In situ potassium and hydrogen ion exchange into a cubic zirconium silicate microporous material.

The selective separation of ions from aqueous systems, and even in the human body, is a crucial to overall environmental management and health. Nanoporous materials are widely known for their selective removal of cations from aqueous media, and therefore have been targeted for use as a pharmaceutical to treat hyperkalemia. This study investigated the detailed crystallographic molecular mechanisms that control the potassium ion selectivity in the nanoporous cubic zirconium silicate (CZS) related materials.

In Situ Cs and H Exchange into Gaidonnayite and Proposed Mechanisms of Ion Diffusion.

The microporous mineral gaidonnayite NaZrSiO·2HO was studied to better understand its ion-exchange mechanisms, specifically for Cs and H ions. In situ Raman spectroscopy, in situ X-ray diffraction (XRD), simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), and in situ X-ray fluorescence were used to determine the exchange processes involved. The Raman spectra contain strong peaks that can be attributed to the vibrational modes for the 3MR symmetric stretch at 500 cm, Si-O-Zr-O chain stretches at 938 cm, and Si-O stretching in the 1000-1100 cm range.