Ship-in-bottle synthesis of the mixed-layered compounds of clay silicate/zirconium phosphate.
An attempt was made to synthesize artificial mixed-layered compounds between montmorillonite silicate and α-zirconium phosphate using a ship-in-bottle approach. The interlayer cations of montmorillonite were first exchanged with hydroxy-zirconium oligomeric cations, which were then subjected to a reaction with phosphoric acid or phenylphosphoric acid to develop α-zirconium phosphate layers (Zr(R-OPO3)2; R = H, C6H5) between the clay silicate layers. The attempt of the reaction with phosphoric acid failed; hydroxy-zirconium cations were removed out of the interlayer space, forming α-zirconium phosphate outside of montmorillonite. The phenylphosphate derivative, montmorillonite/Zr(C6H5OPO3)2, with a regular mixed-layered structure has been successfully obtained, showing a basal spacing corresponding to the sum of the thicknesses of the individual layers. When a polyvinyl alcohol (PVA) aqueous solution was used in the preparation of the hydroxy-zirconium exchanged montmorillonite, PVA was incorporated with hydroxy-zirconium complex cations between the silicate layers. The resulting compound can adsorb phosphate ions. Although this is not a mixed-layered compound in the context of this study, the selective and reversible phosphate ion exchange properties are worth noting for future study.
Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan. syamana@hiroshima-u.ac.jp.
Hiroshi
H
Kawagoe
Naoya
N
Imo-oka
Hiroyasu
H
Shinohara
Shoji
S
Yamanaka