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Characterisation of highly porous glass ceramic scaffolds

X-ray refraction topography and optical microscopic image analysis
  • Wolfram Harbich , Udo Mücke und Georg Berger
Veröffentlicht/Copyright: 26. Mai 2013
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Abstract

Highly porous glass ceramic scaffolds are compared by X-ray refraction topography and optical microscopic image analysis. The micro pore structures of the spongosia-like material are characterised in order to optimise sample preparation and sinter process parameters. In contrast to the specific internal surfaces determined by optical microscopy, significantly higher values are found by X-ray refraction. This discrepancy is explained by additional scanning electron microscopy detecting various types of sub-micron interfaces within the scaffold super-structure. The study demonstrates the necessity of both methods in order to gain more reliable information. More generally, this is also recommended for characterising other porous materials of very different structural dimensions.

Kurzfassung

Schwammartige glaskeramische Biowerkstoffe werden zunehmend als Knochenersatzmaterial verwendet und sind bereits im Tierversuch erprobt. Für den optimalen Einsatz dieser gut resorbierbaren Biowerkstoffe ist eine zuverlässige Charakterisierung erforderlich. Im Vordergrund stehen dabei der Herstellungsprozess, über den die offene Porosität kontrolliert eingestellt wird, sowie der Sintervorgang, der die Struktur des keramischen Gerüstmaterials entscheidend prägt. Hier werden mittels Röntgenrefraktionsanalyse und lichtoptischer Bildauswertung sowohl Porosität als auch die innere Oberflächendichte bestimmt. Während mit beiden Verfahren die Porositäten gut übereinstimmen, weichen die Oberflächendichten signifikant voneinander ab. Dieser Unterschied ist hauptsächlich auf mikrostrukturelle Defekte im keramischen Werkstoffgefüge zurückzuführen, die von der Bildanalyse quantitativ nur unvollständig erfasst werden. Dagegen ist die bildanalytische Auswertung der typischen, großporigen Hohlraumstruktur im Vergleich zur Röntgenrefraktion von Vorteil. Die Untersuchungen zeigen, dass die Kombination beider Verfahren eine geeignete Ergänzung darstellt, um die Strukturparameter verlässlich bestimmen zu können. Dies ist auch die wesentliche Voraussetzung für die Optimierung der Materialeigenschaften.


Dr. rer. nat. Wolfram Harbich, born in 1945, studied physics at the Freie Universität Berlin, where he received his Ph.D. in 1984. His postdoctoral activities have focussed on biophysics, especially lipid bilayer membranes. Since 1989 he has collaborated with the BAM laboratory VIII.32 “General X-ray Topography”, where he is responsible for the development and application of new non-destructive X-ray refraction techniques.

Dr. rer. nat. Udo Mücke, born in 1942, studied crystallography and chemistry at the Humboldt University Berlin, where he received his Ph.D. in 1972. In the following he worked in the field of the development of ceramic materials and ceramography at the Academy of Sciences of the former GDR. Since 1992, he has worked at the Division V.1 “Microstructure of Engineering Materials”, BAM Berlin.

Dr. Ing. Georg Berger, born in 1947, holds a degree in building materials processing from the Hochschule für Architektur und Bauwesen Weimar (1966–1970), Germany, with a major in glass science. As a research student, he was delegated from Weimar to the Institute of Applied Silicate Research at the former Academy of Sciences of the GDR to work in the field of thermal low extensive glass-ceramics. In 1975, he received Dr.-Ing. from the Hochschule für Architektur and Bauwesen Weimar. He worked for many years as a research scientist at the Central Institute of Inorganic Chemistry, Dept. Glass & Ceramics (1975–1992), where he became the head of the biomaterials group. In 1986, he received a further doctoral degree (Dr. sc. techn.) from the former Academy of Sciences of the GDR. Since 1992, he has worked at the Federal Institute for Materials Research and Testing, Berlin, Germany, as head of the project group “Biomaterials and Implants”. His research interests are focused on ceramics, glasses and glass-ceramics on the basis of calcium phosphates for application in medicine and biotechnology.


References

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2 Fensch-Kleemann, F. E.; Harbich, K.-W.; Hentschel, M. P.: “Microstructural characterization of porous materials by X-ray refraction”, cfi/Ber. DKG79 (2002), E 3538Suche in Google Scholar

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4 Mücke, U.; Harbich, K.-W.; Berger, G.: “Determination of the volume and surface densities of pores in spongosia-like glass ceramics by means of image analysis and X-ray refraction”, Praktische Kristallographie, to be published.Suche in Google Scholar

Published Online: 2013-05-26
Published in Print: 2004-05-01

© 2004, Carl Hanser Verlag, München

Heruntergeladen am 25.10.2025 von https://www.degruyterbrill.com/document/doi/10.3139/120.100585/pdf
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