Ion Exchange Behaviour of Some Amine Intercalates of α-Tin(IV) Hydrogen Phosphate Monohydrate

Abstract

The ion exchange behaviour of some amine intercalation compounds of α-tin(IV) hydrogen phosphate (α-SnP) has been investigated in the presence of transition metal ions. It has been found that the behaviour of these intercalates depends upon whether the guest molecule is a mono-or a polyamine. For each of the intercalation samples studied the rate of uptake of the metal ion is rapid (t_1/2 less than five minutes). When the guest molecule is a primary monoamine the uptake of the metal ion is accompanied by the loss of the amine in the form of a soluble alkyl ammonium ion. The resultant solid product of this reaction is essentially amorphous due to the delamination of the lamellar α-SnP. The surface areas, however, are approximately the same (α-SnP 51.6 m² g⁻¹, the delamination product 55.9 m² g⁻¹). The retention capacities of the α-SnP allylamine intercalate for Ni²⁺, Co²⁺ and Cu²⁺ were 6.3, 5.9 and 3.5 meg/g respectively. This intercalate appeared to be selective for CU²⁺ especially at low copper concentrations in mixed solutions.