On the real-structure of biomimetically grown hexagonal prismatic seeds of fluorapatite–gelatine-composites: TEM investigations along [001]
| Autor: | Reiner Ramlau, Caren Göbel, Petr Formanek, Jana Buder, Paul Simon, Wilder Carrillo-Cabrera, Rüdiger Kniep, Harald Tlatlik, Dorin Geiger |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | J. Mater. Chem.. 14:2218-2224 |
| ISSN: | 1364-5501 0959-9428 |
| DOI: | 10.1039/b402627f |
| Popis: | The central parts of hierarchically ordered fractal aggregates of fluorapatite–gelatine-composites consist of an elongated hexagonal-prismatic seed (5–20 µm in length). The X-ray diffraction patterns of the composite-seeds (gelatine-content 2.3 wt.-%) correspond to fluorapatite single crystals, the fracture area perpendicular to the hexagonal axis, however, shows a radial structure completely different to the fracture surface of pure apatite. This observation had already led to the assumption of the formation of a nano-composite-superstructure. Here, we report on a TEM investigation into the real-structure of biomimetically grown seeds of the fractal composite aggregates. Because of the high complexity of the composite system the present work is first of all restricted to observations along [001] only. Compared to a pure inorganic apatite mineral the composite is characterised by a superstructure with average periodicity of about 10 nm. The superstructure seems to be caused by calcified (triple-helical) gelatine molecules (orientation of their long axes || [001] of the composite seed) which act as nucleation centres for highly mosaic-controlled apatite-subareas at nano-scale. |
| Databáze: | OpenAIRE |
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