosphonic acid group. The functionalization was done with the help of nickel-based catalyst. Further, the polymer was characterized by the FTIR, EDAX, DSC, TGA, and 1H NMR, and it was found that PEEK polymer was functionalized with phosphonic acid group with good thermal stability in comparison to virgin PEEK. Finally, the thin films of functionalized polymer were prepared by solution casting method, and proton conductivity of film samples was measured by impedance spectra whose value was found satisfactory with good thermal stability in comparison to commercially available Nafion membrane.

  16. Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

    Energy Technology Data Exchange (ETDEWEB)

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang, E-mail: wolfgang.bacsa@cemes.fr [CEMES-CNRS and University of Toulouse, 29 Jeanne Marvig, 31055 Toulouse (France); Boyer, François; Olivier, Philippe [Université de Toulouse, Institut Clément Ader, I.U.T. Université Paul Sabatier - 133C Avenue de Rangueil - B.P. 67701, 31077 Toulouse CEDEX 4 (France); Sapelkin, Andrei [School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, E1 4NS London (United Kingdom); King, Stephen; Heenan, Richard [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri [AIRBUS FRANCE (B.E. M and P Toulouse), 316 Route de Bayonne, 31060 Toulouse (France)

    2014-06-21

    Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

  17. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

    2011-01-01

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

  18. Dielectric properties of poly (1,4-phenylene ether-ether-sulfone)

    CERN Document Server

    Spasevska, H

    2002-01-01

    Dielectric properties of Poly (1,4-phenylene ether-ether-sulfone) are obtained from dielectric spectroscopy of the polymer pellet. The values of relative dielectric constant epsilon', dielectric losses epsilon sup , dielectric dissipation factor tan delta and complex impedance are obtained at temperature of 75 sup o C. The temperature dependence of these parameters is investigated for three frequencies (8x10 sup 4 Hz; 8x10 sup 5 Hz; 8x10 sup 6 Hz) of applied electric field. The specific conductivity sigma, which depends on temperature, is related to the ohmic resistance R, at temperature in the interval from 66 to 83 sup o C. Fitting the experimental data, the value of the activation energy U is obtained. (Original)

  19. A Facile and Efficient Synthesis of Diaryl Amines or Ethers under Microwave Irradiation at Presence of KF/Al2O3 without Solvent and Their Anti-Fungal Biological Activities against Six Phytopathogens

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2013-09-01

    Full Text Available A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae.

  20. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Ruffmann, B.; Vetter, S.; Nunes, S.P. [GKSS Research Centre, Max-Planck Str., 21502 Geesthacht (Germany)

    2006-05-05

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion{sup (R)} 112 was used as reference material. DMFC tests were also performed at 50{sup o}C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion{sup (R)} 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD=71% showed to have similar performance, or even better, as that of Nafion{sup (R)} 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD=52%. (author)

  1. Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

    2014-02-15

    Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

  2. Mol-ecular and crystal structure of gossypol tetra-methyl ether with an unknown solvate.

    Science.gov (United States)

    Honkeldieva, Muhabbat; Talipov, Samat; Mardanov, Rustam; Ibragimov, Bakhtiyar

    2015-02-01

    The title compound, C34H38O8 (systematic name: 5,5'-diisopropyl-2,2',3,3'-tetra-meth-oxy-7,7'-dimethyl-2H,2'H-8,8'-bi-[naphtho-[1,8-bc]furan]-4,4'-diol), has been obtained from a gossypol solution in a mixture of dimethyl sulfate and methanol. The mol-ecule is situated on a twofold rotation axis, so the asymmetric unit contains one half-mol-ecule. In the mol-ecule, the hy-droxy groups are involved in intra-molecular O-H⋯O hydrogen bonds, and the two naphthyl fragments are inclined each to other by 83.8 (1)°. In the crystal, weak C-H⋯O and C-H⋯π inter-actions consolidate the packing, which exhibits channels with an approximate diameter of 6 Å extending along the c-axis direction. These channels are filled with highly disordered solvent mol-ecules, so their estimated scattering contribution was subtracted from the observed diffraction data using the SQUEEZE option in PLATON [Spek, A. L. (2015). Acta Cryst. C71, 9-18].

  3. TRANSPORT OF METHYL TERT-BUTYL ETHER THROUGH ALFALFA PLANTS. (R825549C062)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  4. REMOVAL OF METHYL TERTIARY BUTYL ETHER (MTBE) FROM GROUNDWATER USING PHOTOCATALYSIS

    Science.gov (United States)

    The potential of photocatalysis was determined for treating MTBE-contaminated drinking water supplies. Two liquid-phase systems, a falling film reactor, and a solar degradation system, are being evaluated. We are also conducting a gas-phase treatment method to simulate an integra...

  5. 75 FR 4288 - Oxirane, 2-Methyl-, Polymer with Oxirane, Dimethyl Ether; Tolerance Exemption

    Science.gov (United States)

    2010-01-27

    ... natural aquatic environment. 2. The polymer does contain as an integral part of its composition the atomic... composition, except as impurities, any element other than those listed in 40 CFR 723.250(d)(2)(ii). 4. The... recordkeeping requirements. Dated: January 19, 2010. Lois Rossi, Director, Registration Division, Office...

  6. Modeling Of A Reactive Distillation Column: Methyl Tertiary Butyl Ether (Mtbe Simulation Studies

    Directory of Open Access Journals (Sweden)

    Ismail Mohd Saaid Abdul Rahman Mohamed and Subhash Bhatia

    2012-10-01

    Full Text Available A process simulation stage-wise reactive distillation column model formulated from equilibrium stage theory was developed. The algorithm for solving mathematical model represented by sets of differential-algebraic equations was based on relaxation method. Numerical integration scheme based on backward differentiation formula was selected for solving the stiffness of differential-algebraic equations. Simulations were performed on a personal computer (PC Pentium processor through a developed computer program using FORTRAN90 programming language. The proposed model was validated by comparing the simulated results with the published simulation results and with the pilot plant data from the literature. The model was capable of predicting high isobutene conversion for heterogeneous system, as desirable in industrial MTBE production process. The comparisons on temperature profiles, liquid composition profile and operating conditions of reactive distillation column also showed promising results. Therefore the proposed model can be used as a tool for the development and simulation of reactive distillation column.Keywords: Modeling, simulation, reactive distillation, relaxation method, equilibrium stage, heterogeneous, MTBE

  7. Molecular dynamics model of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Lin, B.; Halley, W.J. [Univ. of Minnesota, Minneapolis, MN (United States)

    1995-11-02

    We report a molecular dynamics model of the monomeric liquid dimethyl ether. The united atom approach is used to treat CH{sub 3} groups as point source centers. Partial charges are derived from the experimental dipole moment. Harmonic force constants are used for intramolecular interactions, and their values are so chosen that the model`s fundamental frequencies agree with experimental results. Because we are interested in solvation properties, the model contains flexible molecules, allowing molecular distortion and internal dynamical quantities. We report radial distribution functions and the static structure factors as well as some dynamical quantities such as the dynamical structure factor, infrared absorption, and Raman scattering spectra. Calculated results agree reasonably well with experimental and other simulation results. 25 refs., 8 figs., 1 tab.

  8. Thermolysis of phenethyl phenyl ether: A model of ether linkages in low rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Britt, P.F.; Buchanan, A.C. III; Malcolm, E.A.

    1994-09-01

    Currently, an area of interest and frustration for coal chemists has been the direct liquefaction of low rank coal. Although low rank coals are more reactive than bituminous coals, they are more difficult to liquefy and offer lower liquefaction yields under conditions optimized for bituminous coals. Solomon, Serio, and co-workers have shown that: in the pyrolysis and liquefaction of low rank coals, a low temperature cross-linking reaction associated with oxygen functional groups occurs before tar evolution. A variety of pretreatments (demineralization, alkylation, and ion-exchange) have been shown to reduce these retrogressive reactions and increase tar yields, but the actual chemical reactions responsible for these processes have not been defined. In order to gain insight into the thermochemical reactions leading to cross-linking in low rank coal, we have undertaken a study of the pyrolysis of oxygen containing coal model compounds. Solid state NMR studies suggest that the alkyl aryl ether linkage may be present in modest amounts in low rank coal. Therefore, in this paper, we will investigate the thermolysis of phenethyl phenyl ether (PPE) as a model of 0-aryl ether linkages found in low rank coal, lignites, and lignin, an evolutionary precursor of coal. Our results have uncovered a new reaction channel that can account for 25% of the products formed. The impact of reaction conditions, including restricted mass transport, on this new reaction pathway and the role of oxygen functional groups in cross-linking reactions will be investigated.

  9. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Sik [Los Alamos National Laboratory; Kim, Yu Seung [Los Alamos National Laboratory; Lee, Kwan - Soo [Los Alamos National Laboratory; Boncella, James M [Los Alamos National Laboratory; Kuiper, David [Los Alamos National Laboratory; Guiver, Michael D [CANADA

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  10. Ruthenium(II) alpha-Diimine Complexes with One, Two, and Three 4,4'-Bis(hydroxymethyl)-2,2'-bipyridine and 4,4'-Bis(chloromethyl)-2,2'-bipyridine Ligands: Useful Starting Materials for Further Derivatization.

    Science.gov (United States)

    Collins, James E.; Lamba, Jaydeep J. S.; Love, J. Christopher; McAlvin, John E.; Ng, Christina; Peters, Benjamin P.; Wu, Xufeng; Fraser, Cassandra L.

    1999-05-03

    Although Ru(II) tris(bipyridine) complexes and related alpha-diimine analogues find wide use in chemistry, many common ligand and metal complex derivatives are difficult to synthesize. The halomethyl bpy ligands and their inert metal complexes are one such example. These compounds are desirable since they serve as useful starting materials for a variety of more elaborate derivatives. Although 4,4'-bis(halomethyl)-2,2'-bipyridine ligands readily chelate to labile metal ions, they are not compatible with the higher temperatures and polar solvents typically required to effect ligand substitution at more inert Ru centers. Alternate routes to these targets involving solvento and other substitution labile intermediates yield products, but yields are typically low due to difficulties in purification. This report describes a new route to Ru(II) halomethyl bpy complexes involving chelation of the more robust 4,4'-bis(hydroxymethyl)-2,2'-bipyridine, bpy(CH(2)OH)(2), followed by conversion to the corresponding chloromethyl species on the metal using oxalyl chloride and DMF in THF or CH(3)CN solution. This new "OH to Cl" methodology is demonstrated for Ru(II) complexes with two, four, and six functionalities with both bpy and phen ancillary ligands. Complexes of the general formula [L(n)()Ru{bpy(CH(2)X)(2)}(3)(-)(n)()](PF(6))(2) (L = bpy, phen; X = OH, Cl; n = 0-2) have been prepared in good yield and are conveniently purified by precipitation. These Ru alpha-diimine complexes have already been utilized as multifunctional metalloinitiators for controlled cationic and radical polymerizations. They promise to be valuable for bpy derivatization generally.

  11. In vitro glucuronidation of the primary metabolite of 10-chloromethyl-11-demethyl-12-oxo-calanolide A by human liver microsomes and its interactions with UDP-glucuronosyltransferase substrates.

    Science.gov (United States)

    Liu, Xin; Sheng, Li; Zhao, Manman; Mi, Jiaqi; Liu, Zhihao; Li, Yan

    2015-02-01

    F18 (10-chloromethyl-11-demethyl-12-oxo-calanolide), an analog of (+)-Calanolide A, is a novel small-molecule nonnucleoside reverse transcriptase inhibitor for the therapy of human immunodeficiency virus (HIV) infection. M3, the most abundant primary metabolite of F18 in human liver microsomes (HLMs) and rat liver microsomes (RLMs), is mainly excreted in bile as a glucuronide conjugate in rats after oral administration. The aim of this study was to identify the UDP glucuronosyltransferase (UGT) isoforms involved in the glucuronidation of M3 by HLMs and recombinant human UGTs and investigate the metabolic interactions of M3 with the substrates of UGTs in HLMs. As a result, UGT1A1 was the major isozyme responsible for the glucuronidation of M3, followed by UGT1A4, UGT1A9 and UGT2B7. M3 exhibited significant inhibition against UGT1A9 and UGT2B7 in both HLMs and recombinant human UGTs. In addition, M3 inhibited UGT1A9 catalyzed mycophenolic acid (MPA) glucuronidation with Ki of 0.39 μM, and M3 also inhibited the glucuronidation of 3'-azido-3'-deoxythymidine (AZT) by a "mixed-type" mechanism with Ki of 16.8 μM. The results suggest that UGT1A1 provides the major contribution to M3 glucuronidation in vitro and M3 has the potential to interact with xenobiotics and endogenous chemicals that are UGT1A9 and UGT 2B7 substrates.

  12. Structural investigation of aryllithium clusters in solution. I. A 13C and 7Li NMR studyof phenyllithium and some methyl-substituted phenyllithium derivatives

    NARCIS (Netherlands)

    Koten, G. van; Wehman, E.; Jastrzebski, J.T.B.H.; Ernsting, J.M.; Grove, D.M.

    1988-01-01

    }1{}3{C and }7{Li NMR spectra of phenyllithium and several methyl subsituted phenyllithium derivatives have been recorded in the presence of known amounts of coordinating solvents such as monodentate diethyl ether and THF and the potentially bidentate TMEDA (tetramethylethylenediamine). The relative

  13. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

    2016-06-01

    Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

  14. 德国赫优讯EtherCAT新产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    EtherCAT作为实时以太网协议之一,以其强大的性能和“On the fly”的速度,以及网络抖动小于1μs的同步功能.成为发展最快的实时网络协议。同时,EtherCAT全球组织在中国代表处的设立,表明了EtherCAT全球组织对中国市场的关心。

  15. Impact of cellulose ethers on the cement paste microstructure

    OpenAIRE

    Pourchez, Jérémie; Grosseau, Philippe; Rouèche-Pourchez, Emilie; Debayle, Johan; Pinoli, Jean-Charles; Maire, Eric; Boller, Elodie; Parra-Denis, Estelle

    2007-01-01

    ISBN = 3-87264-022-4 7 pages; International audience; Complementary investigation tools (2D and 3D observations by optical microscopy and fast X-ray microtomography and then image analysis) were developed in order to examine the effects of cellulose ethers on the cement paste microstructure. The obtained results show that the presence of cellulose ether may induce an increase of both 50-250 µm-diameter air voids. The chemistry of the cellulose ethers appears as a main controlling factor of th...

  16. Synthesis and Adsorption Property of Dihydroxyl Azacrown Ether-Grafted Chitosan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.

  17. - Tunneling Matrix Formalism for - and Two-Methyl Molecules Based on the Extended Permutation-Inversion Group Idea and its Application to the Analyses of the Methyl-Torsional Rotational Spectra

    Science.gov (United States)

    Ohashi, Nobukimi; Kobayashi, Kaori; Fujitake, Masaharu

    2016-06-01

    Recently we reanalyzed the microwave absorption spectra of the trans-ethyl methyl ether molecule, state by state, in the ground vibrational, O-methyl torsional, C-methyl torsional and skeletal torsional states with the use of an IAM-like tunneling matrix formalism based on an extended permutation-inversion (PI) group idea, whose results appeared in Journal of Molecular Spectroscopy recently. Since a single rho-axis does not exist in trans-ethyl methyl ether that has two methyl-tops and the IAM formalism is not available as in the case of the one methyl-top molecule, we adopted instead an IAM-like (in other word, partial IAM) formalism. We will show the outline of the present formalism and the results of the spectral analyses briefly. We also would like to review the IAM formalism for the one top molecules based on the extended PI group, and show the result of the application to the spectral analysis. If possible, we would like to compare the IAM and IAM-like formalisms based on the extended PI group with the ERHAM formalism developed by Groner, especially, in the form of Hamiltonian matrix elements, and discuss about similarity and difference.

  18. Kinetic studies on the etherification of C5-alkenes to fuel ether tame

    Energy Technology Data Exchange (ETDEWEB)

    Paeaekkoenen, P.

    2003-07-01

    Tertiary ethers are formed in reactions between alcohols and alkenes and are used in reformulated gasoline as octane-enhancing agents. By blending ethers into the gasoline pool, less ground-level ozone is formed and combustion of the gasoline is more efficient as a result of the oxygen boost. The main goal of this research was to study the synthesis of TAME (tert-amyl methyl ether, 2-methoxy-2-methylbutane) and to formulate a kinetic model as precise as possible for process design purposes. The reaction rate was studied as a function of temperature and the reagents feed molar ratio with conventional ion-exchange resin beads and a novel fibrous ion-exchange catalyst. Kinetic modelling favoured the Langmuir-Hinshelwood type model, derived from a dual-site mechanism for the etherification. The influence of the acid capacity of the catalysts on the reaction rate was found to be second order. These results suggest that the etherification reactions occur via a dual-site mechanism. Comparison of the values of the kinetic parameters obtained with a fibre catalyst and with a bead catalyst indicated that diffusion limitations are associated with the latter. Therefore, mass transfer of the reacting components inside the pores of the cationic ion- exchange resin bead was estimated in terms of the effectiveness factors calculated from experiments with different resin bead sizes. It was concluded that mass transfer has to be taken into account when applying the kinetic model, which was derived for resin beads as the catalyst. High temperatures and high alcohol concentrations favoured the formation of the dialkyl ethers (dehydration) as a side reaction. When the reaction was maintained in a kinetic regime, it was highly selective for tert-etherification, since the rate of tert-etherification was 140 to 270 times that of dehydration. The experimental results were best described with a model in which one alcohol molecule is adsorbed and the other reacts from the liquid phase. The

  19. Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Nordiana; Ali, Ab Malik Marwan [Ionic Material and Devices Research Laboratory, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Lepit, Ajis; Rasmidi, Rosfayanti [Faculty of Applied Sciences, Universiti Teknologi MARA Sabah, Beg Berkunci 71, 88997 Kota Kinabalu (Malaysia); Subban, Ri Hanum Yahaya [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Science & Technology, Universiti Pertahanan Nasional Malaysia, 57000 Kuala Lumpur (Malaysia)

    2015-08-28

    Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d{sub 6}) solution of the purified polymer using {sup 1}H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10{sup −3} Scm{sup −1} at 30°C and 3.383 × 10{sup −3} Scm{sup −1} at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

  20. Thermodynamic equilibrium calculations of hydrogen production from the combined processes of dimethyl ether steam reforming and partial oxidation

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.

    Thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the combined processes of dimethyl ether (DME) partial oxidation and steam reforming were investigated as a function of oxygen-to-carbon ratio (0.00-2.80), steam-to-carbon ratio (0.00-4.00), temperature (100 °C-600 °C), pressure (1-5 atm) and product species. Thermodynamically, dimethyl ether processed with air and steam generates hydrogen-rich fuel-cell feeds; however, the hydrogen concentration is less than that for pure DME steam reforming. Results of the thermodynamic processing of dimethyl ether indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 °C, oxygen-to-carbon ratios greater than 0.00 and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure has negligible effects on the hydrogen content. Thermodynamically, dimethyl ether can produce concentrations of hydrogen and carbon monoxide of 52% and 2.2%, respectively, at a temperature of 300 °C, and oxygen-to-carbon ratio of 0.40, a pressure of 1 atm and a steam-to-carbon ratio of 1.50. The order of thermodynamically stable products (excluding H 2, CO, CO 2, DME, NH 3 and H 2O) in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol and methyl-ethyl ether; trace amounts of formaldehyde, formic acid and methanol are observed. Ammonia and hydrogen cyanide are also thermodynamically favored products. Ammonia is favored at low temperatures in the range of oxygen-to-carbon ratios of 0.40-2.50 regardless of the steam-to-carbon ratio employed. The maximum ammonia content (i.e., 40%) occurs at an oxygen-to-carbon ratio of 0.40, a steam-to-carbon ratio of 1.00 and a temperature of 100 °C. Hydrogen cyanide is favored at high temperatures and low oxygen-to-carbon ratios with a maximum of 3.18% occurring at an oxygen-to-carbon ratio of 0.40 and a steam

  1. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  2. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  3. Evaluation of crystallization kinetics of poly (ether-ketone-ketone and poly (ether-ether-ketone by DSC

    Directory of Open Access Journals (Sweden)

    Gibran da Cunha Vasconcelos

    2010-08-01

    Full Text Available The poly (aryl ether ketones are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the developed structure, and the properties of the final product. The objective of this work was to evaluate the thermoplastics polymers PEKK e PEEK by DSC, aiming to obtain the relationship between kinetics, content, nucleation and geometry of the crystalline phases, according to the parameters of the Avrami and Kissinger models. The analysis of the Avrami exponents obtained for the studied polymers indicates that both showed the formation of crystalline phases with heterogeneous nucleation and growth geometry of the type sticks or discs, depending on the cooling conditions. It was also found that the PEEK has a higher crystallinity than PEKK.

  4. Ecofriendly and Simplified Synthetic Route for Polysulfone-based Solid-State Alkaline Electrolyte Membrane

    Directory of Open Access Journals (Sweden)

    Nittaya Pantamas

    2012-01-01

    Full Text Available Problem statement: Recently the alkaline system for fuel cell enhance their presence because of possibility of no-precious-metal catalyst and low over potential at cathode reaction. The anion exchange membrane for alkaline membrane fuel cell should be a key technology in order to achieve the practical performance as fuel cells. Alkaline anion exchange membranes of high ionic conductivities are made from polysulfone by adding a chloromethyl pendant group to the polysulfone, follow by reacting the chloromethyl group with amine to form quarternary ammonium pendant groups which act as the counter ion for hydroxide anion. Chloromethyl methyl ether, N,N-dimethylformamide and methanol are commonly used as agent for providing excellent conversions, but they are now considered to be carcinogenic. To avoid the use of such hazardous materials, in our work we used paraformaldehyde, chlorotrimethylsilane, N-methylpyrrolidone and ethanol as agent for providing conversion. Approach: Polysulfone (PS was chloromethylated using chlorotrimethylsilane as a chloromethylation reagent, resulting in the formation of Chloromethylated Polysulfone (CMPS. CMPS was converted to a quaternized form using trimethylamine and precipitated into ethanol. The powder was dissolved in N-methylpyrrolidone, followed by aminated with a 25 wt% trimethylamine. Results: The resulting solution was cast onto a flat glass plate and dried in an oven. The membrane was immersed in KOH solution for 24 h to replace the Cl- anion in the polymer with OH-. Conclusion: The swelling behavior of polysulfone-based solid-state alkaline electrolyte membrane was closely related to the degree of water uptake (25 WU%, 7.5 SD% and the ion-exchange capacity was 1.05 mmol g-1, which is sufficient for electrolyte membranes used in alkaline fuel cells.

  5. Ethyl tertiary-butyl ether: a toxicological review.

    Science.gov (United States)

    McGregor, Douglas

    2007-05-01

    A number of oxygenated compounds (oxygenates) are available for use in gasoline to reduce vehicle exhaust emissions, reduce the aromatic compound content, and avoid the use of organo-lead compounds, while maintaining high octane numbers. Ethyl tertiary-butyl ether (ETBE) is one such compound. The current use of ETBE in gasoline or petrol is modest but increasing, with consequently similar trends in the potential for human exposure. Inhalation is the most likely mode of exposure, with about 30% of inhaled ETBE being retained by the lungs and distributed around the body. Following cessation of exposure, the blood concentration of ETBE falls rapidly, largely as a result of its metabolism to tertiary-butyl alcohol (TBA) and acetaldehyde. TBA may be further metabolized, first to 2-methyl-1,2-propanediol and then to 2-hydroxyisobutyrate, the two dominant metabolites found in urine of volunteers and rats. The rapid oxidation of acetaldehyde suggests that its blood concentration is unlikely to rise above normal as a result of human exposure to sources of ETBE. Single-dose toxicity tests show that ETBE has low toxicity and is essentially nonirritant to eyes and skin; it did not cause sensitization in a maximization test in guinea pigs. Neurological effects have been observed only at very high exposure concentrations. There is evidence for an effect of ETBE on the kidney of rats. Increases in kidney weight were seen in both sexes, but protein droplet accumulation (with alpha(2u)-globulin involvement) and sustained increases in cell proliferation occurred only in males. In liver, centrilobular necrosis was induced in mice, but not rats, after exposure by inhalation, although this lesion was reported in some rats exposed to very high oral doses of ETBE. The proportion of liver cells engaged in S-phase DNA synthesis was increased in mice of both sexes exposed by inhalation. ETBE has no specific effects on reproduction, development, or genetic material. Carcinogenicity studies

  6. Apoptosis and DNA Methylation

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Huan X.; Hackett, James A. [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Nestor, Colm [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Dunican, Donncha S.; Madej, Monika; Reddington, James P. [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Pennings, Sari [Queen' s Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Harrison, David J. [Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Meehan, Richard R., E-mail: Richard.Meehan@hgu.mrc.ac.uk [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom)

    2011-04-01

    Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG.

  7. Apoptosis and DNA Methylation

    Directory of Open Access Journals (Sweden)

    Richard R. Meehan

    2011-04-01

    Full Text Available Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG.

  8. 德国赫优讯EtherCAT产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    德国赫优讯自动化系统有限公司作为EtherCAT国际组织的重要成员之一,推出基于实时以太网EtherCAT的计算机通信板卡cifX系列产品和嵌入式通信模块comX系列产品。

  9. Effect of diethyl ether on the biliary excretion of acetaminophen.

    Science.gov (United States)

    Watkins, J B; Siegers, C P; Klaassen, C D

    1984-10-01

    The biliary and renal excretion of acetaminophen and its metabolites over 8 hr was determined in rats exposed to diethyl ether by inhalation for 1 hr. Additional rats were anesthetized with urethane (1 g/kg ip) while control animals were conscious throughout the experiment (surgery was performed under hexobarbital narcosis: 150 mg/kg ip; 30-min duration). The concentration of UDP-glucuronic acid was decreased 80% in livers from ether-anesthetized rats but was not reduced in urethane-treated animals when compared to that in control rats. The concentration of reduced glutathione was not affected by either urethane or diethyl ether. Basal bile flow was not altered by the anesthetic agents. Bile flow rate after acetaminophen injection (100 mg/kg iv) was increased slightly over basal levels for 2 hr in hexobarbital-treated control rats, was unaltered in urethane-anesthetized animals, and was decreased throughout the 8-hr experiment in rats exposed to diethyl ether for 1 hr. In control and urethane-anesthetized animals, approximately 30-35% of the total acetaminophen dose (100 mg/kg iv) was excreted into bile in 8 hr, while only 16% was excreted in rats anesthetized with diethyl ether. Urinary elimination (60-70% of the dose) was not altered by exposure to ether. Separation of metabolites by reverse-phase high-pressure liquid chromatography showed that ether decreased the biliary elimination of unchanged acetaminophen and its glucuronide, sulfate, and glutathione conjugates by 47, 40, 49, and 73%, respectively, as compared to control rats. Excretion of unchanged acetaminophen and the glutathione conjugate into bile was depressed in urethane-anesthetized animals by 45 and 66%, respectively, whereas elimination of the glucuronide and sulfate conjugates was increased by 27 and 50%, respectively. These results indicate that biliary excretion is influenced by the anesthetic agent and that diethyl ether depresses conjugation with sulfate and glutathione as well as glucuronic

  10. Marine Sponge Dysidea herbacea revisited: Another Brominated Diphenyl Ether

    Directory of Open Access Journals (Sweden)

    Bruce F. Bowden

    2005-03-01

    Full Text Available Abstract: A pentabrominated phenolic diphenyl ether (1 that has not previously been reported from marine sources has been isolated from Dysidea herbacea collected at Pelorus Island, Great Barrier Reef, Australia. The structure was determined by comparison of NMR data with those of known structurally-related metabolites. NMR spectral assignments for (1 are discussed in context with those of three previously reported isomeric pentabrominated phenolic diphenyl ethers.

  11. Imide/Arylene Ether Copolymers Containing Phosphine Oxide

    Science.gov (United States)

    Jensen, Brian J.; Partos, Richard D.

    1993-01-01

    Phosphine oxide groups react with oxygen to form protective phosphate surface layers. Series of imide/arylene ether block copolymers containing phosphine oxide units in backbone synthesized and characterized. In comparison with commercial polyimide, these copolymers display better resistance to etching by oxygen plasma. Tensile strengths and tensile moduli greater than those of polyarylene ether homopolymer. Combination of properties makes copolymers attractive for films, coatings, adhesives, and composite matrices where resistance to atomic oxygen needed.

  12. Advanced hybrid fluoropolymers from the cycloaddition of aryl trifluorovinyl ethers

    Science.gov (United States)

    Ligon, S. Clark, Jr.

    This dissertation discusses the synthesis of aryl trifluorovinyl ethers and their cycloaddition polymerization to give perfluorocyclobutyl (PFCB) polymers. To explore the stereochemistry of these polymers, simple monomfunctional aryl trifluorovinyl ethers were dimerized and the resultant cis and trans isomers were separated. Differences in structure help to improve understanding of the amorphous nature of the bulk PFCB polymeric material. To apply this knowledge, crown ether containing perfluorocyclobutyl (PFCB) polymers were synthesized for use in lithium ion battery applications. While poor solubility has hindered further development of these materials, slight modifications to structure may provide a solution. Also described is a fluorinated aryl vinyl ether and its attempted copolymerization with chlorotrifluoroethylene. While this copolymerization did not yield the desired materials, novel semifluorinated phenol precursors have been utilized in reactions with carboxylic acids to give polyesters and most recently with phosgene like species to give polycarbonates. Next, PFCB polymers were post functionalized with fluoroalkyl tethers to improve oleophobicity and hydrophobicity without decreasing thermal stability or optical clarity. In addition, various silica nanostructures were functionalized with aryl trifluorovinyl ethers. This includes the reaction of aryl silanes to give trifluorovinyl ether functional POSS and their polymerization to provide PFCB hybrid materials. Silane coupling agents were also used to functionalize colloidal silica and fumed silica nanoparticles. These procedures allow excellent dispersion of the silica nanoparticles throughout the fluoropolymer matrix. Finally, the reaction of aryl trifluorovinyl ether with nonfluorinated alkenes and alkynes was explored. In these reactions, the fluorinated olefin adds with the hydrocarbon olefin to give semifluorinated cyclobutanes (SFCB) and with the alkyne to give semifluorinated cyclobutene. The

  13. Review on Modification of Sulfonated Poly (-ether-ether-ketone Membranes Used as Proton Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Xiaomin GAO

    2015-11-01

    Full Text Available The proton exchange membrane fuel cell (PEMFC is a type of modern power, but the traditional proton exchange membranes (PEM of PEMFC are limited by high methanol permeability and water uptake. Poly-ether-ether-ketone (PEEK is a widely used thermoplastic with good cost-effective property. Sulfonated poly (-ether-ether-ketone (SPEEK has high electric conductivity and low methanol permeability, as well as comprehensive property, which is expected to be used as PEMs. However, the proton exchange ability, methanol resistance, mechanical property and thermal stability of SPEEK are closely related to the degree of sulfonation (DS of SPEEK membranes. Additionally, the proton conductivity, methanol permeability, and stability of SPEEK membranes applied in various conditions need to be further improved. In this paper, the research into modification of SPEEK membranes made by SPEEK and other polymers, inorganic materials are introduced. The properties and modification situation of the SPEEK and the composite membranes, as well as the advantages and disadvantages of membranes prepared by different materials are summarized. From the results we know that, the methanol permeability of SPEEK/PES-C membranes is within the order of magnitude, 10-7cm2/s. The proton conductivity of the SPPESK/SPEEK blend membrane reaches 0.212 S cm-1 at 80 °C. The cross-linked SPEEK membranes have raised thermal and dimensional stability. The non-solvent caused aggregation of the SPEEK ionomers. The proton conductivity of SPEEK/50%BMIMPF6/4.6PA membrane maintains stable as 2.0 x 10-2S cm-1 after 600 h at 160 °C. Incorporation of aligned CNT into SPEEK increases the proton conductivity and reduces the methanol permeability of the composite membranes. The PANI improves the hydrothermal stability. More proton transfer sites lead to a more compact structure in the composite membranes. According to the results, the proton exchange capacity, water uptake, and conductivity of

  14. Polybrominated diphenyl ethers and novel flame retardants

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Nielsen, Jesper Bo

    ,4,6-tribromophenyl ether (TBP-DBPE) and dechlorane plus (DDC-CO) have been detected in the same dust samples previously analysed for PBDEs and are currently being analysed in the corresponding human milk samples. [1] Stapleon H.M., Eagle S., Sjödin A., Webster T.F. (2012). Serum PBDEs in a North Carolina Toddler......, the objectives were to study whether i) the associations observed for plasma also existed for human milk, ii) the PBDE profiles in dust and milk could provide insights into the bioavailability and bioaccumulation of individual congeners, iii) NFRs were measurable in human milk, and iv) infants were exposed...... to significant amounts of NFRs via breast feeding. PBDEs were detected in all of the 40 milk samples analysed in this study. ΣPBDEtri-hepta ranged from 0.98-45.8 ng/g lw, with a median of 2.26 ng/g lw. The main congener in milk was BDE-153, accounting for 35% of ΣPBDEtri-hepta. This is much higher than in dust...

  15. Dimethyl ether (DME) as an alternative fuel

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.; Greene, Howard L.

    With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking non-petroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer-Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NO x, SO x, and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

  16. A General and Efficient Protocol for the Synthesis of Biaryl Ethers from Aryl Silyl Ethers Using Cs2CO3

    Institute of Scientific and Technical Information of China (English)

    CUI,Sun-Liang; WANG,Yan-Guang

    2004-01-01

    @@ Biary ethers are known to be important organic compounds for their biological interests and great presence in life science industries. A number of them have consequently provide a strong incentive for synthesis, which includes the classical Ullman reaction, metal-catalyzed substitution, SN-Ar based type, intramolecular oxidative coupling and MW-assisted methods. Although the above synthetic strategies are particularly important, a method is required for the direct conversion of phenoxy silane to biaryl ethers without recourse to hydrolytic conditions.

  17. Methylated β-Cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Madsen, Jens Christian

    2011-01-01

    groups at O2 promote complexation by extending the hydrophobic cavity. Like in the case of 2-hydroxypropylated cyclodextrins, the methyl substituents cause an increased release of ordered water from the hydration shell of the bile salts, resulting in a strong increase in both the enthalpy and the entropy...

  18. Molecular Design of Crown Ethers.22.Synthesis of Benzocrown Ether Derivatives and Their Solvent Extraction with Univalent/Bivalent Metal Picrates

    Institute of Scientific and Technical Information of China (English)

    YANG,Ying-Wei(杨英威); LI,Chun-Ju(李春举); ZHANG,Heng-Yi(张衡益); LIU,Yu(刘育)

    2004-01-01

    Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uniand bi-valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size-fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.

  19. Study on the reaction of ethyl 6-chloro-2-(chloromethyl) quinoline-3-carboxylate with amines%6-氯-2-氯甲基-3-喹啉甲酸乙酯与胺的反应研究

    Institute of Scientific and Technical Information of China (English)

    高文涛; 符鑫博; 李凯; 王东方; 赵雅楠; 李阳

    2015-01-01

    In the present investigation,ethyl 6-chloro-2-(chloromethyl)quinoline-3-carboxylate(1)as starting compound was subjec-ted to the reaction with different amines such as aromatic amines(2a-i),aliphatic amine(2j-m),and diamines(2n-p)to give the corresponding N-aryl-substituted(3a-i),N-alkyl-substituted(3j-m),and symmetrical N,N′-alkyl-bridged(3n-p)7-chloropyrrolo [3,4-b]quinolin-1-one derivatives,respectively,with good yields ranging 64. 8-77. 7%. The procedure had the advantages of simple operation,mild reaction. All of compounds were new and their structures were determined by IR,1 H NMR,13 C NMR, MS and HRMS.%以6-氯-2-氯甲基-3-喹啉甲酸乙酯(1)为底物,在溶剂无水乙醇中与胺及胺的衍生物2a-p反应,以较好的收率(64.8-77.7%)得到7-氯-2,3-二氢-1H-吡咯并[3,4-b]喹啉-1-酮衍生物,其中与芳胺反应生成N-芳基取代的化合物3a-i,与氨水、甲胺、乙胺和苄胺反应生成N-烷基取代的化合物3j-m,与乙二胺、丙二胺及丁二胺反应生成具有对称结构的化合物3 n-p.该反应具有操作简便、条件温和等特点.所有化合物均为新化合物,其结构经IR、1 H NMR、13 C NMR、MS和HRMS得以证实.

  20. UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui-chao; SUN Hui; LI Ang; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its applications to biological fields.PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP).The effects of BP,irradiation time and monomer concentration on the surface wettability of PEEK were investigated.Characterization of modified PEEK using scanning electron microscopy(SEM),energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP.With the increase in irradiation time and monomer concentration,contact angles decrease to as low as 30°,demonstrating a significant improvement of surface hydrophilicity.In agreement with the decrease in contact angle,under identical conditions,the nitrogen concentration increases,suggesting the increase in grafting degree of the grafting polymerization.This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer.Though the graft polymerization proceeds more readily in the presence of BP,the self-initiated graft polymerization is clearly observed.

  1. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    Science.gov (United States)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  2. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee

    2013-08-01

    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  3. Influence of Chemical Blends on Palm Oil Methyl Esters’ Cold Flow Properties and Fuel Characteristics

    Directory of Open Access Journals (Sweden)

    Obed M. Ali

    2014-07-01

    Full Text Available Alternative fuels, like biodiesel, are being utilized as a renewable energy source and an effective substitute for the continuously depleting supply of mineral diesel as they have similar combustion characteristics. However, the use of pure biodiesel as a fuel for diesel engines is currently limited due to problems relating to fuel properties and its relatively poor cold flow characteristics. Therefore, the most acceptable option for improving the properties of biodiesel is the use of a fuel additive. In the present study, the properties of palm oil methyl esters with increasing additive content were investigated after addition of ethanol, butanol and diethyl ether. The results revealed varying improvement in acid value, density, viscosity, pour point and cloud point, accompanied by a slight decrease in energy content with an increasing additive ratio. The viscosity reductions at 5% additive were 12%, 7%, 16.5% for ethanol, butanol and diethyl ether, respectively, and the maximum reduction in pour point was 5 °C at 5% diethyl ether blend. Engine test results revealed a noticeable improvement in engine brake power and specific fuel consumption compared to palm oil biodiesel and the best performance was obtained with diethyl ether. All the biodiesel-additive blend samples meet the requirements of ASTM D6751 biodiesel fuel standards for the measured properties.

  4. EtherCAT bus application in CNC system%EtherCAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计.

  5. O-Methyl cyclolaudenol

    Directory of Open Access Journals (Sweden)

    Nisar Hussain

    2009-06-01

    Full Text Available The title compound (systematic name: 3-methoxy-24-methyl-9,19-cyclolanost-25-ene, C32H54O, is a triterpenoid which has been isolated from Skimmia laureola. The three six-membered rings adopt chair, slightly distorted half-chair and distorted boat conformations, and the five-membered ring adopts an envelope conformation. All the rings are trans fused.

  6. Methylation in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Regina M. Santella

    2007-02-01

    Full Text Available

    The development of HCC is a complex, multistep, multistage process. The molecular pathogenesis of HCC appears to involve multiple genetic aberrations in the molecular control of hepatocyte proliferation, differentiation and death and the maintenance of genomic integrity. This process is influenced by the cumulative activation and inactivation of oncogenes, tumor suppressor genes and other genes. p53, a tumor suppressor gene, is the most frequently mutated gene in human cancers. There is also a striking sequence specific binding and induction of mutations by AFB1 at codon 249 of p53 in HCC.

    Epigenetic alterations are also involved in cancer development and progression. Methylation of promoter CpG islands is associated with inhibition of transcriptional initiation and permanent silencing of downstream genes.

    It is now known that most important tumor suppressor genes are inactivated, not only by mutations and deletions but also by promoter methylation. Several studies indicated that p16, p15, RASSF1A, MGMT, and GSTP1 promoter hypermethylation are prevalent in HCC. In addition, geographic variation in the methylation status of tumor DNA indicates that environmental factors may influence the frequent and concordant degree of hypermethylation in multiple genes in HCC and that epigeneticenvironmental interactions may be involved in hepatocarcinogenesis. We have found significant relationships between promoter methylation and AFB1-DNA adducts confirming the impact of environmental exposures on gene methylation.

    DNA isolated from serum or plasma of cancer patients frequently contains the same genetic and

  7. Crystal structures of bis[2-(diphenylphosphinothioylphenyl] ether and bis{2-[diphenyl(selanylidenephosphanyl]phenyl} ether

    Directory of Open Access Journals (Sweden)

    Daron E. Janzen

    2014-12-01

    Full Text Available The title compounds, C36H28OP2S2, (1, and C36H28OP2Se2, (2, exhibit remarkably similar structures although they are not isomorphous. The whole molecule of compound (2 is generated by twofold symmetry, with the ether O atom located on the twofold axis. Both compounds have intramolecular π–π interactions between terminal phenyl rings with centroid–centroid distances of 3.6214 (16 and 3.8027 (14 Å in (1 and (2, respectively. In the crystal of (1, short C—H...S hydrogen bonds link the molecules, forming chains along [001], while in (2 there are no analogous C—H...Se interactions present.

  8. Spontaneous Generation of Chirality in Simple Diaryl Ethers.

    Science.gov (United States)

    Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

    2015-07-01

    We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems.

  9. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  10. Synthesis and characterization of novel cellulose ether sulfates.

    Science.gov (United States)

    Rohowsky, Juta; Heise, Katja; Fischer, Steffen; Hettrich, Kay

    2016-05-20

    The synthesis and characterization of novel cellulose sulfate derivatives was reported. Various cellulose ethers were prepared in a homogeneous reaction with common sulfating agents. The received product possess different properties in dependence on the reaction conditions like sulfating agent, solvent, reaction time and reaction temperature. The cellulose ether sulfates are all soluble in water, they rheological behavior could be determined by viscosity measurements and the determination of the sulfur content by elemental analysis lead to a resulting degree of substitution ascribed to sulfate groups (DSSul) of the product. A wide range of products from DSSul 0.1 to DSSul 2.7 will be obtained. Furthermore the cellulose sulfate ethers could be characterized by Raman spectroscopy.

  11. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether.

    Science.gov (United States)

    Andrews, Ian P; Kwon, Ohyun

    2008-12-08

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethyl ethynyl ether using 0.1% palladium(0) catalyst and 1.0 equiv of tributyltin hydride. The product obtained is a mixture of regioisomers that can be carried forward with exclusive reaction of the beta-isomer. This method is highly reproducible; relative to previously reported procedures, it is more economical and involves a more facile purification procedure.

  12. Methylation profiling using methylated DNA immunoprecipitation and tiling array hybridization.

    Science.gov (United States)

    Cheung, Hoi-Hung; Lee, Tin-Lap; Rennert, Owen M; Chan, Wai-Yee

    2012-01-01

    DNA methylation is an important epigenetic modification that regulates development and plays a role in the pathophysiology of many diseases. It is dynamically changed during germline development. Methylated DNA immunoprecipitation (MeDIP) is an efficient, cost-effective method for locus-specific and genome-wide analysis. Methylated DNA fragments are enriched by a 5-methylcytidine-recognizing antibody, therefore allowing the analysis of both CpG and non-CpG methylation. The enriched DNA fragments can be amplified and hybridized to tiling arrays covering CpG islands, promoters, or the entire genome. Comparison of different methylomes permits the discovery of differentially methylated regions that might be important in disease- or tissue-specific expression. Here, we describe an established MeDIP protocol and tiling array hybridization method for profiling methylation of testicular germ cells.

  13. Activation of human ether-a-go-go-related gene potassium channels by the diphenylurea 1,3-bis-(2-hydroxy-5-trifluoromethyl-phenyl)-urea (NS1643)

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Diness, Thomas Goldin; Christ, Torsten

    2005-01-01

    repolarization current could be a new antiarrhythmic principle, because it possibly would attenuate afterdepolarizations, ischemic leak currents, and reentry phenomena. Repolarization of the cardiac myocytes is crucially dependent on the late rapid delayed rectifier current (I(Kr)) conducted by ether...... microM NS1643 activated I(Kr) and significantly decreased the action potential duration to 65% of the control values. The effect could be reverted by application of the specific HERG channel inhibitor 4'-[[1-[2-(6-methyl-2-pyridyl)ethyl]-4-piperidinyl]carbonyl]-methanesulfonanilide (E-4031) at 100 n...

  14. Event extraction for DNA methylation

    Directory of Open Access Journals (Sweden)

    Ohta Tomoko

    2011-10-01

    Full Text Available Abstract Background We consider the task of automatically extracting DNA methylation events from the biomedical domain literature. DNA methylation is a key mechanism of epigenetic control of gene expression and implicated in many cancers, but there has been little study of automatic information extraction for DNA methylation. Results We present an annotation scheme for DNA methylation following the representation of the BioNLP shared task on event extraction, select a set of 200 abstracts including a representative sample of all PubMed citations relevant to DNA methylation, and introduce manual annotation for this corpus marking nearly 3000 gene/protein mentions and 1500 DNA methylation and demethylation events. We retrain a state-of-the-art event extraction system on the corpus and find that automatic extraction of DNA methylation events, the methylated genes, and their methylation sites can be performed at 78% precision and 76% recall. Conclusions Our results demonstrate that reliable extraction methods for DNA methylation events can be created through corpus annotation and straightforward retraining of a general event extraction system. The introduced resources are freely available for use in research from the GENIA project homepage http://www-tsujii.is.s.u-tokyo.ac.jp/GENIA.

  15. Acid Catalyzed Condensation of Phenylethanal Enol or Thiol Enol Ether to 2-Phenylnaphthalene

    Institute of Scientific and Technical Information of China (English)

    CHANG, Yu-An

    2007-01-01

    Treatment of enol ether or thiol enol ether of phenylethanals with sulfuric or polyphosphoric acid in toluene or xylene gave 2-phenylnaphthalene in good yield. More importantly, a one-pot reaction has been developed.

  16. NARROW-DISPERSED CROSSLINKED CORE-SHELL POLYMER MICROSPHERES PREPARED BY SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Yu-zeng Zhao; Xin-lin Yang; Feng Bai; Wen-qiang Huang

    2005-01-01

    Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transfer radical polymerization (ATRP) was investigated. Polydivinylbenzene (PDVB) microspheres were prepared by dispersion polymerization with poly(N-vinyl pyrrolidone) (PVP) as stabilizer. The surfaces of PDVB microspheres were chloromethylated by chloromethyl methyl ether in the presence of zinc chloride as catalyst to form chloromethylbenzene initiating core sites for subsequent ATRP grafting of styrene using CuC1/bpy as catalytic system. Polystyrene was found to be grafted not only from the particle surfaces but also from within a thin shell layer, resulting in the formation of particles size increased from 2.38-2.58 μm, which can further grow to 2.93 μm during secondary grafting polymerization of styrene. This demonstrates that grafting polymerization proceeds through a typical ATRP procedure with living nature. All of the prepared microspheres have narrow particle size distribution with coefficient of variation around 10%.

  17. EtherCAT被纳入EUROMAP协议规范

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    7月10日,欧洲的塑料和橡胶机械制造商协会批准在其应用中采用EtherCAT技术:EtherCAT被纳入EUROMAP75协议规范,成为其底层的通讯技术。在该协议规范的第三部分,描述有该实时以太网系统的实施。

  18. EtherCAT以太网现场总线

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    EtherCAT为现场总线系统树立了新的性能标准。它具备灵活的网络拓扑结构,系统配置简单,和现场总线系统一样操作直观简便。另外,由于EtherCAT实现成本低廉,因此使系统得以在过去无法应用现场总线网络的应用场合中选用现场总线。

  19. ELMO驱动器获得EtherCAT审批

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    ELMO公司宣布其Gold伺服驱动器已通过严格的EtherCAT一致性测试,使得ELMO成为仅有的通过测试的六家公司之一。ELMO投入了大量的时间、财力和技术来遵守行业协议,如EtherCAT协议,以及诸如Safety和EMC这样的标准。ELMO认为,遵守协议是强制性的,以确保任何工业设备的可靠运行。

  20. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  1. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) ...

    Science.gov (United States)

    The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETBE assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for Ethyl Tertiary Butyl Ether (ETBE). The outcome of this project is a Toxicological Review and IRIS Summary for ETBE that will be entered into the IRIS database.

  2. Two Reaction Mechanisms via Iminium Ion Intermediates: The Different Reactivities of Diphenylprolinol Silyl Ether and Trifluoromethyl-Substituted Diarylprolinol Silyl Ether.

    Science.gov (United States)

    Gotoh, Hiroaki; Uchimaru, Tadafumi; Hayashi, Yujiro

    2015-08-24

    The reactions of α,β-unsaturated aldehydes with cyclopentadiene in the presence of diarylprolinol silyl ethers as catalyst proceed via iminium cations as intermediates, and can be divided into two types; one involving a Michael-type reaction (type A) and one involving a cycloaddition (type B). Diphenylprolinol silyl ethers and trifluoromethyl-substituted diarylprolinol silyl ethers, which are widely used proline-type organocatalysts, have been investigated in this study. As the LUMO of the iminium ion derived from trifluoromethyl-substituted diarylprolinol silyl ether is lower in energy than that derived from diphenylprolinol silyl ether, as supported by ab initio calculations, the trifluoromethyl-substituted catalyst is more reactive in a type B reaction. The iminium ion from an α,β-unsaturated aldehyde is generated more quickly with diphenylprolinol silyl ether than with the trifluoromethyl-substituted diarylprolinol silyl ether. When the generation of the iminium ion is the rate-determining step, the diphenylprolinol silyl ether catalyst is the more reactive. Because acid accelerates the generation of iminium ions and reduces the generation of anionic nucleophiles in the Michael-type reaction (type A), it is necessary to select the appropriate acid for specific reactions. In general, diphenylprolinol silyl ether is a superior catalyst for type A reactions, whereas the trifluoromethyl-substituted diarylprolinol silyl ether catalyst is preferred for type B reactions.

  3. Sulfoalkyl ether-alkyl ether cyclodextrin derivatives, their synthesis, NMR characterization, and binding of 6alpha-methylprednisolone.

    Science.gov (United States)

    Tongiani, Serena; Velde, David Vander; Ozeki, Tetsuya; Stella, Valentino J

    2005-11-01

    The objective of this study is to see if random alkyl ethers of various sulfoalkyl ether cyclodextrins can be synthesized and characterized. The purpose of the alkylation was to test the hypothesis that an increase in the "height" of a cyclodextrins cavity would help in the binding/complexation of larger more structurally complex molecules. The synthesis of new cyclodextrin derivatives comprising a mixture of sulfoalkyl ether and alkyl ether substituents on the same cyclodextrin ring was performed in aqueous alkaline solutions using various sultones and alkylsulfates. The method presented provided an easy and efficient way to modify cyclodextrins avoiding the use of organic solvents and high quantities of alkylating agents and could be carried out in either a two step or "one pot" single step process. Purification was by neutralization followed by ultrafiltration. The derivatives were characterized by 1D, ((1)H and (13)C), and a 2D NMR technique (HMQC, Heteronuclear Multiple Quantum Coherence). The combination of these techniques allowed an analysis of the degree of substitution and the site of substitution on the cyclodextrin (CD) nucleus. For both beta- and gamma-CD, sulfoakylation was preferred on the 2 > 3 > 6 hydroxyls while alkylation was preferred 6 > 2 > 3. Due to the simultaneous presence of short alkyl ether chains and negatively charged sulfoalkyl ether chains, these mixed water-soluble cyclodextrin derivatives, especially those of gamma-cyclodextrin, should be able to bind more complex drugs. The improved binding capacity of these new modified CDs with the model drug 6alpha-methylprednisolone is reported.

  4. 21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-lauryl vinyl ether copolymers. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1970 Vinyl chloride-lauryl vinyl ether copolymers. The vinyl chloride-lauryl vinyl ether copolymers identified in...

  5. EtherCAT技术协会宣布成立中国代表处

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    在北京一年一度的自动化展会FA/PA2007的高峰论坛上。EtherCAT技术协会(EtherCAT Technology Group,ETG)主席Martin Rostan先生宣布了EtherCAT技术协会中国代表处的成立。

  6. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  7. Synthesis and Properties of New-type Troponoid Dithio-Crown Ethers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropone 4 with bis (mer-captoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.

  8. Research of EtherCAT master based on Linux-RTAI%基于Linux-RTAI的EtherCAT主站研究

    Institute of Scientific and Technical Information of China (English)

    张少勋; 郗晓田

    2013-01-01

    工业以太网EtherCAT具有很好的实时性.为了进一步提高工业控制的实时性,本文创新性提出了基于Linux-RTAI的EtherCAT主站新架构;同时,详细阐述了其工作原理.最后在凌动D520工控机上进行测试,实验结果表明该架构具有极佳的实时性,非常适用于高实时控制场合.

  9. SULPHONATED POLY ETHER ETHER KETONE/POLYVINYL ALCOHOL/PHOSPHOTUNGSTIC ACID COMPOSITE MEMBRANES FOR PEM FUEL CELLS

    Institute of Scientific and Technical Information of China (English)

    S. Guhan; N.Arun Kumar; D.Sangeetha

    2009-01-01

    Composite membranes with polyvinyl alcohol (PVA),sulphonated poly ether ether ketone (SPEEK) and phosphotungstic acid (PWA) were prepared using solvent casting method.The proton conductivities of such membranes were found to be in the order of 10-3 S/cm in the fully hydrated condition at room temperature as measured by impedance spectroscopy.The crystalline properties were studied by X-ray diffraction analysis.The thermal properties were determined by TGA and DSC techniques.The tensile strength and percentage elongation were obtained from UTM studies.Water and methanol uptake of these membranes were studied.

  10. Direct synthesis of ethanol from dimethyl ether and syngas over combined H-Mordenite and Cu/ZnO catalysts.

    Science.gov (United States)

    Li, Xingang; San, Xiaoguang; Zhang, Yi; Ichii, Takashi; Meng, Ming; Tan, Yisheng; Tsubaki, Noritatsu

    2010-10-25

    Ethanol was directly synthesized from dimethyl ether (DME) and syngas with the combined H-Mordenite and Cu/ZnO catalysts that were separately loaded in a dual-catalyst bed reactor. Methyl acetate (MA) was formed by DME carbonylation over the H-Mordenite catalyst. Thereafter, ethanol and methanol were produced by MA hydrogenation over the Cu/ZnO catalyst. With the reactant gas containing 1.0% DME, the optimized temperature for the reaction was at 493 K to reach 100% conversion. In the products, the yield of methanol and ethanol could reach 46.3% and 42.2%, respectively, with a small amount of MA, ethyl acetate, and CO(2). This process is environmentally friendly as the main byproduct methanol can be recycled to DME by a dehydration reaction. In contrast, for the physically mixed catalysts, the low conversion of DME and high selectivity of methanol were observed.

  11. Comparative Environmental Performance of Two-Diesel-Fuel Oxygenates: Dibutyl Maleate (DBM) and Triproplyene Glycol Monomethyl Ether (TGME)

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D.W.; Marchetti, A.A.

    2001-10-01

    Many studies have shown that the addition of oxygen bearing compounds to diesel fuel can significantly reduce particulate emissions. To assist in the evaluation of the environmental performance of diesel-fuel oxygenates, we have implemented a suite of diagnostic models for simulating the transport of compounds released to air, water, and soils/groundwater as well as regional landscapes. As a means of studying the comparative performance of DBM and TGME, we conducted a series of simulations for selected environmental media. Benzene and methyl tertiary butyl ether (MTBE) were also addressed because they represent benchmark fuel-related compounds that have been the subject of extensive environmental measurements and modeling. The simulations showed that DBM and TGME are less mobile in soil because of reduced vapor-phase transport and increased retention on soil particles. The key distinction between these two oxygenates is that DBM is predicted to have a greater potential than TGME for aerobic biodegradation, based on chemical structure.

  12. HYDROPHILIC MODIFICATION OF PPESK POROUS MEMBRANES VIA AQUEOUS SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhuan Yi; You-yi Xu; Li-ping Zhu; Han-bang Dong; Bao-ku Zhu

    2009-01-01

    Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone)(PPESK)porous membranes was achieved via surface-initiated atom transfer radical polymerization(ATRP)in aqueous medium.Prior to ATRP,chloromethyl groups were introduced onto PPESK main chains by chloromethylation.Chloromethylated PPESK(CMPPESK)was fabricated into porous membrane through phase inversion technique.Hydrophilic poly(poly(ethylene glycol)methyl ether methacrylate)(P(PEGMA))brushes were grafted from CMPPESK membrane under the initiation of benzyl chloride groups on membrane surface.The results of Fourier transform infrared(FT-IR)spectroscopy and X-ray photoelectron spectroscopy (XPS)confirmed the grafting of P(PEGMA)chains.Water contact angle measurements and protein adsorption experiments suggested that the hydrophilicity and anti-fouling ability of PPESK membrane were remarkably improved after the grafting of P(PEGMA)brushes.The addition of small amount of water in the reaction solvent apparently accelerated the progress of the grafting reaction.The use of CuCl2 in the catalyst system promoted the controllability of the ATRP reaction.

  13. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety...

  14. The effect of gasses on the viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen

    2008-01-01

    Dimethyl ether (DME) has been recognised as a clean substitute for diesel oil as it does not form soot during combustion. DME has a vapour pressure of 6 bar at 25 degrees C; so pressurisation is necessary to keep DME liquid at ambient temperature. Inert gases are good candidates as pressurising m...

  15. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  16. Anthracylmethyl Benzoazacrown Ether as Selective Fluorescence Sensors for Zn2+

    Institute of Scientific and Technical Information of China (English)

    Li Hua JIA; Xiang Feng GUO; Yuan Yuan LIU; Xu Hong QIAN

    2004-01-01

    A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.

  17. Functionalization of thiocrown ethers containing the thioacetal unit

    NARCIS (Netherlands)

    Buter, Jan; Meijer, Renzo H.; Kellogg, Richard M.; Meijer, H.C.

    1998-01-01

    Thiocrown ethers containing thioacetal units are readily prepared by reaction of the cesium salts of long chain dithiols with methylene dibromide. Preparation of the trimethylsilyl derivatives followed by condensation with aldehydes under basic conditions (Peterson reaction) leads to the expected ma

  18. Why do crown ethers activate enzymes in organic solvents?

    NARCIS (Netherlands)

    Unen, van Dirk-Jan; Engbersen, Johan F.J.; Reinhoudt, David N.

    2002-01-01

    One of the major drawbacks of enzymes in nonaqueous solvents is that their activity is often dramatically low compared to that in water. This limitation can be largely overcome by crown ether treatment of enzymes. In this paper, we describe a number of carefully designed new experiments that have im

  19. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed...

  20. Conversion Excess Coal Gas to Dimethyl Ether in Steel Works

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the technical progress of metallurgical industry, more excess gas will be produced in steel works. The feasibility of producing dimethyl ether by gas synthesis was discussed, which focused on marketing, energy balance, process design, economic evaluation, and environmental protection etc. DME was considered to be a new way to utilize excess coal gas in steel works.

  1. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    Directory of Open Access Journals (Sweden)

    Juan Fernández-Bolaños

    2009-05-01

    Full Text Available The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  2. Antiknock evaluation of hydrocarbons and ethers as aviation fuel components

    Science.gov (United States)

    Barnett, Henry C

    1950-01-01

    The results of a NACA investigation conducted over a period of several years to evaluate the anti-knock characteristics of organic compounds are summarized. Included are data for 18 branched paraffins and olefins, 27 aromatics, and 22 ethers. The factors of performance investigated were blending characteristics, temperature sensitivity, lead response, and relation between molecular structure and antiknock ratings. Four engines were used.

  3. Ether lipids of planktonic archae in the marine water column

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hoefs, M.J.L.; Schouten, S.; King, L.L.; Wakeham, S.G.; Leeuw, J.W. de

    1997-01-01

    Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize a

  4. Lithium air batteries having ether-based electrolytes

    Science.gov (United States)

    Amine, Khalil; Curtiss, Larry A.; Lu, Jun; Lau, Kah Chun; Zhang, Zhengcheng; Sun, Yang-Kook

    2016-10-25

    A lithium-air battery includes a cathode including a porous active carbon material, a separator, an anode including lithium, and an electrolyte including a lithium salt and polyalkylene glycol ether, where the porous active carbon material is free of a metal-based catalyst.

  5. Isotope effects of hafnium in solvent extraction using crown ethers

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Toshiyuki; Moriyama, Hirotake [Research Reactor Institute, Kyoto University, Osaka (Japan); Hirata, Takafumi [Laboratory for Planetary Sciences, Tokyo Institute of Technology, Tokyo (Japan); Nishizawa, Kazushige [Department of Nuclear Engineering, Graduate School of Engineering, Osaka University, Osaka (Japan)

    2001-06-01

    Hafnium isotopes were fractionated in a liquid-liquid extraction system by using seven types of crown ethers, tributyl phosphate, or {omicron}-diethoxybenzene. The largest isotope effect was observed in the isotope pair of {sup 177}Hf-{sup 179}Hf with dibenzo-24-crown-8; the isotope enrichment factor was observed to be 0.0129{+-}0.0032. (author)

  6. Bio-inspired ion selective crown-ether polymer membranes

    NARCIS (Netherlands)

    Tas, Sinem

    2016-01-01

    Development of unctional membranes that are capable of selectively recognizing and transporting ions have key importance for the recovery and separation of specific icons (e.d. K+, Li+, Na+) from multicomponent mixtures. In this thesis, new membrane materials based on crown ether-metal ion host-gues

  7. Study on the Multi-axis Motion Controller Based on EtherCAT%基于EtherCAT的多轴运动控制器研究

    Institute of Scientific and Technical Information of China (English)

    刘艳强; 王健; 单春荣

    2008-01-01

    研究了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的实现方法.并在此基础上实现了一种基于EtherCAT的多轴运动控制器,用于数控设备和工业机器人的控制.

  8. EtherCAT-Industrial Ethernet Fieldbus and Its Driver Design%工业以太网现场总线EtherCAT及驱动程序设计

    Institute of Scientific and Technical Information of China (English)

    单春荣; 刘艳强; 郇极

    2007-01-01

    EtherCAT是一种新型的实时工业以太网现场总线.文章介绍了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的配置方法、主站和从站驱动程序设计技术等.

  9. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUPS.Ⅱ.SYNTHESIS OF NETROWK CROWN ETHER POLYMER WITH PENDANT SULFIDE SIDE CHAIN AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHENYuanyin; MENGLingzhi; 等

    1995-01-01

    Network crown ether polymer with pendant sulfide side chain in the network structure units has been synthesized via ring-opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether.A kind of active catalyst suitable for this reaction was suggested.The title polymer was found to be a good ligand for platinous chloride,and the platinous complex could catalyze the hydrosilylation of ole fins with triethoxysilane efficiently.

  10. Ether CAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计。

  11. A mild and efficient procedure for the synthesis of ethers from various alkyl halides

    Directory of Open Access Journals (Sweden)

    Mosstafa Kazemi

    2013-10-01

    Full Text Available A simple, mild and practical procedure has been developed for the synthesis of symmetrical and unsymmetrical ethers by using DMSO, TBAI in the presence of K2CO3. We extended the utility of Potassium carbonate as an efficient base for the preparation of ethers. A wide range of alkyl aryl and dialkyl ethers are synthezied from treatment of aliphatic alcohols and phenols with various alkyl halides in the prescence of efficient base Potassium carbonate. Secondary alkyl halides were easily converted to corresponding ethers in releatively good yields . This is a mild, simple and practical procedure for the preparation of ethers in high yields and suitable times under mild condition.

  12. Comparative photophysical behaviour of naphthalene-linked crown ethers and aza crown ethers of varying cavity dimensions

    Indian Academy of Sciences (India)

    Subhodip Samanta; Pinki Saha Sardar; Shyam Sundar Maity; Anirban Pal; Maitrayee Basu Roy; Sanjib Ghosh

    2007-03-01

    A comparative time-resolved emission studies of several naphtho-crown ethers I-V, where metal ions can be complexed in a predetermined orientation with respect to the naphthalene (Naph) - plane and naphthalene-linked aza crown ethers (L1 and L2) have been presented. In both the systems, crown ethers and aza crown ethers, naphthalene fluorescence gets quenched. In the systems I to V, the quenching is mainly due to efficient spin-orbit coupling (SOC) leading to greater population of the lowest triplet state of naphthalene. This SOC depends on the orientation of the crown ring with respect to the Naph--plane. However, in the systems L1 and L2, the quenching is due to photoinduced electron transfer (PET) from nitrogen lone pair of the aza crown ring to naphthalene moiety and consequent exciplex formation. The results have been interpreted using the time-resolved emission studies of all the compounds in various solvents, their alkali metal ion complexes, and protonated ligands.

  13. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  14. Designed poly(ether-imide)s and fluoro-copoly(ether-imide)s: Synthesis, characterization and their film properties

    Energy Technology Data Exchange (ETDEWEB)

    Vora, Rohitkumar H. [Advanced Polymer Research and Technologies, 505 Cinder Road, Edison, NJ 08820 (United States)]. E-mail: rohitvora@apr-technologies.com; Goh, Suat Hong [Department of Chemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2006-07-25

    Two series of amorphous fluoro-poly(ether-imide) (6F-PEI) and one series of fluoro-coploy(ether-imide) (6F-CoPEI) polymers based on 2,2'-bis(3,4-dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di-ether-containing diamines: 1,2'-bis(4-aminophenoxy)benzene (o-BAPOB) and 4,4'-bis(4-aminophenoxy)diphenyl sulfone (p-SED) were synthesized. The solution properties, chemical resistance, thermal stability, mechanical properties, thermo-oxidative and hydrolytic stability of selected 6F-PEIs and 6F-CoPEIs were studied. The dielectric constant ({epsilon}') values of 6F-PEI and 6F-CoPEI were estimated by additive group contribution calculation using mathematical equations defined by the Lorentz-Lorenz's theory and the Vogel's theory, and by Vora-Wang equations, respectively. These polymers not only showed excellent electrical properties but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides. The estimated dielectric constant of these polymers ({epsilon}' < 3.15) were lower than those of commercially available poly(ether-imide) ULTEM[reg] 1000 and polyimides Kapton[reg] H, respectively at 1 kHz. The analytical results are summarized and discussed.

  15. Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

    Science.gov (United States)

    A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

  16. DNA methylation in metabolic disorders

    DEFF Research Database (Denmark)

    Barres, Romain; Zierath, Juleen R

    2011-01-01

    DNA methylation is a major epigenetic modification that controls gene expression in physiologic and pathologic states. Metabolic diseases such as diabetes and obesity are associated with profound alterations in gene expression that are caused by genetic and environmental factors. Recent reports...... have provided evidence that environmental factors at all ages could modify DNA methylation in somatic tissues, which suggests that DNA methylation is a more dynamic process than previously appreciated. Because of the importance of lifestyle factors in metabolic disorders, DNA methylation provides...... a mechanism by which environmental factors, including diet and exercise, can modify genetic predisposition to disease. This article considers the current evidence that defines a role for DNA methylation in metabolic disorders....

  17. DNA methylation and carcinogenesis.

    Science.gov (United States)

    Lichtenstein, A V; Kisseljova, N P

    2001-03-01

    In the world of easy things truth is opposed to lie; in the world of complicated things one profound truth is opposed to another not less profound than the first. Neils Bohr The hypothesis of the exclusively genetic origin of cancer ("cancer is a disease of genes, a tumor without any damage to the genome does not exist") dominated in the oncology until recently. A considerable amount of data confirming this hypothesis was accumulated during the last quarter of the last century. It was demonstrated that the accumulation of damage of specific genes lies at the origin of a tumor and its following progression. The damage gives rise to structural changes in the respective proteins and, consequently, to inappropriate mitogenic stimulation of cells (activation of oncogenes) or to the inactivation of tumor suppressor genes that inhibit cell division, or to the combination of both (in most cases). According to an alternative (epigenetic) hypothesis that was extremely unpopular until recently, a tumor is caused not by a gene damage, but by an inappropriate function of genes ("cancer is a disease of gene regulation and differentiation"). However, recent studies led to the convergence of these hypotheses that initially seemed to be contradictory. It was established that both factors--genetic and epigenetic--lie at the origin of carcinogenesis. The relative contribution of each varies significantly in different human tumors. Suppressor genes and genes of repair are inactivated in tumors due to their damage or methylation of their promoters (in the latter case an "epimutation", an epigenetic equivalent of a mutation, occurs, producing the same functional consequences). It is becoming evident that not only the mutagens, but various factors influencing cell metabolism, notably methylation, should be considered as carcinogens.

  18. New amphiphilic PEG-b-P(ester-ether) micelles as potential drug nanocarriers

    Energy Technology Data Exchange (ETDEWEB)

    Jeetah, Roubeena; Bhaw-Luximon, Archana; Jhurry, Dhanjay, E-mail: dhanjay.jhurry@gmail.com [University of Mauritius, ANDI Centre of Excellence for Biomedical and Biomaterials Research, MSIRI Building (Mauritius)

    2012-10-15

    A range of diblock and triblock copolymers of dioxanone and methyl dioxanone (MeDX) were synthesized by ring-opening polymerization of dioxanone and MeDX initiated by hydroxyl-terminated PEG (MPEG) or di-amino-terminated PEG (Jeffamine{sup Registered-Sign }) as macroinitiator in the presence of Sn(Oct){sub 2}. The copolymers exhibit amphiphilic behavior in water forming core-shell micelles in the size range 120-300 nm as measured by DLS. DSC measurements exhibit only one melting transition for all copolymers and confirm that increasing MeDX content of the copolymers lead to decreasing crystalline character and hydrophobic-hydrophilic chain entanglement. Anti-inflammatory drug ketoprofen was successfully loaded into the hydrophobic core of the micelles. Various key parameters such as micelle size, drug entrapment efficiency and drug release, which are dependent on crystalline structure and biodegradability characteristics of the hydrophobic core, could effectively be controlled by varying the dioxanone/MeDX ratio of the (ester-ether) copolymer.

  19. Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

    Directory of Open Access Journals (Sweden)

    Yann Schrodi

    2012-05-01

    Full Text Available The reactions between several derivatives of 1-(3,5-dimethoxyphenyl-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh33 and RuCl2(p-cymene(L, where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-n-propylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes.

  20. Anode reaction mechanism and crossover in direct dimethyl ether fuel cell

    Science.gov (United States)

    Mizutani, Itsuko; Liu, Yan; Mitsushima, Shigenori; Ota, Ken-ichiro; Kamiya, Nobuyuki

    The anode reaction mechanism and the crossover of a direct dimethyl ether fuel cell (DDMEFC) have been investigated. This was done by considering the anode products of the half-cell and DDMEFC experiments. It was found that the CO 2 current efficiency of the DDMEFC was almost 1 at 30-80 °C and that this value was higher than that of a DMFC. The main by-products of the DDMEFC were methyl formate and methanol whose amounts are negligibly small compared to CO 2. With respect to crossover, the influence of DME on the oxygen reduction reaction (ORR) was examined with a half-cell, and the amount of crossover of DME was measured while operating an actually constructed DDMEFC. From these experiments, it was found that DME does not influence the ORR as much as methanol under similar conditions. Furthermore, the amount of crossover of DME decreased with an increase in temperature and current density and it was one-half that of methanol on open circuit and at 80 °C. The CO 2 current efficiency of the DDMEFC is higher than that of a DMFC, and the influence of crossover in the DDMEFC is less than that in the DMFC. Since the temperature dependence of the reactivity of DME is larger than that of methanol, the higher output is expected for the DDMEFC at the elevated temperature. Therefore, the DDMEFC has a promising potential as a portable power source in the future.

  1. Conjugation of the mycotoxins alternariol and alternariol monomethyl ether in tobacco suspension cells.

    Science.gov (United States)

    Hildebrand, Andreas A; Kohn, Beate N; Pfeiffer, Erika; Wefers, Daniel; Metzler, Manfred; Bunzel, Mirko

    2015-05-20

    The mycotoxins alternariol (AOH) and alternariol-9-O-methyl ether (AME) carry three and two phenolic hydroxyl groups, respectively, which makes them candidates for the formation of conjugated metabolites in plants. Such conjugates may escape routine methods of analysis and have therefore been termed masked or, more recently, modified mycotoxins. We report now that AOH and AME are extensively conjugated in suspension cultures of tobacco BY-2 cells. Five conjugates of AOH were identified by MS and NMR spectroscopy as β-D-glucopyranosides (attached in AOH 3- or 9-position) as well as their 6'-malonyl derivatives, and as a gentiobiose conjugate. For AME, conjugation resulted in the d-glucopyranoside (mostly attached in the AME 3-position) and its 6'- and 4'-malonyl derivatives. Pronounced differences were noted for the quantitative pattern of AOH and AME conjugates as well as for their phytotoxicity. Our in vitro study demonstrates for the first time that masked mycotoxins of AOH and AME can be formed in plant cells.

  2. Recovery of Bio-Oil from Industrial Food Waste by Liquefied Dimethyl Ether for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Kiyoshi Sakuragi

    2016-02-01

    Full Text Available The development of new energy sources has become particularly important from the perspective of energy security and environmental protection. Therefore, the utilization of waste resources such as industrial food wastes (IFWs in energy production is expected. The central research institute of electric power industry (CRIEPI, Tokyo, Japan has recently developed an energy-saving oil-extraction technique involving the use of liquefied dimethyl ether (DME, which is an environmentally friendly solvent. In this study, three common IFWs (spent coffee grounds, soybean, and rapeseed cakes were evaluated with respect to oil yield for biodiesel fuel (BDF production by the DME extraction method. The coffee grounds were found to contain 16.8% bio-oil, whereas the soybean and rapeseed cakes contained only approximately 0.97% and 2.6% bio-oil, respectively. The recovered oils were qualitatively analysed by gas chromatography-mass spectrometry. The properties of fatty acid methyl esters derived from coffee oil, such as kinematic viscosity, pour point, and higher heating value (HHV, were also determined. Coffee grounds had the highest oil content and could be used as biofuel. In addition, the robust oil extraction capability of DME indicates that it may be a favourable alternative to conventional oil extraction solvents.

  3. Formation of Methanol and Dimethyl Ether in Dielectric Barrier Disch arges

    Science.gov (United States)

    Kogelschatz, Ulrich

    1996-10-01

    The generation of liquid fuels like methanol (MeOH) and dimethyl ether (DME) from the greenhouse gases (GHG) methane and carbon dioxide has recently attracted growing attention. Investigations of this kind are part of efforts to reduce GHG emissions to the atmosphere. For our investigations we used a tubular dielectric barrier discharge reactor with an annular discharge gap of 1 mm width and a cylindrical quartz dielectric of 2.5 mm thickness. It was operated in methane-oxygen mixtures at pressures between 1 and 4 bar. The discharge was operated at a frequency of about 18 kHz. The power density could be raised up to 20 kW/m^2 of electrode area by increasing the applied voltage. Up to 1.3% MeOH and .4% DME were measured after a single passage through a discharge gap of 310 mm length by GC and GC/MS detection. These values were obtained at 2 bar, substantially lower values were measured at 1 or 4 bar operating pressure. At high specific energies >8 eV per molecule of feed gas the MeOH concentration decreased and methyl formate appeared in the product stream.

  4. Reactive phase inversion for manufacture of asymmetric poly (ether imide sulfone) membranes

    KAUST Repository

    Jalal, Taghreed

    2014-12-01

    Poly (ether imide sulfone) membranes were manufactured by combining phase inversion and functionalization reaction between epoxy groups and amine modified polyether oligomers (Jeffamine) or TiO2 nanoparticles. Polysilsesquioxanes containing epoxy functionalities were in-situ grown in the casting solution and made available for further reaction with amines in the coagulation/annealing baths. The membranes were characterized by field emission scanning electron microscopy, porosimetry and water flux measurements. Water permeances up to 1500 l m-2 h-1 bar-1 were obtained with sharp pore size distribution and a pore diameter peak at 66 nm, confirmed by porosimetry, which allowed 99.2% rejection of γ-globulin. Water flux recovery of 77.5% was achieved after filtration with proteins. The membranes were stable in 50:50 dimethylformamide/water, 50:50 N-methyl pyrrolidone/water and 100% tetrahydrofuran. The possibility of using similar concept for homogeneous and stable attachment of nanoparticles on the membrane surface was demonstrated.

  5. Degradation of various alkyl ethers by alkyl ether-degrading Actinobacteria isolated from activated sludge of a mixed wastewater treatment.

    Science.gov (United States)

    Kim, Yong-Hak; Cha, Chang-Jun; Engesser, Karl-Heinrich; Kim, Sang-Jong

    2008-11-01

    Various substrate specificity groups of alkyl ether (AE)-degrading Actinobacteria coexisted in activated sewage sludge of a mixed wastewater treatment. There were substrate niche overlaps including diethyl ether between linear AE- and cyclic AE-degrading strains and phenetole between monoalkoxybenzene- and linear AE-degrading strains. Representatives of each group showed different substrate specificities and degradation pathways for the preferred substrates. Determining the rates of initial reactions and the initial metabolite(s) from whole cell biotransformation helped us to get information about the degradation pathways. Rhodococcus sp. strain DEE5311 and Rhodococcus rhodochrous strain 117 both were able to degrade anisole and phenetole through aromatic 2-monooxygenation to form 2-alkoxyphenols. In contrast, diethyl ether-oxidizing strain DEE5311 capable of degrading a broad range of linear AE, dibenzyl ether and monoalkoxybenzenes initially transformed anisole and phenetole to phenol via direct O-dealkylation. Compared to this, cyclic AE-degrading Rhodococcus sp. strain THF100 preferred tetrahydrofuran (265 ± 35 nmol min(-1)mg(-1) protein) to diethyl ether (diethoxybenzene-degrading Rhodococcus sp. strain DEOB100 and Gordonia sp. strain DEOB200 transformed 1,3-/1,4-dialkoxybenzenes to 3-/4-alkoxyphenols by similar manners in the order of rates (nmol min(-1) mg(-1) protein): 1,4-diethoxybenzene (11.1 vs. 3.9)>1,4-dimethoxybenzene (1.6 vs. 2.6)>1,3-dimethoxybenzene (0.6 vs. 0.6). This study suggests that the AE-degrading Actinobacteria can orchestrate various substrate specificity responses to the degradation of various categories of AE pollutants in activated sludge communities.

  6. In-Solution Conformational Analysis of the XCYCH3 Moiety for Small Esters and Ethers with all Combinations of X, Y = O, S

    Directory of Open Access Journals (Sweden)

    Peter I. Nagy

    2013-07-01

    Full Text Available Favorable steric and electrostatic fit of a ligand to a receptor is of central interest in theoretical drug design. This paper considers the effects of non-protic solvents, in comparison with the gas phase, on the preferred conformation of the XCYCH3 moiety of simple aliphatic esters and heterocyclic methyl ethers with all combinations of the X and Y atoms as oxygen and sulfur. An IEF-PCM/B97D/aug-cc-pv(t+dz continuum dielectric solvent study in chloroform and acetonitrile explores the through-space polarization effect of the environment on the conformational preference, not affected by possible solute-solvent hydrogen bond formation. The inherently favored structure for the present molecules is important, since the hypothetical oxygen and sulfur lone-pairs point approximately in opposite directions in the cis conformation of esters, whereas the trans and gauche conformations for the methyl group in ethers define nearly parallel or perpendicular directionality for the lone pairs of the ring heteroatoms and the O or S atoms connecting to the ring. These different preferences for the studied two families of compounds allow for designing formation of hydrogen bonds with a protein in fairly different regions of the latter still within the ligand-binding cavity. For a fine-tuning of these hydrogen bonds, a replacement of an oxygen atom of the ligand by a sulfur atom could be a straightforward possibility.

  7. EtherCAT高性能从站的设计与实现%Design and implementation of EtherCAT high performance slave station

    Institute of Scientific and Technical Information of China (English)

    任计羽; 范永坤; 熊皑

    2014-01-01

    The use of dedicated EtherCAT slave chip leads to high cost, low hardware integration, software complexity and difficulty in debugging, so a new hardware and software design method of EtherCAT slave station was presented. In the method, the AM3359 ARM chip was used, in which all functions including EtherCAT slave communication and application layer ware achieved, so the hardware cost was greatly reduced. A layered approach was used in software design, so it became simple and convenient to program and debug software. EtherCAT slave was implemented, at the same time, a EtherCAT network was designed to test and analyze the performance of EtherCAT slave. The EtherCAT slave station could work well.%针对使用专用芯片导致EtherCAT从站成本增加、硬件集成度下降、软件复杂、调试困难的问题,提出了新的EtherCAT从站软硬件设计方法。该方法使用AM3359 ARM芯片,在一块芯片内实现了EtherCAT从站通信功能和应用层功能,使硬件成本降低;使用分层的软件设计方法,软件编程简单,调试方便。通过搭建EtherCAT测试网络对所设计的从站功能进行测试,从站能够完好地工作。

  8. Mechanisms and kinetics of noncatalytic ether reaction in supercritical water. 2. Proton-transferred fragmentation of dimethyl ether to formaldehyde in competition with hydrolysis.

    Science.gov (United States)

    Nagai, Yasuharu; Matubayasi, Nobuyuki; Nakahara, Masaru

    2005-04-28

    Noncatalytic reaction pathways and rates of dimethyl ether (DME) in supercritical water are determined in a tube reactor made of quartz according to liquid- and gas-phase 1H and 13C NMR observations. The reaction is studied at two concentrations (0.1 and 0.5 M) in supercritical water at 400 degrees C and over a water-density range of 0.1-0.6 g/cm3. The supercritical water reaction is compared with the neat one (in the absence of solvent) at 0.1 M and 400 degrees C. DME is found to decompose through (i) the proton-transferred fragmentation to methane and formaldehyde and (ii) the hydrolysis to methanol. Formaldehyde from reaction (i) is consecutively subjected to four types of redox reactions. Two of them proceed even without solvent: (iii) the unimolecular proton-transferred decarbonylation forming hydrogen and carbon monoxide and (iv) the bimolecular self-disproportionation generating methanol and carbon monoxide. When the solvent water is present, two additional paths are open: (v) the bimolecular self-disproportionation of formaldehyde with reactant water, producing methanol and formic acid, and (vi) the bimolecular cross-disproportionation between formaldehyde and formic acid, yielding methanol and carbonic acid. Methanol is produced through the three types of disproportionations (iv)-(vi) as well as the hydrolysis (ii). The presence of solvent water decelerates the proton-transferred fragmentation of DME; the rate constant is reduced by 40% at 0.5 g/cm3. This is caused by the suppression of low-frequency concerted motion corresponding to the reaction coordinate for the simultaneous C-O bond scission and proton transfer from one methyl carbon to the other. In contrast to the proton-transferred fragmentation, the hydrolysis of DME is markedly accelerated by increasing the water density. The latter becomes more important than the former in supercritical water at densities greater than 0.5 g/cm3.

  9. Percutaneous penetration of methyl nicotinate from ointments using the laser Doppler technique: bioequivalence and enhancer effects.

    Science.gov (United States)

    Remane, Yvonne; Leopold, Claudia S; Maibach, Howard I

    2006-12-01

    Laser Doppler flowmetry (LDF) may be used to quantify erythema response as a result of an increased cutaneous microcirculation induced by methyl nicotinate (MN). Bioequivalence of a test and a standard preparation (vehicles: light mineral oil and medium chain triglycerides, respectively) was confirmed according to the pilot study of the FDA Guidance for Industry "Topical dermatologic corticosteroids: In Vivo bioequivalence" applying the staggered application and synchronized removal method for one defined concentration. Furthermore, the influence of penetration enhancers (5% w/w Dimethylsulfoxide (DMSO) and 10% w/w diethylene glycol monoethyl ether) on MN penetration was investigated. It was shown that DMSO and diethylene glycol monoethyl ether altered cutaneous microcirculation and thus MN penetration in comparison to the standard formulation. However, true penetration enhancement could only be proved with diethylene glycol monoethyl ether resulting from an improved drug solubility in the skin which was confirmed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Increased MN penetration by DMSO was only caused by thermodynamic effects, i.e. a decreased drug solubility in the vehicle.

  10. Methylation-Specific PCR Unraveled

    Directory of Open Access Journals (Sweden)

    Sarah Derks

    2004-01-01

    Full Text Available Methylation‐specific PCR (MSP is a simple, quick and cost‐effective method to analyze the DNA methylation status of virtually any group of CpG sites within a CpG island. The technique comprises two parts: (1 sodium bisulfite conversion of unmethylated cytosine's to uracil under conditions whereby methylated cytosines remains unchanged and (2 detection of the bisulfite induced sequence differences by PCR using specific primer sets for both unmethylated and methylated DNA. This review discusses the critical parameters of MSP and presents an overview of the available MSP variants and the (clinical applications.

  11. Structural Study of Mismatched Disila-Crown Ether Complexes

    Directory of Open Access Journals (Sweden)

    Kirsten Reuter

    2017-02-01

    Full Text Available Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2 and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4. In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the large Ba2+ ion by the relatively small ligand 1,2-disila[15]crown-5—was investigated, yielding the dinuclear complex 5. This structure represents a first outlook on sandwich complexes based on hybrid crown ethers.

  12. SYNTHESIS OF ALLYL PHENYL ETHER AND CLAISEN REARRANGEMENT

    Directory of Open Access Journals (Sweden)

    Gagik Torosyan

    2011-12-01

    Full Text Available It has been established the possibility for phenol allylation on natural zeolites and them analogs. Here is demonstrated the synthesis of allyl phenol, which has wide industrial applications. The offered method in comparison with the traditional methods has more advantages – higher selectivity, smaller material and power resources consumption. It has been obtained the mixture of allylating phenols (30% in general with allyl phenyl ether (1 with 80% yields. At 600 K is obtained allylphenyl ether, at 700 K beginning the formation of allyl phenols, which is the result of direct C-allylation of the aromatic ring. It has been investigated the possibility of Claisen rearrangement in the same conditions. All of that are established by gas-liquid chromatography and liquid chromatography data.

  13. Synthesis of Ethers via Reaction of Carbanions and Monoperoxyacetals

    Science.gov (United States)

    2015-01-01

    Although transfer of electrophilic alkoxyl (“RO+”) from organic peroxides to organometallics offers a complement to traditional methods for etherification, application has been limited by constraints associated with peroxide reactivity and stability. We now demonstrate that readily prepared tetrahydropyranyl monoperoxyacetals react with sp3 and sp2 organolithium and organomagnesium reagents to furnish moderate to high yields of ethers. The method is successfully applied to the synthesis of alkyl, alkenyl, aryl, heteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters. In contrast to reactions of dialkyl and alkyl/silyl peroxides, the displacements of monoperoxyacetals provide no evidence for alkoxy radical intermediates. At the same time, the high yields observed for transfer of primary, secondary, or tertiary alkoxides, the latter involving attack on neopentyl oxygen, are inconsistent with an SN2 mechanism. Theoretical studies suggest a mechanism involving Lewis acid promoted insertion of organometallics into the O–O bond. PMID:26560686

  14. [Ethylene glycol and propylene glycol ethers - Reproductive and developmental toxicity].

    Science.gov (United States)

    Starek-Świechowicz, Beata; Starek, Andrzej

    2015-01-01

    Both ethylene and propylene glycol alkyl ethers (EGAEs and PGAEs, respectively) are widely used, mainly as solvents, in industrial and household products. Some EGAEs demonstrate gonadotoxic, embriotoxic, fetotoxic and teratogenic effects in both humans and experimental animals. Due to the noxious impact of these ethers on reproduction and development of organisms EGAEs are replaced for considerably less toxic PGAEs. The data on the mechanisms of testicular, embriotoxic, fetotoxic and teratogenic effects of EGAEs are presented in this paper. Our particular attention was focused on the metabolism of some EGAEs and their organ-specific toxicities, apoptosis of spermatocytes associated with changes in the expression of various genes that code for oxidative stress factors, protein kinases and nuclear hormone receptors.

  15. Intrinsic Kinetics of Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    Zhaoguang Nie; Hongwei Liu; Dianhua Liu; Weiyong Ying; Dingye Fang

    2005-01-01

    The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over a methanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in a tubular integral reactor at 3-7 MPa and 220-260 ℃. The three reactions including methanol synthesis from CO and H2, CO2 and H2, and methanol dehydration were chosen as the independent reactions. The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the model were obtained by using simplex method combined with genetic algorithm. The model is reliable according to statistical analysis and residual error analysis. The synergy effect of the reactions over the bifunctional catalyst was compared with the effect for methanol synthesis catalyst under the same conditions based on the model. The effects of syngas containing N2 on the reactions were also simulated.

  16. Numerical investigation on the effect of injection pressure on the internal flow characteristics for diethyl ether, dimethyl ether and diesel fuel injectors using CFD

    Directory of Open Access Journals (Sweden)

    Vijayakumar Thulasi

    2011-01-01

    Full Text Available The spray characteristics of the diesel fuel are greatly affected by the cavitation formed inside the injector due to the high pressure differential across the nozzle. Many researchers across the globe are exploring the potential of using diethyl ether and dimethyl ether as an alternate for diesel fuel to meet the strict emission norms. Due to the variation in the fuel properties the internal flow characteristics in injectors for ether fuels are expected to be different from that of the diesel fuel. In this paper computational technique is used to study and compare the internal flow characteristics of diethyl ether, dimethyl ether and diesel fuel. The two phase flow model considering the fuel as a mixture of liquid and vapor is adopted for the simulation study. The injection pressure is varied from 100 to 400 bar and the flow characteristics of all three fuels are simulated and compared. Results indicate that all three fuels have distinct cavitating patterns owing to different property values. The dimethyl ether is found to be more cavitating than diesel and diethyl ether fuels as expected. The mass of fuel injected are found to be decreasing for the ether fuels when compared with diesel fuel at all injection pressures.

  17. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUP (Ⅳ) SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT DIETHYLAMINO THIAALKYL GROUP AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuanyin; MENG Lingzhi; YIN Yihua; GENG Chengai

    1994-01-01

    The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether and diethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that this reaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinate with platinum compound, and the platinum complex is a new kind of catalyst for the hydrosilylation of olefins with triethoxysilane.

  18. Cross sections for electron collisions with dimethyl ether

    OpenAIRE

    Sugohara, RT; Homem, MGP; Iga, I; de Souza, GLC; MACHADO, LE; Ferraz, JR; dos Santos, AS; Brescansin, LM; Lucchese, RR; Lee, MT

    2013-01-01

    We report a joint theoretical-experimental investigation of electron collision with dimethyl ether (DME) in the low- and intermediate-energy ranges. Experimental absolute differential, integral, and momentum-transfer cross sections for elastic e(-)-DME scattering are reported in the 100-1000 eV energy range. Our measurements were performed using a crossed electron-beam-molecular-beam geometry. The angular distribution of the scattered electrons was converted to absolute cross section using th...

  19. EL2595 EtherCAT端子模块

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    全新的EtherCAT端子模块EL2595用作控制“LED镇流器”,可直接连接LED灯。端子模块宽度仅为12mm,集成了控制、调光和监测功能。它可以连接各种电压和电流范围的灯具,

  20. Study on Synergy Effect in Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    王志良; 刁杰; 王金福; 金涌

    2001-01-01

    Influence of reaction temperature, pressure and space velocity on the direct synthesis of dimethyl ether (DME) from syngas is studied in an isothermal fixed-bed reactor. The catalyst is a physical mixture of C30 copper-based methanol (MeOH) synthesis catalyst and ZSM-5 dehydration catalyst. The experimental results show that the chemical synergy between methanol synthesis reaction and methanol dehydration reaction is evident. The conversion of carbon monoxide is over 90%.