Formation of metal (nano-)particles in drying latex films by means of a reducing plasma: a route to auto-stratification

Subjecting drying latex films, the water phase of which contains metal ions, to a reducing, low-temperature atmospheric pressure plasma results in the formation of metal (nano-)particles or a metal film. The process is demonstrated with gold and silver. A continuous metal layer forms on top of the film, when the salt concentration is high enough. At lower concentrations, particles are created inside the film. In the case of gold these are mostly nanoparticles, which are enriched at the top. The reduction drives an auto-stratification process.