Selective Growth of CaCO3 Polymorphs on Aluminum Surface: Effect of Mg2+ ions

Abstract

Aragonite, a hitherto unobservable polymorph by room temperature synthesis has been grown successfully on metallic aluminum surface, following a room temperature carbonation technique. Soluble Al species are detected in the bulk medium due to leaching from the plate surface under the alkaline reaction condition. In addition, when Mg+2 ions are present in the medium, it got precipitated as layered double hydroxide (LDH) by combining with the Al3+ ions on the metallic plate. In presence of Mg+2 ions, the polymorph selection is retained and the relative proportion of aragonite polymorph grown on the aluminum surface progressively increases with time of reaction. Based on these observations and characterization tools, a unified mechanistic approach on stabilization of meta-stable aragonite polymorph on aluminum surface is proposed.