Abstract
Summary: Gold nanoparticles and nanorods have been synthesized in the ionic cluster network of Nafion using a liquidβphase chemical impregnation/reduction process seemingly visualizing the phaseβseparated hydrated cluster network of Nafion. The spherical shape of the hydrated clusters is clearly seen by the replicated gold nanoparticles with diameters of 5β6 nm. The gold nanoparticles grow through the Nafion cluster network to form gold nanorods with diameters of 5β6 nm and a characteristic length of 12β15 nm, which compare well to the previously reported smallβangle Xβray scattering results. Tiny channels between adjacent spherical clusters are also observed, which expand to form a rod structure by a reorganization of ion exchange sites and an elastic deformation of Nafion polymer chains. The gold nanorods become interconnected in a cascadic feature, and a tripodβshaped nanorod structure is one of the most commonly observed structures of the replicated gold. Although further study should be performed, the synthesized gold may be used to visualize the hydrated cluster and the network structure of Nafion, which could be used as important information in identifying the morphology and ion transport phenomena of Nafion.
Gold nanoparticles and nanorods growing through a hydrated Nafion cluster network.
magnified imageGold nanoparticles and nanorods growing through a hydrated Nafion cluster network.