Synthetic Melanin Filtration Agents

Science Center, Bent Corridor

Melanins, the biological pigments have a range of interesting properties that make them potentially beneficial as water purification agents. Natural and synthetic melanins are known to bind a variety of organic compounds and metal ions, including lead. As seen in current events like Flint, Michigan and the escalation of lead in water reports in Chicago public schools, lead is continuing to grow as a health concern in drinking water within our communities. Working in collaboration with a local company, Nanotech Innovations, we are exploring synthetic melanin in combination with a variety of other materials, including carbon nanotubes, alumina nanoparticles, and activated carbon, as filtration agents for heavy metals and organic dyes. We are currently focusing on a composite material composed of synthetic melanin, carbon nanotubes, and activated carbon for lead filtration. We are able to test the effects of synthetic melanin in different lead concentrations through oxidation of L-Dopa and synthesizing the material with carbon nanotubes on activated carbon, supplied by Nanotech Innovations. The resulting product, Mel/CNT/AC, is used to filter lead solutions that were equilibrated for 18 hours and analyzed through atomic absorption spectroscopy. This product was compared by filtering the same lead concentrations with untreated CNT/AC. Our composite material shows that the addition of the melanin coating on the CNT/AC has a greater affinity of lead binding compared to the untreated CNT/AC. This led our lab into finding options in optimizing lead binding through changes in pH during the synthesis. As a result, in having different ranges in pH, we see greater lead binding on the Mel/CNT/AC. Throughout this year, we hope to continue testing different synthesis and lead binding conditions for the Mel/CNT/AC composite materials.