Turning Plastic into Foam to Combat Pollution

In Physics of Fluids, researchers have developed a method to turn biodegradable plastic knives, spoons, and forks into a foam that can be used as insulation in walls or in flotation devices. The investigators placed the cutlery into a chamber filled with carbon dioxide. As pressure increased, the gas dissolved into the plastic. When they suddenly released the pressure in the chamber, the carbon dioxide expanded within the plastic, creating foaming.