Preparation and Characterization of Ultrathin Sol-gel Derived Membranes for Gas Separation Applications PDF Download

Author: Rakesh Sehgal
Publisher:
ISBN:
Category : Gas separation membranes
Languages : en
Pages : 272

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Author: Martin Johannes Wolf
Publisher:
ISBN: 9789036537926
Category :
Languages : en
Pages : 126

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Author: Neelesh J. Rane
Publisher:
ISBN:
Category :
Languages : en
Pages :

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CeO2, has numerous applications in industry including catalysts, electrolytes and in superconductors. One of the major area in which CeO2 research is lacking is in mesoporous inorganic membranes. The use of inorganic instead of organic membranes is advantageous if one is dealing with high temperatures, aggressive mixtures (chemical, mechanical, microbiological), high pressures (no compaction of inorganic membranes) or separation circumstances which make frequent cleaning of the membrane necessary. In addition to the ultrafiltration and gas separations, ceria is also most attractive as support for ultrathin dense ceramic or metallic membranes because of its thermal expansion coefficient, which match more closely with that of some dense membrane materials. Few researchers tried to prepare supported ceria membranes by the sol gel method. However they were unsuccessful to coat ceria layer directly on the support. So they coated ceria on top of alpha-alumina layer making a multilayer system. The ceria coating obtained had a very low surface area and consisted of some pinholes and cracks. Membranes with a narrow pore size distribution, in which especially large pores should be absent, are necessary to obtain a high degree of separation of mixtures. The present work is an attempt to prepare crack free and pinhole free supported and unsupported mesoporous ceria membranes by the sol gel method. A systematic study on microstructure and chemical evolution of ceria sols was done and the best available sol, which can give required ceria film thickness, was used for membrane preparation. Factors such as solid concentration, surface area and the organic impurities in the sols were considered. Ceria sol derived from cerium (IV) nitrate precursor having solid concentration of 172 g/L of CeO2 and whose particles showed a surface area of 101 m2/g was selected for fabrication of porous ceria membranes. Ceria was coated on chemically treated alpha-alumina support by dip-coating method. The pore structure and permeability properties of the supported membrane were studied by helium permeation experiments. SEM image shows ceria top-layer of thickness 28micron with an average pore diameter of 6.42 nm obtained by single dip coating of the ceria sol on the alumina support. XRD data reveal the fluorite type structure of ceria membranes. The permeability of ceria membrane is however low inspite of its high porosity, because of the thick top-layer obtained by the single dip-coating of ceria sol. The ionic conductivity of the ceria membranes is 0.06 - 8.5 S/cm in the temperature range of 600 - 900oC. These properties were compared with those of yttria-stabilized-zirconia (YSZ) membranes reported in the literature.

Author: David Levy
Publisher: John Wiley & Sons
ISBN: 352767084X
Category : Technology & Engineering
Languages : en
Pages : 1616

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This comprehensive three-volume handbook brings together a review of the current state together with the latest developments in sol-gel technology to put forward new ideas. The first volume, dedicated to synthesis and shaping, gives an in-depth overview of the wet-chemical processes that constitute the core of the sol-gel method and presents the various pathways for the successful synthesis of inorganic and hybrid organic-inorganic materials, bio- and bio-inspired materials, powders, particles and fibers as well as sol-gel derived thin films, coatings and surfaces. The second volume deals with the mechanical, optical, electrical and magnetic properties of sol-gel derived materials and the methods for their characterization such as diffraction methods and nuclear magnetic resonance, infrared and Raman spectroscopies. The third volume concentrates on the various applications in the fields of membrane science, catalysis, energy research, biomaterials science, biomedicine, photonics and electronics.

Author: Sumio Sakka
Publisher: Springer Science & Business Media
ISBN: 9781402079665
Category : Science
Languages : en
Pages : 716

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Since Dr. Disiich of Germany prepared a glass lens by the sol-gel method around 1970, sol-gel science and technology has continued to develop. Since then this field has seen remarkable technical developments as well as a broadening of the applications of sol-gel science and technology. There is a growing need for a comprehensive reference that treats both the fundamentals and the applications, and this is the aim of "Handbook of Sol-Gel Science and Technology."The primary purpose of sol-gel science and technology is to produce materials, active and non-active including optical, electronic, chemical, sensor, bio- and structural materials. This means that sol-gel science and technology is related to all kinds of manufacturing industries. Thus Volume 1, "Sol-Gel Processing," is devoted to general aspects of processing. Newly developed materials such as organic-inorganic hybrids, photonic crystals, ferroelectric coatings, photocatalysts will be covered. Topics in this volume include: Volume 2, "Characterization of Sol-Gel Materials and Products, "highlights the important fact that useful materials are only produced when characterization is tied to processing. Furthermore, characterization is essential to the understanding of nanostructured materials, and sol-gel technology is a most important technology in this new field. Since nanomaterials display their functional property based on their nano- and micro-structure, "characterization" is very important. Topics found in Volume 2 include: Sol-gel technology is a versatile technology, making it possible to produce a wide variety of materials and to provide existing substances with novel properties. This technology was applied to producingnovel materials, for example organic-inorganic hybrids, which are quite difficult to make by other fabricating techniques, and it was also applied to producing materials based on high temperature superconducting oxides. "Applications of Sol-Gel Technology," (Volume 3), will cover applications such as:

Author: Lisa Klein
Publisher: Springer Nature
ISBN: 3319321013
Category : Technology & Engineering
Languages : en
Pages : 3755

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Book Description
This completely updated and expanded second edition stands as a comprehensive knowledgebase on both the fundamentals and applications of this important materials processing method. The diverse, international team of contributing authors of this reference clarify in extensive detail properties and applications of sol-gel science and technology as it pertains to the production of substances, active and non-active, including optical, electronic, chemical, sensor, bio- and structural materials. Essential to a wide range of manufacturing industries, the compilation divides into the three complementary sections: Sol-Gel Processing, devoted to general aspects of processing and recently developed materials such as organic-inorganic hybrids, photonic crystals, ferroelectric coatings, and photocatalysts; Characterization of Sol-Gel Materials and Products, presenting contributions that highlight the notion that useful materials are only produced when characterization is tied to processing, such as determination of structure by NMR, in-situ characterization of the sol-gel reaction process, determination of microstructure of oxide gels, characterization of porous structure of gels by the surface measurements, and characterization of organic-inorganic hybrid; and Applications of Sol-Gel Technology, covering applications such as the sol-gel method used in processing of bulk silica glasses, bulk porous gels prepared by sol-gel method, application of sol-gel method to fabrication of glass and ceramic fibers, reflective and antireflective coating films, application of sol-gel method to formation of photocatalytic coating films, and application of sol-gel method to bioactive coating films. The comprehensive scope and integrated treatment of topics make this reference volume ideal for R&D scientists and engineers across a wide range of disciplines and professional interests.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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We prepared silica membranes using sol-gel techniques and explored the effects of postdeposition sintering, capillary stresses developed during drying, and surface derivatization of the membranes with titanium iso-propoxide. We observed that both partial sintering of membranes and development of larger-capillary stresses during membrane formation lead to consolidation of the membrane structure as evidenced by increased ideal separation factors, e.g.[alpha]CO[sub 2]2/CH[sub 4]> 250 over the temperature range of 160 to 220 C. Surface derivatization was also shown to be an effective tool to reduce the membrane pore size in an angstrom by angstrom fashion, resulting in comparable separation factors. What's more, the altered pore surface chemistry of TiO[sub 2] derivatized membranes may lead to improved stability and impart catalytic properties to the membrane surface.

Author: Y.A. Attia
Publisher: Springer Science & Business Media
ISBN: 1461525705
Category : Science
Languages : en
Pages : 380

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During my professional career, I developed a strong interest in sol-gel technology, and worked on both xerogel and aerogel systems. My fascination with aerogels has driven me to explore their commercial potential, which is currently an important component of my company's business plan. Together with my co-workers, I have also worked on the preparation of controlled PZT and silica xerogels as well as thin film coatings of metals by the sol-gel technology, These experiences convinced me of the tremendous potentials of this technology. A conviction that is shared by many scientists, engineers, and business leaders around the globe. Many sol-gel derived products are already articles of commerce. However, to expand the commercial potential of sol-gel technology, two challenges must be met: (1) the quality of sol-gel derived products must continue to meet or exceed the quality of competing products, (2) the production cost of sol-gel products (specially aerogels) must continued to decline. A key to lowering the costs of sol-gel products is finding inexpensive precursors.

Author: David Levy
Publisher: John Wiley & Sons
ISBN: 3527334866
Category : Technology & Engineering
Languages : en
Pages : 1604

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Book Description
This comprehensive three-volume handbook brings together a review of the current state together with the latest developments in sol-gel technology to put forward new ideas. The first volume, dedicated to synthesis and shaping, gives an in-depth overview of the wet-chemical processes that constitute the core of the sol-gel method and presents the various pathways for the successful synthesis of inorganic and hybrid organic-inorganic materials, bio- and bio-inspired materials, powders, particles and fibers as well as sol-gel derived thin films, coatings and surfaces. The second volume deals with the mechanical, optical, electrical and magnetic properties of sol-gel derived materials and the methods for their characterization such as diffraction methods and nuclear magnetic resonance, infrared and Raman spectroscopies. The third volume concentrates on the various applications in the fields of membrane science, catalysis, energy research, biomaterials science, biomedicine, photonics and electronics.

Author: Gülnihal Yelken
Publisher:
ISBN:
Category :
Languages : tr
Pages : 143

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