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81.
82.
Thermodynamic modeling of the phase behavior of binary systems of ionic liquids and carbon dioxide with the group contribution equation of state 总被引:1,自引:0,他引:1
Breure B Bottini SB Witkamp GJ Peters CJ 《The journal of physical chemistry. B》2007,111(51):14265-14270
The group contribution equation of state (GC-EOS) was applied to predict the phase behavior of binary systems of ionic liquids of the homologous families 1-alkyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate with CO2. Pure group parameters for the new ionic liquid functional groups [-mim][PF6] and [-mim][BF4] and interaction parameters between these groups and the paraffin (CH3, CH2) and CO2 groups were estimated. The GC-EOS extended with the new parameters was applied to predict high-pressure phase equilibria in binary mixtures of the ionic liquids [emim][PF6], [bmim][PF6], [hmim][PF6], [bmim][BF4], [hmim][BF4], and [omim][BF4] with CO2. The agreement between experimental and predicted bubble point data for the ionic liquids was excellent for pressures up to 20 MPa, and even for pressures up to about 100 MPa, the agreement was good. The results show the capability of the GC-EOS to describe phase equilibria of systems consisting of ionic liquids. 相似文献
83.
The Use of Graphitic Carbon Nitride Based Composite Anodes for Lithium‐Ion Battery Applications 下载免费PDF全文
Thomas S. Miller Ana Belen Jorge Andrea Sella Furio Corà Paul R. Shearing Daniel J. L. Brett Paul F. McMillan 《Electroanalysis》2015,27(11):2614-2619
Graphitic carbon nitride (gCN) is shown to undergo lithium insertion reactions applicable with lithium‐ion battery anodes. Lithium capacity was found to be substantially lower than theoretically expected, so the properties of gCN composited with conducting graphite (CG), which was added to improve the performance, were investigated. The electrodes exhibited a systematic increase in lithium uptake with CG content, but the capacity never exceeded that of graphite. It is shown that electron transport via conducting pathways was limiting. Li+ uptake for 10 % gCN was similar to a graphite electrode, indicating that gCN does play a role in determining the storage capacity. 相似文献
84.
Chemical and Structural Stability of Zirconium‐based Metal–Organic Frameworks with Large Three‐Dimensional Pores by Linker Engineering 下载免费PDF全文
Dr. Suresh B. Kalidindi Dr. Sanjit Nayak Dr. Michael E. Briggs Dr. Susanna Jansat Dr. Alexandros P. Katsoulidis Dr. Gary J. Miller Dr. John E. Warren Dr. Dmytro Antypov Dr. Furio Corà Dr. Ben Slater Dr. Mark R. Prestly Dr. Carlos Martí‐Gastaldo Prof. Matthew J. Rosseinsky 《Angewandte Chemie (International ed. in English)》2015,54(1):221-226
The synthesis of metal–organic frameworks with large three‐dimensional channels that are permanently porous and chemically stable offers new opportunities in areas such as catalysis and separation. Two linkers (L1=4,4′,4′′,4′′′‐([1,1′‐biphenyl]‐3,3′,5,5′‐tetrayltetrakis(ethyne‐2,1‐diyl)) tetrabenzoic acid, L2=4,4′,4′′,4′′′‐(pyrene‐1,3,6,8‐tetrayltetrakis(ethyne‐2,1‐diyl))tetrabenzoic acid) were used that have equivalent connectivity and dimensions but quite distinct torsional flexibility. With these, a solid solution material, [Zr6O4(OH)4(L1)2.6(L2)0.4]?(solvent)x, was formed that has three‐dimensional crystalline permanent porosity with a surface area of over 4000 m2 g?1 that persists after immersion in water. These properties are not accessible for the isostructural phases made from the separate single linkers. 相似文献
85.
Chemoselective Alternating Copolymerization of Limonene Dioxide and Carbon Dioxide: A New Highly Functional Aliphatic Epoxy Polycarbonate 下载免费PDF全文
Chunliang Li Dr. Rafaël J. Sablong Prof. Dr. Cor E. Koning 《Angewandte Chemie (International ed. in English)》2016,55(38):11572-11576
The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2) catalyzed by a zinc β‐diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg) up to 135 °C. These polycarbonates can be efficiently modified by thiols or carboxylic acids in combination with lithium hydroxide or tetrabutylphosphonium bromide as catalysts, respectively, without destruction of the main chain. Moreover, polycarbonates bearing pendent cyclic carbonates can be quantitatively prepared by CO2 insertion catalyzed by lithium bromide. 相似文献
86.
Khalik M. Sabil Geert-Jan Witkamp Cor J. Peters 《The Journal of chemical thermodynamics》2010,42(1):8-16
In the present work, the three- and four-phase hydrate equilibria of (carbon dioxide (CO2) + tetrahydrofuran (THF) + water) system are measured by using Cailletet equipment in the temperature and pressure range of (272 to 292) K and (1.0 to 7.5) MPa, respectively, at different CO2 concentration. Throughout the study, the concentration of THF is kept constant at 5 mol% in the aqueous solution. In addition, the fluid phase transitions of LW–LV–V → LW–LV (bubble point) and LW–LV–V → LW–V (dew point) are determined when they are present in the ternary system. For comparison, the three-phase hydrate equilibria of binary (CO2 + H2O) are also measured. Experimental measurements show that the addition of THF as a hydrate promoter extends hydrate stability region by elevating the hydrate equilibrium temperature at a specified pressure. The three-phase equilibrium line H–LW–V is found to be independent of the overall concentration of CO2. Contradictory, at higher pressure, the phase equilibria of the systems are significantly influenced by the overall concentration of CO2 in the systems. A liquid–liquid phase split is observed at overall concentration of CO2 as low as 3 mol% at elevated pressure. The region is bounded by the bubble-points line (LW–LV–V → LW–LV), dew points line (LW–LV–V → LW + V) and the four-phase equilibrium line (H + LW + LV + V). At higher overall concentration of CO2 in the ternary system, experimental measurements show that pseudo-retrograde behaviour exists at pressure between (2.5 and 5) MPa at temperature of 290.8 K. 相似文献
87.
88.
89.
Rubin Huang Cor E. Koning John C. Chadwick 《Journal of polymer science. Part A, Polymer chemistry》2007,45(17):4054-4061
The effects of hydrogen in ethylene polymerization and oligomerization with different bis(imino)pyridyl iron(II) complexes immobilized on supports of type MgCl2/AlEtn(OEt)3–n have been investigated. Hydrogen has a significant activating effect on polymerization catalysts containing relatively bulky bis(imino)pyridyl ligands, but this is not the case in ethylene oligomerization with a catalyst containing relatively little steric bulk in the ligand. It was found that the presence of hydrogen in the latter system led to decreased activity and an overall increase rather than a decrease in product molecular weight, indicating deactivation of active species producing low molecular weight polymer and oligomer. Decreased formation of vinyl‐terminated oligomers in the presence of hydrogen can therefore contribute to the activating effect of hydrogen in ethylene polymerization with immobilized iron catalysts, if it is assumed that hydrogen activation is related to chain transfer after a 2,1‐insertion of a vinyl‐terminated oligomer into the growing polymer chain. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4054–4061, 2007 相似文献
90.
Rubin Huang Nileshkumar Kukalyekar Cor E. Koning John C. Chadwick 《Journal of molecular catalysis. A, Chemical》2006,260(1-2):135-143
Ethylene polymerizations carried out with various bis(imino)pyridyl iron, chromium and vanadium complexes immobilized on a MgCl2/AlRn(OEt)3−n support gave relatively broad polyethylene molecular weight distributions in the case of iron, but high molecular weight and a very narrow molecular weight distribution with vanadium, indicative of a single active species. The narrow MWD was confirmed by melt rheometry. Similar results were obtained after reaction of the bis(imino)pyridyl complex LVCl3 (6) with MeLi or AlEt3, where alkylation of the pyridine ring gives a complex L′VCl2 (7). In the case of chromium, a bimodal distribution was obtained, with evidence of incomplete catalyst immobilization. The polyethylene molecular weights obtained with the iron complexes were strongly dependent on the substituents in the bis(imino)pyridyl ligand, and were somewhat higher than have been obtained in homogeneous polymerization. In contrast, the molecular weights obtained with the bis(imino)pyridyl chromium and vanadium complexes were much higher that those previously obtained under homogeneous conditions. In all cases, the activities of the immobilized catalysts were higher than those found in homogeneous polymerization. 相似文献