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Microwave Pyrolysis of Emulsified Ceramic Precursor Ocompounds

Published online by Cambridge University Press:  15 February 2011

M. Willert-Porada ,
S. Dennhöfer  and
D. Hachmeister
M. Willert-Porada
Affiliation:
University Dortmund, Department of Chemical Engineering, Div. of Materials Science, D-44221 Dortmund, Germany
S. Dennhöfer
Affiliation:
University Dortmund, Department of Chemical Engineering, Div. of Materials Science, D-44221 Dortmund, Germany
D. Hachmeister
Affiliation:
University Dortmund, Department of Chemical Engineering, Div. of Materials Science, D-44221 Dortmund, Germany
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Abstract

Application of paraffin as a MW-transparent matrix for microwave pyrolysis of metalorganic compounds enables synthesis of large quantities of nanosized powders with excellent storability and packing behavior. Fully crystalline, nanosized t-ZrO2 powders with specific surface area > 200 m 2 g -1 are obtained from Zr-alcoholate, and alumina powders with > 500 m2g-1 from Al-alcoholates. Some differences exist between microwave pyrolysis and conventional pyrolysis of such mixtures. Powders from microwave pyrolysis transform at lower calcination temperature to α-A12O3 and exhibit after calcination a more homogeneous morphology as compared to powders from conventional pyrolysis. Furthermore, a different composition of the volatile pyrolysis products is found. t-ZrO2 powder from the microwave processing route exhibits an increased stability towards transformation to monoclinic ZrO2 as well as smaller initial grain sizes than a conventionally synthesized powder.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 347: Symposium O – Microwave Processing of Materials IV , 1994 , 571
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

1. van der Graaf, M.A.C.G., Burggraaf, A.J., “Wet-Chemical Preparation of Zirconia Powders. Their Microstructure and Behavior”, Adv. in Ceramics, 12, 744 (1984).Google Scholar
2. Readey, M.J., Lee, R-R., Halloran, J.W., and Heuer, A.H., “Processing and Sintering of Ultrafine MgO-ZrO2 and (MgO, Y2O3)-ZrO2 Powders”, J. Am. Ceram. Soc., 73(6), 1499 (1990).Google Scholar
3. Willert-Porada, M., Krummel, T., Rohde, B., Moormann, D., “Preparation and Properties of Ceramic Powders Generated by Metalorganic and Microwave Processing”, in “Microwave Processing of Materials III”, edited by Beatty, R.L., Sutton, W.H., Iskander, M.F. (Mater. Res. Soc. Proc. 269, Pittsburgh, PA, 1992) pp. 199–204.Google Scholar
4. Cotton, F. A., in “Progress in Inorganic Chemistry”, Vol. II, p. 336 (1960), and lit. cited there.Google Scholar
5. Schmidt, F., MSc thesis, University Dortmund, 1990.Google Scholar
6. Reynen, P., Bastius, H., and Fiedler, M., “The Use of Emulsions in the Preparation of Ceramic Powders”, in “Ceramic Powders”, edited by Vinzenzini, P., Elsevier Scientific Publ. Comp., Amsterdamm, 1983, pp. 499–504.Google Scholar
7. Hardy, A.B., Rhine, W.E., and Bowen, H.K., “Preparation of Spherical, Submicrometer Oxide Particles by Hydrolysis of Emulsified Alkoxide Droplets”, J. Am. Ceram. Soc., 76 (1), 97–104 (1993).Google Scholar
8. Reynen, P. and Bastius, H., “Hot Kerosene Drying”, Powder Metall. Int. 8, 1976.Google Scholar
9. Hachmeister, D., Willert-Porada, M., unpubl. resultsGoogle Scholar
10. Willert-Porada, M., “Microwave Processing of Metalorganics to Form Powders, Compacts, and Functional Gradient Materials”, MRS Bull., November 1993, p. 51.Google Scholar
11. Dennhöfer, S., Willert-Porada, M., unpubl. resultsGoogle Scholar
12. Willert-Porada, M., “Novel Routes to Microwave Processing of Ceramic Materials”, this volumeGoogle Scholar
13. Willert-Porada, M., Gerdes, T., “Metalorganic and Microwave Processing of Eutectic Al2O3-ZrO2-Ceramics”, this volume.Google Scholar