Lara Estroff - Biogenic and synthetic polymer-reinforced single crystals: Formation and properties

 

Biogenic calcite (CaCO₃) crystals, such as sea urchin spines and the prismatic layer of mollusk shells, are known to incorporate biomacromolecules while still diffracting x-rays as single crystals. The formation mechanisms and materials properties of these nanostructured composites have attracted the attention of materials chemists and biologists. In this work, we characterize the internal structure of calcitic prisms from mollusks and synthetic calcite crystals, which were grown in an agarose hydrogel. The gel-grown calcite crystals, like the biogenic prisms, uniformly incorporate the organic, fibrous matrix. We have also evaluated the parameters that control the incorporation of polymer networks during calcite crystal growth in agarose hydrogels. These results have led to design criteria for polymer-reinforced crystalline materials with unique structure-property relationships. I will also present preliminary results characterizing the mechanical properties of both the biogenic and synthetic single crystal composites. Insights provided by this work may help to elucidate the formation mechanism(s) and properties of biogenic single crystals with incorporated organic material.