0000000000646387
AUTHOR
Myriam Hajir
Single nanogranules preserve intracrystalline amorphicity in biominerals.
We revisit the ultrastructural features of different calcareous biominerals and identify remarkable similarities: taxonomically very distant species show a common nanogranular structure, even if different extracellular secretion patterns are employed or calcium carbonate polymorphs formed. By these analyses, we elucidate the locus of the small fraction of intracrystalline organic matrix revealing its intergranular character and localize the intracrystalline amorphous calcium carbonate moiety commonly found in mesocrystalline biominerals and provide a first explanation for the pathway by which it is preserved.
Pseudomorphic transformation of amorphous calcium carbonate films follows spherulitic growth mechanisms and can give rise to crystal lattice tilting
Amorphous calcium carbonate films synthesized by the polymer-induced liquid-precursor (PILP) process convert into crystallographically complex calcite spherulites. Tuning the experimental parameters allows for the generation of crystal lattice tilting similar to that found in calcareous biominerals. This contribution evidences the role of spherulitic growth mechanisms in pseudomorphic transformations of calcium carbonate.
Stable amorphous calcium oxalate: synthesis and potential intermediate in biomineralization.
Amorphous calcium oxalate nanoparticles with sizes of 10–30 nm were synthesized at room temperature by the hydrolysis of a dimethyl oxalate from ethanol solution.