Crystallization of aluminum polycation sulfates: transformation of tetrahedral crystals into block crystals in aqueous solutions†
Abstract
Novel crystalline transformation of Al polycation sulfates from tetrahedral to block shape was observed spontaneously in aqueous solution. Theoretical calculations revealed that the transformation reaction was driven by thermodynamics, which led to the dissolution of Na+ from Al13 polycations in the crystal lattice. A new crystalline phase was formed by subsequent re-organization and re-growth.