Heterogeneous nucleation and growth of crystal bubbles in aqueous solutions and melts - thermodynamic conditions

3D bubbles of calcite (CaCO3) can nucleate and grow encompassing gas cavities previously formed in supersaturated aqueous solutions on solid substrates. Bubbles are single crystals, their size depending on the cavities size (a few micrometers) and the thickness of their double‐wall being lower than a few nanometers. Chemical and mechanical equilibria controlling this heterogeneous nucleation are described in detail, along with the forbidden polynucleation around a gas cavity in aqueous solution. Further, the behaviour of gas cavities in a melt is explained: they can work as poly‐nucleation catalysers since the conditions imposed by the contact angle are fulfilled by the interplay of the interfacial tensions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)