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991.
992.
Niklas Paul Matthias Kraume Sebastian Schön Regine von Klitzing 《American Institute of Chemical Engineers》2015,61(3):1092-1104
In many industrial applications, the knowledge of the occurring transport processes in liquid/liquid systems is of great interest to design a multiphase reactor or an extraction column, for instance. All transport processes in liquid/liquid systems are governed by the interface. In some processes surfactants are needed. Surfactants change many interfacial properties which affect the transport processes. In this work, the influence of high surfactant concentrations (micellar systems) on transport processes is regarded. To understand, the occurring reduction of the drop rise velocity and of mass transfer rates experimental investigations of the occurring interfacial phenomena are carried out. Therefore, interfacial tension measurements as well as colloidal probe atomic force measurements of liquid/liquid systems were conducted. It was proved that for high nonionic surfactant concentrations a change of the phase behavior must be taken into consideration to describe transport processes in micellar liquid/liquid systems. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1092–1104, 2015 相似文献
993.
Degradation of Microcellular PLGA‐PEG Copolymer for Use in a Drug Delivery System for the Urinary Bladder
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994.
Natural rubber latex contains different allergenic proteins and peptides that restrict its application in consumer products. Small mineral particles have a comparatively high specific surface area and are therefore well suited to adsorb such biomolecules. The adsorption of such biomolecules onto different polymorphic phases of calcium carbonate, i.e., calcite, aragonite, and vaterite, was quantitatively determined, both from solution as well as from cured natural rubber latex. All phases were able to adsorb the allergens, with slight differences between the different allergens. Desorption experiments showed differences between the allergens of natural rubber latex, but only small differences between the polymorphic phases of calcium carbonate. The release of the allergens from latex objects with incorporated calcium carbonate particles showed that a retention of allergens is possible by adding calcium carbonate as a filler material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41271. 相似文献
995.
Synthese von aliphatischen Aldehyden aus Alkanen und Kohlendioxid: Valeraldehyd aus Butan und CO2 – Machbarkeit und Grenzen
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Susanne Fritschi Wolfgang Korth Jennifer Julis Daniela Kruse Hanna Hahn Robert Franke Ivana Fleischer Abhishek Dutta Chowdhury Nico Weding Ralf Jackstell Matthias Beller Andreas Jess 《化学,工程师,技术》2015,87(10):1313-1326
During the last decades, the engineering of chemical processes has focused more and more on energy efficiency and reduction of climate‐changing emissions. Regarding the synthesis of aldehydes, the photocatalytic dehydrogenation of alkanes to olefins, using visible (sun) light, and the subsequent hydroformylation of such olefins with CO2 seem to be capable to achieve both targets. This work deals mainly with catalyst concepts for both reaction steps. Here, kinetic studies of the photocatalytic alkane dehydrogenation are presented, and the feasibility of hydroformylation using CO2 is described in a continuous gas phase reaction. The problems that have to be solved befoe the technical application are discussed and an economic and ecological evaluation for both processes is carried out. 相似文献
996.
997.
Investigation of the migration behavior of polyisobutylene with various molecular weights in ethylene/α‐olefin copolymer blown stretch films for improved cling properties
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Mirko Rennert Steffen Fiedler Michael Nase Matthias Menzel Sandra Günther Jörg Kressler Wolfgang Grellmann 《应用聚合物科学杂志》2014,131(10)
High retention forces are the basic requirements on stretch films for agricultural or pallet wrapping of goods and significantly influenced by cling properties (autohesion) that are essential for a reliable load stability during transportation and storage. Low molecular weight polyisobutylene (PIB) has tacky properties and is immiscible with polyethylene. Blended with ethylene/α‐olefin copolymers in coextruded stretch films, PIB can migrate to the film surfaces and cause cling properties. Cling and adhesion forces were investigated using the mechanical cling test, atomic force, and scanning electron microscopy and infrared spectroscopy. The molecular weight of the PIB as well as density and crystallinity of the matrix material have strong influences on migration kinetics and therefore, on the cling forces. Cling forces increase with increasing aging time, having a maximum after 2 weeks of production. The following slight decrease of the cling force might be correlated with a beginning degradation process of the UV sensitive PIB. Polyisobutylene with higher molecular weight diffuses slower through a linear low density polyethylene (LLDPE) matrix than lower molecular weight PIB, but can cause higher cling forces on the film surfaces. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40239. 相似文献
998.
In the context of inline monitoring and controlling of forming processes, the distribution of acting forces on tool and forming machine causing elastic deformation of the clamping surfaces provides fundamental information on the resulting part quality whereas the inline detection is still challenging. This paper presents a novel method using the T-slot geometry as a cognitive area for inline analyzing of the elastic deformation of the tool-clamping surfaces. Using a newly developed sensor device, the elastic deformation state of the T-slot geometry under process forces is detected by strain measuring of a deformation body mounted inside the T-slot. The functionality principle of the sensor device and measuring method for process monitoring are demonstrated by simulation and experiments, demonstrating the potential for process control. 相似文献
999.
Anusuya Choudhury Anil K. Bhowmick Christopher Ong Matthias Soddemann 《Polymer Engineering and Science》2010,50(7):1389-1399
The present work derives a relationship between structure and properties of hydrogenated nitrile rubber (HNBR) in the presence as well as absence of nanofillers. Four different grades of HNBR were selected to examine the influence of polarity, unsaturation, and molecular weight on thermal, mechanical, and dynamic mechanical properties of the elastomers and particularly their nanocomposites. An increase in thermal stability, tensile strength, modulus at 100% elongation as well as storage modulus of the unfilled rubber was observed with increase in polarity (acrylonitrile content). Different nanofillers, such as montmorillonite, sepiolite, and nanosilica were used to improve the above properties of the unfilled rubber. Interestingly, a reverse trend of thermal properties was observed for the nanocomposites with acrylonitrile variation, although mechanical and dynamic mechanical properties exhibited similar trend to those of the unfilled rubber. These properties, however, gradually deteriorated as the level of unsaturation on the polymer backbone was increased. On addition of the nanofillers, it was found that the improvement in thermal and mechanical properties was higher for the elastomer having 5.5% diene content. The results were explained by X‐ray Diffraction, Atomic Force Microscopy, Energy Dispersive X‐ray mapping, and swelling studies. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers 相似文献
1000.
Jens Langer Helmar Görls Matthias Westerhausen 《Inorganic chemistry communications》2010,13(4):488-490
The reaction of 1,1-bis(diphenylphosphino)methane (dppm) and [py2Ni(C2H4COO)] with trace amounts of water leads to the formation of the novel pentanuclear organonickel compound [(μ2-dppm)2{Ni(C2H4COO)}4 * Ni(OH)2] (1) bearing nickel centres in square planar as well as in octahedral coordination sphere. In presence of NiBr2, the related trinuclear complex [(μ2-dppm){Ni(C2H4COO)}2 * NiOH(H2O)(py)2]+ Br? (2) was isolated and characterized by elemental analysis, IR measurements and X-ray single crystal structural analysis. These compounds are rare examples of organonickel compounds with μ3-hydroxide ligands and to best of our knowledge the first nickelacyclic carboxylates stabilized by such simple inorganic compounds as ligands. 相似文献