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631.
632.
Weijie Lin Lorenz T. Biegler Annette M. Jacobson 《Macromolecular theory and simulations》2011,20(2):146-165
A comprehensive kinetic model is developed for a semi‐interpenetrating polymer network (SIPN) process, which involves simultaneous crosslinking, grafting, and degradation. Computational expense has been reduced considerably through a new component decomposition strategy, where a continuous variable approximation and a fixed pivot technique are applied for modeling each component. The inter‐polymer formulation is then reconstructed by a statistical approach. Based on the kinetic parameters obtained from the literature and a series of experiments, the model provides consistent agreement for gel fraction, joint molecular weight distribution (MWD) and polymer composition predicted in the studied cases, showing promising capability for the SIPN industrial application as well as for other polymer composite systems.
633.
d'Alnoncourt RN Kolen'ko YV Schlogl R Trunschke A 《Combinatorial chemistry & high throughput screening》2012,15(2):161-169
Technically relevant partial oxidation reactions represent complex reaction networks. Establishing a kinetic model for a system of multiple consecutive and parallel reaction steps is a challenging goal. The synthesis of acrylic acid by oxidation of propane using MoVTeNb mixed oxide as catalyst is such a reaction network. In an on-going study, a 10- fold parallel reactor set-up is used to vary systematically reaction conditions in a broad range over a single, well-defined MoVTeNb oxide. Selectivity and product yield in a multidimensional parameter space can give insight into the reaction network. Apparent activation energies and reaction orders of propane are derived for several conditions. Optimum reaction conditions within the investigated parameter space are specified. The results presented within this contribution contain about 200 data points measured in steady states each corresponding to reaction conditions that differ in temperature, contact time, and propane feed concentration. The fact that this data was collected in less than two months shows clearly the advantage of parallel screening of reaction conditions for mechanistic studies. 相似文献
634.
Yu S Ahmadi S Sun C Adibi PT Chow W Pietzsch A Göthelid M 《The Journal of chemical physics》2012,136(15):154703
The d-orbital contribution from the transition metal centers of phthalocyanine brings difficulties to understand the role of the organic ligands and their molecular frontier orbitals when it adsorbs on oxide surfaces. Here we use zinc phthalocyanine (ZnPc)/TiO(2)(110) as a model system where the zinc d-orbitals are located deep below the organic orbitals leaving room for a detailed study of the interaction between the organic ligand and the substrate. A charge depletion from the highest occupied molecular orbital is observed, and a consequent shift of N1s and C1s to higher binding energy in photoelectron spectroscopy (PES). A detailed comparison of peak shifts in PES and near-edge X-ray absorption fine structure spectroscopy illustrates a slightly uneven charge distribution within the molecular plane and an inhomogeneous charge transfer screening between the center and periphery of the organic ligand: faster in the periphery and slower at the center, which is different from other metal phthalocyanine, e.g., FePc/TiO(2). Our results indicate that the metal center can substantially influence the electronic properties of the organic ligand at the interface by introducing an additional charge transfer channel to the inner molecular part. 相似文献
635.
Hans‐Friedrich Klein Annette Kuhn Prof. Dr. Norbert Kuhn Prof. Dr. Stefan Laufer Markus Ströbele 《无机化学与普通化学杂志》2012,638(11):1784-1786
Triphenylphosphine reacts with thionyl chloride to give [Ph3PCl]Cl, Ph3PO and Ph3PS the formation of the anions S(O)Cl and SCl being discussed; the crystal structure of [Ph3PCl]Cl · S(O)Cl2 is reported. 相似文献
636.
637.
Annette Hille‐Rehfeld 《Chemie in Unserer Zeit》2010,44(4):243-243
638.
Uwe Klingebiel Mathias Noltemeyer Annette Wand 《Journal of organometallic chemistry》2006,691(12):2657-2665
Lithium salts of 2.6-dialkylanilines react with di-tert-butylfluorosilanes to give mono (1-3) - and bis (7, 8)-(2.6-dialkylphenylamino)silanes. Amino-2.6-dimethylphenyl-(di-tert-butylfluoro)silane (1) forms with BuLi a dimeric lithium salt (4) containing an eight-membered (LiFNSi)2 ring system. Thermally, 4 loses LiF and a bicyclic compound (9) via iminosilenes is obtained. The lithium salt of the bulkier amino-2.6-diisopropylphenyl-(di-tert-butylfluorosilanes) (5-7) thermally loses LiH and iminosilanes (10-12) with a 14π-system are isolated. The reaction mechanisms and crystal structures are discussed. 相似文献
639.
Goede K Grundmann M Holland-Nell K Beck-Sickinger AG 《Langmuir : the ACS journal of surfaces and colloids》2006,22(19):8104-8108
Peptide adhesion on semiconductor surfaces is quantitatively investigated by atomic force microscopy. The selected peptides are shown to cluster at the surface, with the larger, higher, and softer clusters appearing on the surfaces with lower peptide adhesion. Average cluster diameters vary from 40 nm on GaAs (100) to 300 nm on Si (100). Direct adhesion of the peptides to the surface competes with forming molecular aggregates that offer an overall reduced surface contact. 相似文献
640.