DEGRADATION IN MECHANICAL PROPERTIES UPON CHLORINE EXPOSURE OF POLYAMIDE BARRIER LAYERS IN WATER PURIFICATION MEMBRANES

 Jung-Hyun Lee, Jun Young Chung and Christopher M. Stafford

Membrane-based desalination has today become the key technology for the production of freshwater from saline sources. Although polyamide (PA) barrier layers of thin-film composite (TFC) membranes for water purification are known to suffer from poor resistance to chlorine attack, little is known about changes in their physical and mechanical properties upon chlorine exposure.  In this study, a methodology based on surface wrinkling and cracking was developed to measure the modulus, tensile strength and elongation at break of ultrathin crosslinked PA films. We successfully probed the change in mechanical properties of PA films as a function of chlorine exposure time. The results allow us to gain insight into the oxidative degradation mechanism of PA barrier layer.