Fully recyclable, transparent films, which can be used in place of metallized coatings for food packaging, are reported today in Nature Communications. The films can be produced using an environmentally friendly process and could be easier to recycle than some materials currently used in the food-packaging industry.
Increasing the shelf life of food products is an important requirement in today’s economy, but current food packaging poses environmental issues. In particular, multi-material composites comprising metallic layers offer a barrier, essential for food preservation, but are very hard to separate and recycle.
Dermot O’Hare and colleagues produced environmentally friendly, recyclable films that can replace the metallic layer in food packaging, while offering a similar level of protection for food. The authors synthesized thin films consisting of nanosheets of layered double hydroxides (a fully inorganic material) using a cheap, green process that requires water and amino acids. The films are transparent, similarly impermeable to oxygen and water vapour as metallic coatings, and mechanically robust. As the films are synthetic, their composition is fully controllable, improving their safety when in contact with food.
The films already meet safe standards for contact with food, but further tests will need to be conducted before they can be used in packaging.