Formation of self-aggregated and interconnected silver network within sol–gel silica

Interconnected silver network inside a sol–gel silica was formed by heat treating a nanoporous sol–gel silica sample containing 10–14 wt% silver ion and minimum of 34 wt% polyethylene glycol and polyvinylpyrrolidone (PVP). This hybrid material was initially translucent when dry, became dark-brown color after exposed to light, and then turned into silver metallic solid after heat-treated at 160 °C. The formation of silver network did not result in sample disintegration. Instead, we found the silver network enhances the compressive modulus of the sample. AFM and SEM images reveal that the unique topographic structures of the silver layer and the silica matrix are related to the amount of polymers. The interconnectivity of the silver structure at the sample surface was assessed by its electrical sheet resistance, which is ~0.003 Ω/sq. The results show that polymer-blended sol–gel silica materials can be used as an alternative template to synthesize interconnected silver network.