Morphology of BaSO4 crystals grown at the liquid–liquid interface

Abstract

Barite crystals were grown at the interface between an aqueous solution of Ba²⁺ ions and organic solutions of chloroform and hexane containing fatty acid/fatty amine molecules by reaction with sodium sulfate. The crystals grown at the interface in all cases had a nearly similar flat, plate-like morphology consistent with the barite structure. This morphology of the crystals resembles that of barite obtained during growth in solution in the presence of crystal growth inhibitors and is significantly different from that of barite crystals grown at the air–water interface. The use of interfacial effects such as dielectric discontinuity, finite solubility of the two solvents, etc., opens up exciting possibilities for tailoring the morphology of crystals at the liquid–liquid interface.