Researchers Develop Sunlight-Based Method to Recycle Black Plastic

A new approach uses carbon black additives in polystyrene to convert waste into reusable materials with sunlight or LED light.

Black polystyrene plastics, commonly used in food containers and coffee cup lids, have been difficult to recycle due to their color and composition.
Scientists from Cornell and Princeton universities have developed a method leveraging carbon black, an additive already present in black plastics, to enable efficient recycling.
The process uses photothermal conversion, where carbon black absorbs sunlight or LED light to generate heat, breaking down the plastic into reusable styrene monomers.
Experiments showed up to 80% efficiency in breaking down black polystyrene under focused sunlight, and 67% efficiency for mixed-color plastics.
This innovation could create a circular recycling process for black plastics, reducing landfill waste and advancing sustainable plastic management.