cg9b00944_si_003.avi (16.3 MB)
Tuning Biotic and Abiotic Calcite Growth by Stress
media
posted on 2019-09-19, 14:47 authored by Bahareh Zareeipolgardani, Agnès Piednoir, Jean ColombaniDuring diagenesis, construction material
hardening, or biomeralization,
the transformation of loose grains into a cohesive solid requires
the crystallites to grow eventually constrained by the surrounding
grains. Whereas it has never been measured, this confinement and the
associated stress are expected to influence noticeably the growth
and the final properties of the material. We report here on atomic
force microscopy measurements of atomic step velocity during calcite
growth, with a varying stress applied by the tip to the surface. The
stress has a double influence: it both slows the growth and modifies
the material crystalline phase. Furthermore, the addition of a small
quantity of oligopeptide is shown to have no significant influence
on the kinetics but to completely cancel the phase change under stress.
Our results emphasize the previously unknown role of stress on growth
mechanisms and identify a new possible role of organic molecules in
tuning the morphology of biomineralized materials.