Just published in RSC Advances, a new paper from work I did with Johan Linden, Mikael Larsson, Bill Skinner, and Magnus Nyden:
Polyethyleneimine for copper absorption: kinetics, selectivity and efficiency in artificial seawater
The surprising result was that a simple, industrial polymer was so effective at first binding metal ions but then, over time, having a greater affinity only for copper leaving the film to be enriched only in this metal.
Thus, copper can be scavenged selectively from low concentration seawater solutions. This has implications for removal of toxic copper from marinas — an environmental problem caused by leaching of copper from antifouling marine coatings.