Studies on the Colloidization and Stability of Layered M(IV) Phosphates in Aqueous Amine Solutions

Abstract

For the purpose of preparing pillared materials and multifunctional films,the colloidization and hydrolysis of α-Zr(HPO4)2·H2O(α-ZrP), α-Sn(HPO4)2·H2O (α-SnP)and α-Ti(HPO4)2·H2O (α-TiP) in alkylamineand alcohol amine solutions were investigated. The phosphates colloidizeat a low level of amine intercalation but recrystallize at high levels ofamine uptake. Alcohol amines are more efficient in colloidization ofphosphates than alkylamines, and in the same amine solution α-ZrPand α-SnP colloidize more readily than α-TiP. Thehydrolytic reaction of the phosphates following the course of intercalationin different amine solutions were studied. The dissolution of the metal ionsaccompanying the hydrolysis of HPO42- leads to the destruction ofthe sheet structure. The strong hydrolytic reaction of α-TiP causesit to colloidize with difficulty. The phase transformations of the wet amineintercalates during air drying were detected by XRD. The interlayer aminemolecules may arrange in monolayer, bilayer or intermediate orientation,depending on the nature and content of the amines.