Fabrication of silver porous frameworks using poly(ethyleneimine) hydrogel as a soft sacrificial template

This paper describes a new approach to the controllable fabrication of macroporous silver frameworks with various structures and shapes by calcination of Ag nanoparticle-polymer pastes which were mediated by the differently organized linear poly(ethyleneimine) (PEI) hydrogels and silver ions without extra reductant. The porous silver frameworks could be a dome-like shape with inner chambers and can be changed into stair-like crystalline silver film depending on calcination temperature. In addition, macroporous silver monoliths with different porous sizes were easily controllable with changing the preparation conditions of the pastes via routine modulation of the PEI hydrogel and silver ion concentrations. Such changeable features of the silver framework with shape and porous size depending on PEI hydrogels is very unique and would have potential in applications.