Synthesis of Porous Zirconia Spheres—Mechanism and Prospects for Multistep Processing

Sathyagal, Arun; Carr, Peter W.; McCormick, Alon V.

doi:10.1006/jcis.1999.6447

Cited by 5 publications

(4 citation statements)

References 9 publications

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“…27−29 McCormick et al first prepared porous zirconia spheres using the PICA process and also combined the PICA process with an oil emulsion method to obtain hierarchically structured spherical particles. 22 However, the as-prepared porous zirconia microspheres had wide size distribution. Tsung et al combined the acetic acid mediated sol−gel chemistry with the aerosol-assisted self-assembly approach to fabricate mesoporous zirconia submicrospheres with highly crystallized framework.…”

Section: Introductionmentioning

confidence: 99%

“…Porous zirconia microspheres have been fabricated by a few groups based on the polymerization-induced colloid aggregation (PICA) process, − oil emulsion method, solvothermal process, aerosol-assisted self-assembly approach, , and templating method. − McCormick et al first prepared porous zirconia spheres using the PICA process and also combined the PICA process with an oil emulsion method to obtain hierarchically structured spherical particles . However, the as-prepared porous zirconia microspheres had wide size distribution.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication of Monodisperse Porous Zirconia Microspheres and Their Phosphorylation for Friedel–Crafts Alkylation of Indoles

Chen

Ren

et al. 2014

ACS Appl. Mater. Interfaces

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Monodisperse porous zirconia (ZrO2) microspheres with nanocrystallized framework were fabricated by impregnation of porous polymer microspheres as a novel hard template with zirconia precursors followed by calcination to remove the template. Porous phosphorylated zirconia (PhZr) microspheres were prepared by further treating porous zirconia microspheres with phosphoric acid. The morphology, structure, and properties of these microspheres were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption measurement, FT-IR, and X-ray powder diffraction. The as-prepared zirconia and phosphorylated zirconia microspheres showed uniform particle size and well-defined morphology. The phosphorylated zirconia microspheres served as highly active solid acid catalysts for Friedel-Crafts alkylation of indoles with chalcones and could be reused for 22 cycles with negligible loss of activity. In situ pyridine-adsorbed FT-IR analysis of the best performing PhZr microspheres suggested the presence of both Lewis and Brønsted acid sites, and the total acidity as measured by temperature-programmed desorption of ammonia (NH3-TPD) was 328 μmol·g(-1).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fabrication of Monodisperse Porous Zirconia Microspheres and Their Phosphorylation for Friedel–Crafts Alkylation of Indoles

Chen

Ren

et al. 2014

ACS Appl. Mater. Interfaces

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“…One series of papers [135,147,[155][156][157][158][159][160][161][162][163] affords a comparison of the type of pore structure, sintering behavior, diffusion behavior, and chromatographic performance of mesoporous zirconia made of the same colloid through two different methods to make spherical aggregates-that using an oil emulsion (cf. [13]) versus that using polymerization method (cf.…”

Section: Effect Of Synthesis Methods On the Pore Structurementioning

confidence: 99%

“…Carr et al [17,135,147,[155][156][157][158][159][160][161][162][163] took an approach related to Iler's to make monodisperse, micron-scale spherical microparticles out of commercially available colloid through the addition of urea and formaldehyde. Pore structure and particle size variations were investigated as preparation and sintering conditions were manipulated, and the most striking result was that very strong, very porous (up to 50% porous), very large pore (200 Å minimum aperture) monodisperse spherical particles could be made.…”

Section: Zirconiamentioning

confidence: 99%

Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC

Nawrocki

Dunlap

McCormick

et al. 2004

Journal of Chromatography A

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316

187

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The first part of the review contrasts the main drawbacks of silica-based packings such as their relative thermal and chemical instability with excellent stability of metal oxides. The paper concerns mainly ZrO2, TiO2 and Al2O3. Methods of preparation of spherical particles for HPLC are described. Surface chemistry of the oxides is, however, very different from that of silica. Ability of the oxides to ion- and ligand exchange is discussed from a chromatographic point of view.

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Synthesis and thermal stability of zirconia and yttria-stabilized zirconia microspheres

Leib

Vainio

Pasquarelli

et al. 2015

Journal of Colloid and Interface Science

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Zirconia particles (0.4-4.3 μm in diameter, 5-10% standard deviation) synthesized according to the modified sol-gel approaches yielded significantly improved monodispersities. As-synthesized amorphous particles transformed to the tetragonal phase at ∼450 °C with a volume decrease of up to ∼75% and then to monoclinic after heating from ∼650 to 850 °C. Submicron particles disintegrated at ∼850 °C and microparticles at ∼1200 °C due to grain growth. In situ XRD revealed that the transition from the amorphous to tetragonal phase was accompanied by relief in microstrain and the transition from tetragonal to monoclinic was correlated with the tetragonal grain size. Early crystallization and smaller initial grain sizes, which depend on the precursors used for particle synthesis, coincided with higher stability. Yttria-doping reduced grain growth, stabilized the tetragonal phase, and significantly improved the thermal stability of the particles.

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Synthesis of Porous Zirconia Spheres—Mechanism and Prospects for Multistep Processing

Cited by 5 publications

References 9 publications

Fabrication of Monodisperse Porous Zirconia Microspheres and Their Phosphorylation for Friedel–Crafts Alkylation of Indoles

Fabrication of Monodisperse Porous Zirconia Microspheres and Their Phosphorylation for Friedel–Crafts Alkylation of Indoles

Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC

Synthesis and thermal stability of zirconia and yttria-stabilized zirconia microspheres

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