Kinetic studies have been performed on the reactions of OH and NO(3) radicals and ozone with three ethyleneglycol vinyl ethers (EGVEs), that is, ethyleneglycol monovinyl ether (EGMVE, HOCH(2)CH(2)OCH=CH(2)), ethyleneglycol divinyl ether (EGDVE, H(2)C=CHOCH(2)CH(2)OCH=CH(2)), and diethyleneglycol divinyl ether (DEGDVE, H(2)C=CHOCH(2)CH(2)OCH(2)CH(2)OCH=CH(2)). Using a relative rate technique, rate coefficients have been determined for the reactions in a 405 L borosilicate glass chamber at (298 +/- 3) K in one atmosphere of synthetic air using in situ FTIR spectroscopy to monitor the reactants. The following rate coefficients (in units of cm(3) molecule(-1) s(-1)) were obtained: (1.04 +/- 0.22) x 10(-10), (1.23 +/- 0.33) x 10(-10), and (1.42 +/- 0.30) x 10(-10) for the reaction of OH with EGMVE, EGDVE, and DEGDVE, respectively; (2.23 +/- 0.46) x 10(-12), (1.95 +/- 0.50) x 10(-12), and (6.14 +/- 1.38) x 10(-12) for the reaction of NO(3) with EGMVE, EGDVE, and DEGDVE, respectively; and (2.02 +/- 0.41) x 10(-16), (1.69 +/- 0.41) x 10(-16), and (2.70 +/- 0.56) x 10(-16) for ozonolysis of EGMVE, EGDVE, and DEGDVE, respectively. Using the kinetic rate data, tropospheric lifetimes for EGMVE, EGDVE, and DEGDVE with respect to their reactions with OH, NO(3), and ozone have been estimated for typical ambient air concentrations of these oxidants.
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http://dx.doi.org/10.1021/jp809732u | DOI Listing |
Biomolecules
December 2024
Faculty of Chemical and Pharmaceutical Technologies and Biomedical Preparations, D. Mendeleev University of Chemical Technology of Russia, Miusskaya pl. 9, Moscow 125047, Russia.
The objective of this study was to compare the properties of core-shell nanoparticles with a PLGA core and shells composed of different types of polymers, focusing on their structural integrity. The core PLGA nanoparticles were prepared either through a high-pressure homogenization-solvent evaporation technique or nanoprecipitation, using poloxamer 188 (P188), a copolymer of divinyl ether with maleic anhydride (DIVEMA), and human serum albumin (HSA) as the shell-forming polymers. The shells were formed through adsorption, interfacial embedding, or conjugation.
View Article and Find Full Text PDFACS Omega
December 2024
Division of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.
A Hoveyda-Grubbs (HG)-type olefin metathesis complex with a selenoether moiety at the terminus of phenoxy moiety was synthesized. The complex showed direct selenium-atom coordination to the ruthenium center, resulting in higher thermodynamic stability compared with the parent HG catalyst. The selenium atom binding enhanced the tolerance to protic solvent molecules in ring-closing metathesis of -tosyldiallylamide and diethyl diallylmalonate, and also in the cross metathesis between 3-butenylbenzoate and methyl acrylate.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
December 2024
Department of Agricultural Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan.
Escherichia coli expressing SrPlsAR from Selenomonas ruminantium produces plasmalogen, comprising almost 60% of the total phospholipid content under anaerobic conditions. Both plasmenylethanolamine and plasmenylglycerol were detected, and the major acyl aldehyde derived from sn-1 vinyl ether was C16:1. Plasmalogen synthesis is affected by mutations in ATP-binding sites and Cys expected to be involved in the formation of the [4Fe-4S] cluster.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States.
Highly energetic boron (B) particles embedded in hydroxyl-terminated polybutadiene (HTPB) thermosetting polymers represent stable solid-state fuel. Laser-heating of levitated B/HTPB and pure HTPB particles in a controlled atmosphere revealed spontaneous ignition of B/HTPB in air, allowing for examination of the exclusive roles of boron. These ignition events are probed via simultaneous spectroscopic diagnostics: Raman and infrared spectroscopy, temporally resolved high-speed optical and infrared cameras, and ultraviolet-visible (UV-vis) spectroscopy.
View Article and Find Full Text PDFChem Sci
December 2024
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University Hangzhou 310027 China
Cationic polymerization of vinyl ethers to access poly(vinyl ether) polymeric materials has been challenging due to stringent polymerization conditions and inevitable chain transfer. Herein we introduce a protocol using trifluoromethyl sulfonates to catalyze the polymerization of a series of vinyl ethers. These trifluoromethyl sulfonates are fully commercially available and can be stored under ambient conditions.
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