Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 37: Biomaterials

BP 37.3: Vortrag

Freitag, 26. März 2010, 10:45–11:00, H43

The nanostructure of biogenic calcite: a 3D SAXS/WAXS study. — •Christoph Gilow¹, Barbara Aichmayer¹, Chenghao Li¹, Stefan Siegel¹, Oskar Paris², Emil Zolotoyabko³, and Peter Fratzl¹ — ¹Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany — ²Institute of Physics, University of Leoben, A-8700 Leoben, Austria — ³Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel

Biogenic crystals grow in the presence of organic macromolecules which influence their shape and internal structure, often resulting in superior material characteristics. Calcitic prisms from the shell of the Pinna nobilis scatter like single crystals, despite containing significant amounts of intra-crystalline organic macromolecules which cause anisotropic distortions of the calcite unit cells. Individual prisms were investigated by means of 3D wide- and small-angle scattering (SAXS/WAXS) using synchrotron radiation at the µ-Spot beamline, BESSY II, Helmholtz Zentrum Berlin. The SAXS signal was also found to be strongly anisotropic and had a fixed orientation correlation to the WAXS pattern. Additional insights into the nanostructure of calcitic prisms and the organic-mineral interfaces were gained by laboratory SAXS measurements on powdered samples as well as by SEM studies on etched samples. Annealing the prisms at 300^∘C, a temperature which was chosen to mainly affect the organic macromolecules, led to substantial structure rearrangements on a nano-scale.