Printable Nanoporous Silver Membranes

We present a facile, broadly applicable method to prepare nanoporous silver films using soluble salt nanoparticles as pore templates. The fabrication starts by printing a silver/CaCO(3) nanoparticle based ink onto a flexible substrate and removing the CaCO(3) by washing in a weak acid. The membrane thickness and pore size can easily be tuned between 0.5-5 mu m and 30-300 nm, respectively, by a simple pH or temperature treatment (sintering at 200 degrees C). As a conceptual demonstration of the resulting large-area, defect-free, and homogeneous microstructure, we use these membranes to efficiently filter aqueous dispersions of carbon nanoparticles (20 nm primary particle size) at a filtration efficiency of > 99.6%.