1D oriented attachment of calcite nanocrystals: formation of single-crystalline rods through collision

Mihiro Takasaki, Yuki Kimura, Tomoya Yamazaki, Yuya Oaki and Hiroaki Imai, 2016
XRD Pattern
Image courtesy of RSC Advances

Abstract

The oriented attachment of calcite, which is a main component of biominerals, was experimentally demonstrated in an aqueous system at ambient temperatures. Calcite nanoblocks ∼50 nm in size were prepared by carbonation of Ca(OH)2. One-dimensional (1D) alignment of the calcite nanoblocks was induced at ambient temperatures under a basic condition (pH ∼ 12), and single-crystalline rods over 1 µm were then formed through elongation in the c direction. The oriented attachment of the nanoscale building blocks was enhanced by increasing the collision frequency with stirring of the system, but was halted under a neutral pH condition with further carbonation. The controllable non-classical growth mode of calcium carbonate nanocrystals would provide significant information for biogenic and biomimetic mineralization in aqueous solutions.

Impact Statement

As part of a larger study, liquid-cell transmission electron microscopy was used to image the process of one dimensional orientated attachment of calcite nanoblocks in situ.
Keyword: Biomineralization; Nanoparticles: Interactions