Nano/subnano-tuning of porous ceramic membranes for molecular separation

Tsuru, Toshinori

doi:10.1007/s10971-008-1712-5

Cited by 142 publications

(84 citation statements)

References 38 publications

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“…Partial hydrolysis with a less than stoichiometric amount of water is the primary necessity for the formation of less developed nanoscale polymeric sol structures. Sol-gel process is one of the most appropriate methods for the preparation of porous inorganic membranes with a wide range of controlled pore structures for different applications [1]. A microporous structure can only be obtained by the interpenetration of low branched polymeric species [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…The macroporous ceramic supports are expected to mechanically hold the thin separative layer and also be chemically inert. The generally used composite asymmetric ceramic membrane structure consists of several layers with a gradual decrease in pore size and thickness on a macroporous support to minimize the resistance to gas transport through the membrane [1]. Although dry pressing and extrusion are conventional techniques for the preparation of ceramic membrane supports, macroporous supports with excellent surface homogeneity and properties have been prepared through colloidal processing (slip casting/filtration) of stable dispersions without strong agglomerates [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Sol–gel derived mesoporous and microporous alumina membranes

Topuz

Çiftçioğlu

2010

J Sol-Gel Sci Technol

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Stable polymeric and colloidal boehmite sols were prepared by sol-gel process through controlled hydrolysis/condensation reactions. The particle sizes of the colloidal sols were in the 12-25 nm range depending on the process parameters and about 2 nm for polymeric sols. The presence of a significant increase in the microporosity content of the heat treated polymeric membranes relative to the mesoporous colloidal membranes might make the design of thermally stable microporous alumina membranes with controlled pore structures possible. The phase structure evolution in the 600-800°C range had shown that the crystallization of the gamma alumina in the amorphous matrix starts at about 800°C. This indicated that the pore structure stability may be enhanced through processing up to this relatively high temperature in polymeric alumina derived unsupported membranes. The permeance values of the two and three layered colloidal alumina membranes were observed to be independent of pressure which implies that the dominant gas transport mechanism is Knudsen diffusion in these structures. This was also supported by the 2.8 nm BJH pore sizes of the colloidal membranes. The Knudsen diffusion equation derived permeances of the polymeric alumina membranes with thicknesses of about 300 nm were determined to be very close to the experimentally determined permeance values.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Sol–gel derived mesoporous and microporous alumina membranes

Topuz

Çiftçioğlu

2010

J Sol-Gel Sci Technol

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“…These membranes are either prepared by a chemical vapor deposition (CVD) technique [6,7] or by using sol-gel methods [8][9][10]. Although silica membranes, fabricated by sol-gel methods, show great promise in gas separation, the technical challenges such as hydrothermal stability are still a point of concern [11]. Hybrid organosilica (e.g., bis-triethoxysilylethane: BTESE) membranes are very suitable to overcome such problems, since they show an improved hydrothermal stability [12,13].…”

Section: Introductionmentioning

confidence: 99%

“…The presence of hydrocarbon chains in the silica backbone improves the hydrothermal stability of such a hybrid silica matrix, however, at the cost of reduced gas selectivity [11]. A possible approach to improve the gas permselectivity of these hybrid silica membranes is the incorporation of metal ions in the hybrid silica matrix.…”

Section: Introductionmentioning

confidence: 99%

Doped microporous hybrid silica membranes for gas separation

Qureshi

Besselink

Elshof

et al. 2015

J Sol-Gel Sci Technol

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Hybrid silica (i.e., bis-triethoxysilylethane: BTESE) membranes doped with B, Ta or Nb were made through a sol-gel process. Triethyl borate, tantalum (V) ethoxide (TPE) and niobium (V) ethoxide (NPE) were selected as doping precursors. The doping concentration was optimized to produce sols, suitable for membrane fabrication. Thermal stability, structural analysis, crosssectional micrographs and single gas permeation experiments were performed on these membranes, and results are compared with an undoped BTESE membrane. It was observed that the synthesized doped BTESE materials and membranes resulted into a more open (and, in one occurrence, SF 6 permeable) pore microstructure, showing high permeances of larger gas molecules, while having a crosssectional thickness comparable to undoped BTESE membranes. Graphical Abstract& Louis Winnubst a.j.a.winnubst@utwente.nl;

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“…Recently high-flux inorganic membranes with good thermal and chemical stability have been developed for the separation of volatile molecular mixtures [6,7]. However, such inorganic membrane cannot be applied to the medical fields.…”

Section: Introductionmentioning

confidence: 99%