Vilas Ganpat Pol at the Argonne National Laboratory in Illinois has discovered a way of transforming plastic bags into carbon nanotubes. The chemist who developed the technique calls it ‘upcycling’, which means converting a waste product into something more valuable. He converted waste plastic from throwaway carrier bags into valuable multiwalled carbon nanotubes and even went on to use it to make lithium-ion batteries.
The high or low-density polyethylene was transformed into nanotubes by cooking 1-gram pieces of HDPE or LDPE at 700 °C for 2 hours in the presence of a cobalt acetate catalyst and then letting the mixture cool gradually. The chemical bonds within the plastic breaks down completely when temperature reaches above 600 °C, after which multiwalled carbon nanotubes grow on the surface of the catalytic particles. Although a large number of catalyst is required to obtain good results, but Pol believes this is by far the cheapest and environmentally friendly ways yet found to grow nanotubes.