The ion exchange characteristics of antimonic acid

Two antimonic acid samples were prepared and designated as hydrolyzed (H-SbA) and refluxed (R-SbA) antimonic acids. Their structure and ion exchange behavior towards Na⁺ as a simple ion is investigated. R-SbA samples showed higher degree of crystallinity and slightly higher ion exchange capacity than the other sample although it had slightly lower water content. Thermal treatment of both samples showed an increase in their ion exchange capacity on heating up to 200 °C. On further heating up to 400 °C the capacity is appreciably decreased. Equilibria measurements of both samples in dilute solutions showed almost an ideal ion exchange behavior. The obtained data are discussed in detail.