Percolation transitions in composites formed by the evaporation of droplets of silver nanoparticle dispersions

摘要

Conducting properties are studied for deposits that result from evaporating droplets of dispersions of silver nanoparticles with average diameters of 6.2 and 11.9 nm. The deposits represent two ring-shaped structures with diameters of several dozen and several hundred micrometers, which are formed along the perimeter of an evaporating droplet. It is shown that only the external ring-shaped deposit is an electric conductor. The dependence of its conductivity on the content of metal precursor (AgNO_3) in a solution used to synthesize nanoparticles appears to be similar to a percolation transition. Mechanisms of charge transfer in the examined ring-shaped deposit are discussed assuming that it represents a metal-polymer composite.