Fumed oxides as base materials for ceramic applications

Hartmann, W.; Liu, A.T.; Peuckert, D.; Kleinschmit, Peter

doi:10.1016/0921-5093(89)90594-7

Cited by 26 publications

(9 citation statements)

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“…Silica is used to control thickening, thixotropy, and reinforcement [28], as well as a stabilizer for suspensions, free flowing, or as a chemical mechanical polishing (CMP) agent [29]. Carbon blacks, however, are the most important fillers in rubber industries.…”

Section: Nanoparticles By Combustion Of Gasesmentioning

confidence: 99%

Flame Synthesis of Nanoparticles

Kammler

Mädler

Pratsinis³

2001

Chem. Eng. Technol.

394

208

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An overview of recent advances in the synthesis of nanoparticles by flame aerosol processes is given. In flame processes with gaseous precursors emphasis is placed on reactant mixing and composition, additives, and external electric fields for control of product characteristics. Thermophoretic sampling can monitor the formation and growth of nanoparticles, while the corresponding temperature history can be obtained by non-intrusive Fourier transform infrared spectroscopy. Furthermore, synthesis of composite nanoparticles for various applications is addressed such as in reinforcement or catalysis as well as for scale-up from 1 to 700 g/h of silica-carbon nanostructured particles. In flame processes with liquid precursors using the so-called flame spray pyrolysis (FSP), emphasis is placed on reactant and fuel composition. The FSP processes are quite attractive as they can employ a wide array of precursors, so a broad spectrum of new nanosized powders can be synthesized. Computational fluid dynamics (CFD) in combination with gas-phase particle formation models offer unique possibilities for improvement and possible new designs for flame reactors.

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Section: Nanoparticles By Combustion Of Gasesmentioning

confidence: 99%

Flame Synthesis of Nanoparticles

Kammler

Mädler

Pratsinis³

2001

Chem. Eng. Technol.

394

208

View full text Add to dashboard Cite

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“…[8,9] Hung et al [10] report on the formation of mixed oxide powders consisting of silica, alumina, germania, and titania using a counterflow diffusion flame burner. Hartmann et al [11] present the production of highly dispersed ZrO 2 -, Al 2 O 3 ±TiO 2 -, and SiO 2 -doped powders by high-temperature hydrolysis of gaseous metal chlorides. Vollath and Szabo [12,13] prepared particles (of sizes below 10 nm) consisting of alumina±zirconia and maghemite±zirconia with a core-shell structure, in a twostep microwave plasma process.…”

Section: Introductionmentioning

confidence: 99%

Controlling Surface Composition and Zeta Potential of Chemical Vapor Synthesized Alumina‐Silica Nanoparticles

Sieger¹,

Winterer

Mühlenweg³

et al. 2004

Chemical Vapor Deposition

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Ultrafine alumina-silica powders with varying composition gradients within the particles have been produced by chemical vapor synthesis in a hot-wall reactor using the precursors tetraethoxysilane (TEOS) and aluminiumtrisecbutylate (ASB). The surface chemistry at the particle/liquid interface in aqueous dispersions can be adjusted by varying the process parameters. The powders have been characterized by nitrogen adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) with local energy dispersive X-ray (EDX) analysis, X-ray fluorescence (XRF) analysis, and electrophoretic mobility measurements.

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“…The process is widely employed in industry for the large scale production of the oxides of silicon and titanium. Other oxides, e.g., aluminum and zirconium oxide (Hartmann et al 1989), can be made; however, the lower vapor pressure of the respective chlorides necessitates a more complicated arrangement. In general, many elements do not form volatile halides, so this approach can be employed in the case of only a few elements.…”

Section: Introductionmentioning

confidence: 99%

A Novel Aerosol Combustion Process for the High Rate Formation of Nanoscale Oxide Particles

Kilian¹,

Morse²

2001

Aerosol Science and Technology

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We report a new method for the high rate formation of nanophase ZrO 2 and Al 2 O 3 powders. In the experimental arrangement, a solution of metal alkoxides in their parent alcohols is converted into an aerosol of approximately 30 ¹ diameter droplets by means of an ultrasonic spray nozzle. The aerosol is mixed with oxygen immediately after formation and combusted in a specially designed burner at high temperature. The resulting oxide particles are thermophoretically collected and examined using TEM and X-ray diffractometry. A novel, patented, burner design permits a signicant reduction in temperature gradients normal to the ame. As a consequence, it is possible to obtain signi cantly better control over particle size and morphology and, in addition, hard agglomerates are absent. This is a signi cant departure from the process found in a typical ame reactor. With this technique, spherical, unnecked particles in the range from 5 to 140 nm (peaking sharply at 40 nm) are produced. There is no correlation between the initial liquid droplet size and the nal particle size. The method was successfully applied to the formation of zirconium and aluminum oxide at synthesis rates in excess of 3 g/min. Experiments to measure the ame temperature using an optical technique yielded temperatures between 2300 K and 3000 K, depending on the position in the ame and the type of precursor solution used. We note that this technique can be readily extended to more complex oxides such as YAG and BaSrTiO 3 . INTRODUCTIONDuring the past several years a large number of methods for the production of nanoscale oxide particles have been reported. Oxide powders with particles sizes in the range below 100 nm are important in many applications that include ceramic products, catalysts, and paint opaci ers. The approaches taken in their synthesis can be divided into wet chemical and gas phase (aerosol) methods. Among the former is the precipitation of particles from a suitable homogeneous precursor solution (Ciftcioglo and Majo 1990) and the wet hydrolysis of metal alkoxides in solution (Smith et al.; Ingebrethsen and Matijevi).

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Fumed oxides as base materials for ceramic applications

Cited by 26 publications

References 0 publications

Flame Synthesis of Nanoparticles

Flame Synthesis of Nanoparticles

Controlling Surface Composition and Zeta Potential of Chemical Vapor Synthesized Alumina‐Silica Nanoparticles

A Novel Aerosol Combustion Process for the High Rate Formation of Nanoscale Oxide Particles

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