Pore Structure Evolution of Lanthana–Alumina Systems Prepared through Coprecipitation (2000)
Nair, Jalajakumari, Nair, P., Mizukami, Fujio, Ommen Van, J.G., Doesburg, Giel B.M., Ross, J.R.H., ...
Pure Al2O3 and different compositions of La2O3–Al2O3 samples have been prepared through coprecipitation. Even after heating at 1300°C, the compositions La2O3·11Al2O3 and La2O3·13Al2O3 had higher...
Pore structure evolution of lanthana-alumina systems prepared through coprecipitation (2000)
Nair, J., Nair, P., Mizukami, F., Ommen, J.G. Van, Doesburg, E.B.M., Ross, J.R.H., ...
Structural aspects of the ionic conductivity of La1xSrxCoO3-d (2000)
The crystal structure of La1−xSrxCoO3−δ in the composition range 0≤x≤0.8 was investigated by means of powder XRD. A more detailed study was performed on the x=0.7 composition by neutron...
Sintering of Lanthanum Zirconate (1999)
Nair, Jalajakumari, Nair, P., Doesburg, Giel B.M., Ommen Van, J.G., Ross, J.R.H., Burggraaf, A.J., ...
Lanthanum zirconate (La2Zr2O7) was prepared by coprecipitating lanthanum nitrate and zirconyl oxychloride at pH 10, followed by ethanol washing. The initial high surface area of 304 m2·g−1...
Sintering of lanthanum zirconate (1999)
Kumari, J., Kumar, K.N.P., Doesburg, E.B.M., Ommen, J.G. Van, Ross, J.R.H., Burggraaf, A.J.
Theoretical expressions for single gas permeation are analysed and evaluated with selected literature and some new experimental data on Silicalite/ZSM-5 membranes. The phenomenological...
Theoretical expressions for single gas permeation are analysed and evaluated with selected literature and some new experimental data on Silicalite/ZSM-5 membranes. The phenomenological...
Nair, Jalajakumari, Nair, P., Ommen Van, J.G., Ross, J.R.H., Burggraaf, A.J., Mizukami, Fujio
Alkoxide-derived boehmite precipitates were subjected to different post-precipitation treatments to obtain a peptized sol, an unpeptized slurry, and an ethanol-washed gel precipitate. These materials...
Permeation of single gases in thin zeolite MFI membranes (1998)
Burggraaf, A.J., Keizer, K., Verweij, H.
The permeation of a series of gases with widely different Lennard-Jones kinetic diameters and sorption properties is investigated as a function of feed pressure (up to 100 kPa) and temperature...
Preparation and characterization of thin zeolite MFI membranes on porous supports (1998)
Keizer, K., Burggraaf, A.J., Verweij, H.
Thin (2¿7 ¿m) polycrystalline randomly-oriented zeolite MFI membranes were prepared on an ¿-Al2O3 support by one or more subsequent hydrothermal treatments. Different particle sizes (275¿700 nm)...
Kinetic decompositionof La0.3Sr0.7CoO3-d perovskite membranes during oxygen permeation (1998)
Bouwmeester, H.J.M., Burggraaf, A.J.
In this paper, a study is presented towards the stability of oxygen permeable membranes of perovskite La0.3Sr0.7CoO3¿¿ in an oxygen pressure gradient. It is shown that phase separation occurs at...
preparation of La0.3Sr0.7CoO3-d perovskite by thermal decomposition of metal-EDTA complexes (1998)
Kruidhof, H., Nijmeijer, A., Winnubst, A.J.A., Burggraaf, A.J.
Two component permeation through thin zeolite MFI membranes (1998)
Keizer, K., Burggraaf, A.J., Verweij, H.
Two component permeation measurements have been performed by the Wicke¿Kallenbach method on a thin (3 ¿m) zeolite MFI (Silicalite-1) membrane with molecules of different kinetic diameters, dk. The...
textural stability as a characterization tool of high temperature catalysts. (1998)
Kumari, J., Kumar, K.N.P., Doesburg, E.B.M., Ommen, J.G. Van, Burggraaf, A.J., Mizukami, F.
preparation and characterization of lanthanum zirconate (1998)
Kumari, J., Kumar, K.N.P., Doesburg, E.B.M., Ommen, J.G. Van, Ross, J.R.H., Burggraaf, A.J.
Permeation of single gases in thin zeolite MFI membranes (1998)
Burggraaf, A.J., Keizer, K., Verweij, H.
The permeation of a series of gases with widely different Lennard-Jones kinetic diameters and sorption properties is investigated as a function of feed pressure (up to 100 kPa) and temperature...
Preparation and characterization of thin zeolite MFI membranes on porous supports (1998)
Keizer, K., Burggraaf, A.J., Verweij, H.
Thin (2–7 μm) polycrystalline randomly-oriented zeolite MFI membranes were prepared on an -Al2O3 support by one or more subsequent hydrothermal treatments. Different particle sizes (275–700 nm)...
Kinetic decomposition of La0.3Sr0.7CoO3−δ perovskite membranes during oxygen permeation (1998)
Bouwmeester, H.J.M., Burggraaf, A.J.
In this paper, a study is presented towards the stability of oxygen permeable membranes of perovskite La0.3Sr0.7CoO3−δ in an oxygen pressure gradient. It is shown that phase separation occurs at...
Two component permeation through thin zeolite MFI membranes (1998)
Keizer, K., Burggraaf, A.J., Verweij, H.
Two component permeation measurements have been performed by the Wicke–Kallenbach method on a thin (3 μm) zeolite MFI (Silicalite-1) membrane with molecules of different kinetic diameters, dk. The...
Chen, C.S., Kruidhof, H., Bouwmeester, H.J.M., Verweij, H., Burggraaf, A.J.
Oxygen permeation measurements were performed on erbia-stabilized bismuth oxide-silver (40 v/o) composite membranes in the range of thickness of 1.60¿0.23 mm and temperature of 850¿650 °C. Air was...
Ionic conductivity of perovskite LaCoO3 measured by oxygen permeation technique (1997)
Chen, C.H., Kruidhof, H., Bouwmeester, H.J.M., Burggraaf, A.J.
Oxygen permeation measurement is demonstrated, not only for a mixed oxide ionic and electronic conductor, but also as a new alternative to determine ambipolar conductivities, which can be usually...
Effects of a second phase on the tribological properties of Al2O3 and ZrO2 ceramics (1997)
He, Y., Winnubst, A.J.A., Schipper, D.J., Burggraaf, A.J., Verweij, H.
The tribological properties of four different materials are investigated, tetragonal zirconia (Y-ZTP), Al2O3 dispersed in Y-TZP (ADZ), ZrO2 dispersed in Al2O3 (ZTA) and Al2O3 (with 300 ppm MgO)....
High-temperature catalyst supports and ceramic membranes: metastability and particle packing (1997)
Kumar, K.N.P., Mizukami, F., Okubo, T., Kumari, J., Keizer, K., Burggraaf, A.J.
Sliding wear of ZrO2-Al2O3 composite ceramics (1997)
He, Y., Winnubst, A.J.A., Burggraaf, A.J., Verweij, H., With, G. De
The friction and wear behaviour of two ZrO2-Al2O3 composite materials, ADZ (20 wt% Al2O3 dispersed in yttria-doped ZrO2 matrix) and ZTA (Al2O3-15 wt% ZrO2), were investigated. Sliding wear tests were...
Production of defect-poor nanostructured ceramics of yttria-zirconia (1997)
Sagel-Ransijn, C.D., Winnubst, A.J.A., Kerkwijk, B., Burggraaf, A.J., Verweij, H.
For the production of nanostructured ceramics of yttria-zirconia four powders differing in agglomerate strength, agglomerate size and crystallite size are compared. An ultra-fine-grained ceramic with...
Plasticity of nanocrystalline zirconia ceramics and composites (1997)
Winnubst, A.J.A., Boutz, M.M.R., He, Y., Burggraaf, A.J., Verweij, H.
The deformation strain rate of nanocrystalline Y-TZP shows an increase by a factor 4 if the grain size decreases from 200 to 100 nm. Real superplastic deformation (strain rate > 10¿4 s¿1) is...
Oxygen permeatin of La0.3Sr0.7CoO3-d (1997)
Chen, C.H., Bouwmeester, H.J.M., Doorn, E.A. Van, Kruidhof, H., Burggraaf, A.J.
The oxygen permeability of dense La0.3Sr0.7CoO3¿¿ membranes has been measured in the range 750¿1100°C under various oxygen partial pressure gradients. A sweep gas method was employed. Results...
Chen, C.S., Kruidhof, H., Bouwmeester, H.J.M., Verweij, H., Burggraaf, A.J.
Oxygen permeation measurements were performed on erbia-stabilized bismuth oxide-silver (40 v/o) composite membranes in the range of thickness of 1.60–0.23 mm and temperature of 850–650 °C. Air...
Ionic conductivity of perovskite LaCoO3 measured by oxygen permeation technique (1997)
Chen, C.H., Kruidhof, H., Bouwmeester, H.J.M., Burggraaf, A.J.
Oxygen permeation measurement is demonstrated, not only for a mixed oxide ionic and electronic conductor, but also as a new alternative to determine ambipolar conductivities, which can be usually...
Effects of a second phase on the tribological properties of Al2O3 and ZrO2 ceramics (1997)
He, Y.J., Winnubst, A.J.A., Schipper, D.J., Burggraaf, A.J., Verweij, H.
The tribological properties of four different materials are investigated, tetragonal zirconia (Y-ZTP), Al2O3 dispersed in Y-TZP (ADZ), ZrO2 dispersed in Al2O3 (ZTA) and Al2O3 (with 300 ppm MgO)....
Sliding wear of ZrO2-Al2O3 composite ceramics (1997)
He, Y.J., Winnubst, A.J.A., Burggraaf, A.J., Verweij, H., With De, G.
The friction and wear behaviour of two ZrO2-Al2O3 composite materials, ADZ (20 wt% Al2O3 dispersed in yttria-doped ZrO2 matrix) and ZTA (Al2O3-15 wt% ZrO2), were investigated. Sliding wear tests were...
Grain growth in ultrafine-grained Y-TZP ceramics (1997)
Sagel-Ransijn, C.D., Winnubst, A.J.A., Burggraaf, A.J., Verweij, H.
Grain growth in dense ultrafine-grained (120–600 nm) tetragonal ZrO2-Y2O3 ceramics is studied as a function of temperature. At all temperatures investigated both segregation and phase partitioning...
Production of defect-poor nanostructured ceramics of yttria-zirconia (1997)
Sagel-Ransijn, C.D., Winnubst, A.J.A., Kerkwijk, B., Burggraaf, A.J., Verweij, H.
For the production of nanostructured ceramics of yttria-zirconia four powders differing in agglomerate strength, agglomerate size and crystallite size are compared. An ultra-fine-grained ceramic with...
Plasticity of nanocrystalline zirconia ceramics and composites (1997)
Winnubst, A.J.A., Boutz, M.M.R., He, Y.J., Burggraaf, A.J., Verweij, H.
The deformation strain rate of nanocrystalline Y-TZP shows an increase by a factor 4 if the grain size decreases from 200 to 100 nm. Real superplastic deformation (strain rate > 10−4 s−1) is...
Oxygen permeatin of La0.3Sr0.7CoO3-d (1997)
Chen, C.H., Bouwmeester, H.J.M., Doorn Van, E.A., Kruidhof, H., Burggraaf, A.J.
The oxygen permeability of dense La0.3Sr0.7CoO3−δ membranes has been measured in the range 750–1100°C under various oxygen partial pressure gradients. A sweep gas method was employed. Results...
Brinkman, H.W., Meijerink, J., Vries, K.J. De, Burggraaf, A.J.
By means of electrochemical vapour deposition (EVD), it is possible to grow thin (0.5¿5 ¿m), dense zirconia/yttria layers on porous ceramic substrates. Kinetics of the EVD process, morphology and...
He, Y., Winnubst, A.J.A., Sagel-Ransijn, C.D., Burggraaf, A.J., Verweij, H.
The mechanical properties of ceramics with the compositions of 5 mol% YO1.5-TZP (ZY5) and 4 mol% YO1.5-4 mol% CeO2-TZP (ZY4Ce4) were investigated. Nanocrystalline powders of both TZPs were...
Transport properties of alkanes through ceramic thin zeolite MFI membranes (1996)
Keizer, K., Gilde, M.J., Verweij, H., Burggraaf, A.J.
Polycrystalline randomly oriented defect free zeolite layers on porous ¿-Al2O3 supports are prepared with a thickness of less than 5 ¿m by in situ crystallisation of silicalite-1. The flux of...
Hekkink, J.H.A., Keizer, K., Burggraaf, A.J.
Dried and calcined non-supported membrane top-layers of SiO2, SiO2/TiO2, SiO2/ZrO2 (10, 20 and 30 mol% TiO2 and ZrO2, respectively) and SiO2/Al2O3 (10 mol% AlO1.5) were prepared using acid catalyzed...
Oxygen permeation through oxygen ion oxide-noble metal dual phase composites (1996)
Chen, C.S., Kruidhof, H., Bouwmeester, H.J.M., Verweij, H., Burggraaf, A.J.
Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were...
Nair, B.N., Keizer, K., Elferink, J.W., Gilde, M.J., Verweij, H., Burggraaf, A.J.
Microporous silica membranes are known to exhibit molecular sieving effects. However, separation of nearly equal sized molecules is difficult to carry out by size exclusion. Introducing sorption...
Preparation of gas-tight strontium-doped lanthanum cobaltate by an aqueous sol-gel process (1996)
Chen, C.H., Kruidhof, H., Bouwmeester, H.J.M., Burggraaf, A.J.
Gas-tight dense membranes of highly Sr-doped LaCoO3 (such as the composition La0.3Sr0.7CoO3 chosen in this study) are difficult to prepare using usual synthesis processes. This report presents an...
Sagel-Ransijn, C.D., Winnubst, A.J.A., Burggraaf, A.J., Verweij, H.
A zirconia-yttria gel, made by coprecipitation, was treated in six different ways to obtain a nanocrystalline Y-TZP powder: one large gel batch was split into six parts of which one was crystallized...
Brinkman, H.W., Meijerink, J., Vries De, K.J., Burggraaf, A.J.
By means of electrochemical vapour deposition (EVD), it is possible to grow thin (0.5¿5 ¿m), dense zirconia/yttria layers on porous ceramic substrates. Kinetics of the EVD process, morphology and...
He, Y.J., Winnubst, A.J.A., Sagel-Ransijn, C.D., Burggraaf, A.J., Verweij, H.
The mechanical properties of ceramics with the compositions of 5 mol% YO1.5-TZP (ZY5) and 4 mol% YO1.5-4 mol% CeO2-TZP (ZY4Ce4) were investigated. Nanocrystalline powders of both TZPs were...
Transport properties of alkanes through ceramic thin zeolite MFI membranes (1996)
Keizer, K., Gilde, M.J., Verweij, H., Burggraaf, A.J.
Polycrystalline randomly oriented defect free zeolite layers on porous -Al2O3 supports are prepared with a thickness of less than 5 μm by in situ crystallisation of silicalite-1. The flux of alkanes...
Hekkink, J.H.A., Keizer, K., Burggraaf, A.J.
Dried and calcined non-supported membrane top-layers of SiO2, SiO2/TiO2, SiO2/ZrO2 (10, 20 and 30 mol% TiO2 and ZrO2, respectively) and SiO2/Al2O3 (10 mol% AlO1.5) were prepared using acid catalyzed...
Oxygen permeation through oxygen ion oxide-noble metal dual phase composites (1996)
Chen, C.S., Kruidhof, H., Bouwmeester, H.J.M., Verweij, H., Burggraaf, A.J.
Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were...
Preparation of gas-tight strontium-doped lanthanum cobaltate by an aqueous sol-gel process (1996)
Chen, C.H., Kruidhof, H., Bouwmeester, H.J.M., Burggraaf, A.J.
Gas-tight dense membranes of highly Sr-doped LaCoO3 (such as the composition La0.3Sr0.7CoO3 chosen in this study) are difficult to prepare using usual synthesis processes. This report presents an...
Sagel-Ransijn, C.D., Winnubst, A.J.A., Burggraaf, A.J., Verweij, H.
A zirconia-yttria gel, made by coprecipitation, was treated in six different ways to obtain a nanocrystalline Y-TZP powder: one large gel batch was split into six parts of which one was crystallized...
Oxygen permeation through dense oxide membranes (1995)
Bouwmeester, H.J.M., Brinkman, H.W., Doorn, A.R. Van, Kruidhof, H., Burggraaf, A.J.
Thermal and chemical stability of classical and modified mesoporous membranes (1995)
Zuter, J.M., Boer, W., Keizer, K., Verweij, H., Burggraaf, A.J.