Table of Contents
ISRN Analytical Chemistry
Volume 2012, Article ID 514509, 5 pages
Research Article

On the Importance of Purification of Sodium Polystyrene Sulfonate

1Department of Chemical Engineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
2Department of Chemical and Polymer Engineering, Birla Institute of Technology-Mesra, Ranchi 835215, India

Received 22 November 2011; Accepted 28 December 2011

Academic Editors: P. Kingshott and M. Volny

Copyright © 2012 Akhil K. Sen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Ion exchange is commonly employed for purification of sodium polystyrene sulfonate (NaPSS), a molecule widely used as a model polyelectrolyte. However, the present work demonstrates that the ion exchange process itself may introduce some extraneous species into NaPSS samples by two possible mechanisms: (i) chemical transformation of polystyrene sulfonic acid (HPSS), a relatively unstable intermediate formed during ion exchange and (ii) release of small amount of “condensed” acid from cationic resins during the elution of NaPSS molecules. Based on these observations, it is proposed that simple dialysis is adopted as a standard protocol for the purification of primary NaPSS sample.