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In this work, we report the distribution ratios of Zr(IV), Co(II), Sb(V) and Nb(V) using polyaniline in HCl, HF, oxalic acid and HF + HCl solutions. Distribution ratios were determined by batch method using radiotracer technique. Further, the separation factors and the %-uptake of metal ions were calculated and compared. Among the media studied, separation factors for Co(II), Sb(V) and Nb(V) with respect to Zr(IV) were the highest in 1 M HCl and the values are 52, 108 and 404 respectively. The results of this study can be utilized for designing an ion-exchange process for the decontamination of zircaloy pressure tubes used in the Pressurized Heavy Water Reactors.

Thermal stability of polyaniline was evaluated to assess its use as ion-exchanger at elevated temperatures. Thermogravimetric analysis of salt (chloride) and base form of polyaniline revealed the decomposition pattern and volatile products. Structural modifications in PAni upon heating upto 500 °C were studied using UV–vis spectroscopy, Fourier Transform Infrared spectroscopy, and viscometry. The gaseous decomposition products of polyaniline were identified using high resolution infrared spectroscopy for the first time. Anion exchange capacity of polyaniline, in terms of ionizable chlorine, determined using Energy Dispersive X-ray Fluorescence spectrometry, was found to be 3.25 meq g −1 . Polyaniline was found to retain ∼90% of the original capacity on heating upto 200 °C. These studies evinced the superior thermal stability of polyaniline over conventional anion exchangers.