Mercaptophenol-protected gold colloids as nuclei for the crystallization of inorganic minerals:: Templated crystallization on curved surfaces

The self-assembly of monolayers of thiols on gold(111) surfaces yields substrates that are able to template in a controlled manner, the nucleation and growth of crystals of calcium carbonate from solution. In the absence of additives, various factors such as the nature of the thiol, the temperature, and the pH are now established as influencing the nature and relative amounts of the different CaCO3 phases (calcite, vaterite, and aragonite). Recently, we have been able to extend the use of thiol/gold self-assembled monolayers as templates for the growth of inorganic crystals by utilizing protected gold colloids instead of flat gold surfaces. The thiol monolayers that protect the colloids provide heterogeneous interfaces for the initial nucleation of the inorganic crystal. The utility of such a designer seeding is demonstrated through the crystallization of CaCO3 in the calcite modification and SrCO2 in the strontianite modification.