WATER-ABSORPTION OF THE POLYMER ELECTROLYTE SYSTEMS PB(CF3SO3)2PEON AND ZN(CF3SO3)2PEON

The water absorption behavior has been studied for poly(ethylene oxide ) films (PEO) and for films of M(CF3SO3)2PEOn with M = Zn and Pb and n in the range of 9 to 24. Quantitative measurements of the kinetics of water absorption have been made. Proton nuclear magnetic resonance (N MR) spectroscopy has been used to characterize the effects of water ab sorption on the polymer properties, such as degree of crystallinity an d polymer chain mobility. Impedance spectroscopy measurements have als o been performed on humid samples. Water absorption is found to increa se the mobility of the polymer chain as well as the ionic conductivity of the electrolyte, and a possible mechanism for these effects is pro posed. Water absorption also causes a decrease of the amount of crysta lline phase present in the sample. In addition, deuteron NMR has been used to study the mobility of the absorbed water, demonstrating the ab sence of liquid water surface layers on the polymer, and that the cond uctivity increase observed upon hydration is a property of the hydrate d polymer electrolyte itself.