Nanoscale Cavities for Fulleropyrrolidinium in Nafion Membrane

A general method was developed to incorporate fulleropyrrolidinium into the nanoscale cavities of Nafion membrane through electrostatic interaction. The aggregated sizes and structures of fulleropyrrolidinium were controlled by the cavities of Nafion membrane, which were confirmed by XPS and TEM studies. The incorporation was a diffusion-controlled process as evidenced from the absorption spectroscopic method. The absorption spectra of fulleropyrrolidinium nanoaggregates extended to the near-IR region and the fluorescence emission spectra were red-shifted due to the formation of excimers. The resulting fulleropyrrolidinium−Nafion nanocomposites exhibit significant optical-limiting effects at both 532 and 1064 nm, which imply their potential as broadband optical limiters to protect optical devices from damage by lasers.