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Ceramic Support (ceramic + support)
Selected AbstractsNovel Method for Obtaining Corundum Layers of High Surface Area on Ceramic Supports for High-Temperature CatalysisJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2002Alejandro Souto The surface of an aluminosilicate ceramic was transformed to a corundum layer of high specific surface area by heating at 1300°,1450°C in a controlled reducing atmosphere. This procedure selectively reduced and volatilized the silica of the glass and mullite, and the alumina of the mullite formed a layer of corundum crystals with a thickness of ,20 ,m and a specific surface area of ,16 m2/g. Specific surface area remained stable at 10.5 m2/g after prolonged heating at 1300°C in air, and at 8.5 m2/g at 1450°C. These materials are well suited for use as catalyst supports in applications such as catalytic combustion at temperatures in this range. [source] Interfacial adhesion between polymer separation layer and ceramic support for composite membraneAICHE JOURNAL, Issue 6 2010Wang Wei Abstract An in situ characterization method for mechanical and adhesive properties of organic/ceramic composite membranes is built on the basis of nanoindentation technique in this work. The polydimethylsiloxane (PDMS) was used as the separation layer with the support of porous ZrO2/Al2O3 ceramic tubes. The effects of roughness of the ceramic support and the viscosity of PDMS solution on the mechanical properties of the PDMS separation layer and the interfacial adhesion at the interface were investigated in detail. It was found that when the roughness of the ceramic support increased and the viscosity of PDMS solution decreased, the interfacial adhesion strength of PDMS/ceramic composite membrane increased, but these two variables had little effect on the mechanical properties of the PDMS separation layer. Our results indicate that the mechanical interlocking dominates the adhesion between the PDMS separation layer and the porous ceramic support. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Water gas shift reaction via Pd-based membranesASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2009Silvano Tosti Abstract The water gas shift reaction has been studied in tubular Pd-based membranes: a thin walled dense tube and a composite Pd-ceramic tube have been considered. A computer code based on a finite element model has been developed for modelling the membrane reactor. The model accounts for the reaction kinetic, the hydrogen diffusion through the porous ceramic support and permeation through the PdAg membrane and for the partial pressure gradients of hydrogen generated at the permeate side of the membrane when a flow of purge gas is introduced. The code has been used to assess the influence of temperature, lumen pressure, presence of wall effects and sweep gas mode on the reaction conversion and hydrogen yield of the membrane reactors. At 200 kPa of lumen pressure and counter-current sweep mode, it was found that both reaction conversion and hydrogen yield increase with temperature: the dense and the composite membranes exhibit very close values of conversion (more than 99% at 400 °C) and hydrogen yield (96,97% at 400 °C). In co-current mode, the highest values of both reaction conversion and hydrogen yield have been assessed at 350 °C, while it was demonstrated that the beneficial effects of increasing the lumen pressure up to 400 kPa are maximum at 300 °C. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Streaming potential characterization of LBL membranes on porous ceramic supportsAICHE JOURNAL, Issue 4 2007Yiwei Chen Abstract An in-situ characterization of the growth of the self-assembled polyelectrolyte membranes on the porous support was conducted by applying transmembrane streaming potential measurement via surface charge monitoring. The membranes were prepared by layer-by-layer alternative deposition of poly (allylamine hydrochloride) and poly (styrenesulfonate) on porous ceramic supports. The surface charge variations of membranes as functions of different top-assembled materials and numbers of deposited cycles were investigated. Different top-assembled materials make isoelectric points of the as-prepared membranes drift in opposite directions and also lead to symmetrical signal changes of zeta-potential in salt solutions at the isoelectric points of the supports. Ex-situ characterizations, including scanning electron microscopy, atomic force microscopy, and energy dispersive X-ray spectroscopy, also confirm the alternative deposition of polyelectrolytes. It is demonstrated that the transmembrane streaming potential measurement is effective in studying the growth of layer-by-layer membranes on porous support. © 2007 American Institute of Chemical Engineers AIChE J, 2007 [source] | ||||||||||