Nanoscale cavities for nanoparticles in perfluorinated ionomer membranes

The preparation and characterization of nanoscale silver sulfide and silver particles in Nafion and perfluorinated sulfonimide ionomer membranes are r eported. The results show that the nanoparticles are hosted in the membrane structure in an isolated fashion, with no indication of channels-like doma ins as proposed in the ion cluster model for the ionomer membranes. These r andomly dispersed nanoparticles are also significantly larger than the aver age size of the reverse micelle-like hydrophilic cavities estimated in the literature for Nafion membrane. The properties of the silver sulfide and si lver nanoparticles are presented, and their implications to the understandi ng of membrane nanoscopic structural details are discussed.