Dresden 2017 – wissenschaftliches Programm
CPP 10.7: Vortrag
Montag, 20. März 2017, 16:45–17:00, ZEU 114
Nonclassical Crystallization in vivo et in vitro: origin and mimesis of a fundamental and nanoscale process-structure-property relationship of biominerals — •Stephan E. Wolf — Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany; Juniorprofessor for Biomimetic Materials and Processes
Hidden within their structural wealth, a distinct nanogranular fine structure is shared by nearly all biominerals. This structural dichotomy of universality vs. diversity roots in a common nanoparticle-mediated growth, i.e. nonclassical crystallization, which underlies the formation of these nanogranular biominerals. This reveals a fundamental process-structure-property relationship of biominerals since the nanoscale organic-inorganic composite design affects multiple properties of the bioceramic. The mimesis of such a nanogranular material can be readily accomplished by exploitation of an in vitro mineralization route which involves accretion of amorphous colloids and their subsequent solid-amorphous to solid-crystalline phase transformation. This model system allows an unpreceded view on the mineral phase transformation and allows further the mimesis of crystal lattice tilting and twisting as observed in biogenic minerals. We discuss the origin of this peculiar crystallographic feature and demonstrate that crystal lattice bending represents a powerful, yet unexploited means to design and dynamically control anisotropic properties of a crystalline material. Revelation of the underlying mechanisms may pave the way to new classes of gradient materials and provide a new view on crystallographic design of solid state materials.