- A novel sp3Al-based porous single-ion polymer electrolyte for lithium ion batteries
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We report synthesis of an Al-based porous gel single-ion polymer electrolyte, lithium poly (glutaric acid aluminate) (LiPGAA), using glutaric acid and lithium tetramethanolatoaluminate as the precursors. The three-dimensional network compound provides short lithium-ion transport pathways and allows organic solvents to be accommodated in the composite for rapid ion transport. The tetraalkoxyaluminate units in the material enable Li-ions to be weakly associated with the polymeric framework, leading to a high ionic conductivity of 1.47 × 10-4 S cm-1 at room temperature and a high Li-ion transference number of 0.8. A membrane of the polymer was prepared via a solution cast method with PVDF-HFP poly(vinylidene-fluoride-co-hexafluoropropene) followed by soaking in a solution of ethylene carbonate (EC) and propylene carbonate (PC) (v/v, 1:1). A Li-ion battery assembled with the composite membrane displays remarkable cyclability with nearly 100% coulombic efficiency over a wide temperature range.
- Xu, Guodong,Rohan, Rupesh,Li, Jing,Cheng, Hansong
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- Partition coefficients of ketones, phenols, aliphatic and aromatic acids, and esters in n-hexane/nitromethane
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Liquid-liquid partition is used in sample preparation and in countercurrent and liquid-liquid chromatographic separations. Partition coefficients are widely used in toxicology, environmental, and analytical chemistry. The K hn determination procedure for the n-hexane/ nitromethane system was optimized and partition coefficients for 99 ketones, esters and trimethylsilyl derivatives of phenols, aliphatic and aromatic acids were determined. For 130 compounds, Khn values were predicted using mathematical relationships between Khn and other physicochemical and structural parameters. Versita Sp. z o.o.
- Kotowska, Urszula,Isidorov, Valery A.
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scheme or table
p. 813 - 824
(2012/03/27)
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- Process for the preparation of acyloxysilanes
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Process for the preparation of acyloxysilane comprising the step of reacting, in the presence of a strong acid, a hexahydrocarbyldisiloxane with a carboxylic anhydride.
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- Identification of products containing -COOH, -OH, and -C=O in atmospheric oxidation of hydrocarbons
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Atmospheric oxidation of hydrocarbons by hydroxyl radicals and ozone leads to products containing -COOH, -OH, and -C=O functional groups. The high polarity of such compounds precludes direct GC-MS analysis. In addition, many such compounds often exist in a single sample at trace levels. An analytical method has been developed to identify compounds containing one or more functional groups of carbonyl, carboxy, and hydroxy in atmospheric samples. In the method, -C=O groups are derivatized using O-(2,3,4,5,6- pentafluorobenzyl) hydroxy amine (PFBHA), and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)- trifluoroacetamide (BSTFA). The derivatives are easily resolved by a GC column. The chemical ionization mass spectra of these derivatives exhibit several pseudomolecular ions, allowing unambiguous determination of molecular weights. Functional group identification is accomplished by monitoring the ions in the electron ionization mass spectra that are characteristic of each functional group derivative: m/z 181 for carbonyl and m/z 73 and 75 for carboxyl and hydroxy groups. The method is used to identify products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene. Among products from ozone oxidation of α-pinene, we have detected pinonaldehyde, norpinonaldehyde, pinonic acid, norpinonic acid, C10 hydroxy dicarbonyls, pinic acid, 2,2-dimethyl-3-(formylmethyl)-cyclobutane-formic acid, and a product that has a molecular weight of 156 and contains a C=O and a COOH/OH group. The latter two products have not been reported previously. Δ3- Carene is structurally analogous to α-pinene in that both have an internal unsaturated bond where ozone oxidation takes place. We have also identified the corresponding analogous products, of which all but caronaldehyde are reported for the first time. An analytical method was developed to identify compounds containing one or more functional groups of carbonyl, carboxyl and hydroxyl in atmospheric samples. -C-to-O double bond groups are derivatized using 0-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine, and -COOH and -OH groups are derivatized using a silylation reagent N,O-bis(trimethylsilyl)-trifluoroacetamide. The derivatives are resolved using a gas chromatography column coupled with mass spectrometry. The method identified products in laboratory studies of ozone oxidation of α-pinene and Δ3-carene.
- Yu, Jianzhen,Flagan, Richard C.,Seinfeld, John H.
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p. 2357 - 2370
(2007/10/03)
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- PHOTOOXYGENATION OF 1,2-BIS(SILYLOXY)CYCLOALKENES
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The reaction of singlet oxygen with O-silylated cyclic enediols 1a, b afforded as ene products the hydroperoxy silyl enol ethers 3a,b and as cleavage products the silyl esters 4a,b; the latter presumably derived from rearrangement of the intermediary sily
- Adam, Waldemar,Wang, Xiaoheng
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p. 1245 - 1248
(2007/10/02)
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