The Ion-exchange Behavior of the Ammonium Ion on Crystalline Zirconium Phosphate

Abstract

The ion-exchange behavior of the ammonium ion on crystalline zirconium phosphate (c-ZrP) was studied by pH titration and X-ray powder diffraction. The ion-exchange capacity of c-ZrP was 4.4 meq/g in an acidic solution and 6.6 meq/g in an alkaline solution. At an exchange of 66% the Zr(NH4PO4)1.33(HPO4)0.67·H2O phase was present and at an exchange of 100% Zr(NH4PO4)2·H2O phase was present. The forward and backward titration curves exhibited a hysteresis loop. This results from the presence of the different phases in the titration of each direction. Through the ion-exchange cycle, the crystallinity of c-ZrP was maintained.

Surface Functionalization of Zirconium Phosphate Nanoplatelets for the Design of Polymer Fillers

“…11°. This peak is likely a combination of two peaks with d values of 8.2 Å and 7.6 Å which were reported by Hasegawa and Aoki as the initial indication of the re-exchange of protons into NH 4 + @ZrP . The intercalation of ammonium within ZrP is highly ionic in nature, each ammonium is surrounded by the maximum number of negative charges and the water molecules positioning is based upon the location of the ammonium .…”

“…Two phases are possible when intercalating ammonium ions into ZrP, the fully loaded phase in which there are 2 moles of ammonium ion per Zr, and the half loaded phase which has a 1:1 ratio of Zr:NH 4 + . , Composites were successfully prepared for the fully loaded phase, and the effect of the encapsulated molecule on the thermal stability of the nanocomposites was investigated. Initially the composite films were analyzed by XRPD.…”