Amorphous Calcium Carbonate: Synthesis and Potential Intermediate in Biomineralization

Amorphous calcium carbonate is produced as spherical particles (see Figure) via in‐situ generation of CO 2 by hydrolysis of dialkyl carbonates in aqueous solution of CaCl 2 at room temperature. This method of synthesis (precipitation) allows detailed studies of the particle formation process. Temperature‐dependent results are rationalized in terms of a phase diagram that assumes a liquid–liquid immiscibility gap with a lower critical separation temperature.