Plastics products—such as grocery bags, packaging foam, plates, and cups—are lightweight, strong, and inexpensive to produce. However, because these products are not biodegradable, they collect in landfills, litter the environment, and present a long-term environmental problem. Through a new process developed by an Argonne scientist Vilas Pol, a wide range of waste plastics can be converted into a fine black carbon powder or carbon nanotubes. This carbon-based substance has numerous industrial applications, ranging from its use as an anode material in manufacturing lithium-ion batteries to serving as a component in water purification, tires, electronics, paints, and printer inks and toners.
Plastic bags have become a fact of life for businesses and consumers. According to the U.S. Environmental Protection Agency, Americans use over 100 billion plastic bags annually, but only about 13% are recycled.
Plastics are not biodegradable. They collect in landfills and litter roadsides. Scientists say plastics take more than 100 years to decompose. Conventional recycling methods are ineffective because different types of plastics—polystyrene and polyethylene, for example—cannot be mixed and the quality of recycled plastic is typically poor.
At Argonne, chemist Vilas Pol has devised an environmentally green method that breaks down plastics and transforms them into a highly usable substance. In Dr. Pol’s solvent-free process, plastic bags are inserted into a specially designed reactor and heated to 700 degrees Celsius, forming a fine black powder. The powder contains tiny carbon spheres— around 2 to 5 micrometers wide and one-twentieth the width of a human hair.
If a cobalt-based catalyst is added during the heating, the powder forms microscopic carbon nanotubes. Both substances—carbon nanotubes and carbon spheres—have numerous industrial applications. They are used to manufacture lithium-ion batteries, which power cell phones, laptops, and other products. The batteries also serve as the power source for electric cars. Moreover, the properties of carbon micropheres make them useful in water purification and the tire industry, as well as in the manufacture of paint, printer inks, and toners.
Applications and Industries
- Electronics (lithium-ion batteries for cell phones, laptops, electric cars and more)
- Water purification (for adsorption properties)
- Tires (for heat-dissipation properties)
- Paint (unique spherical morphology with conducting nature)
- Computer inks and toners (highly suitable micrometer size)
- Enables the effective removal of a nonbiodegradable plastic from the environment (currently, a leading cause of environmental waste).
- Introduces a cost-effective, environmentally green method for transforming plastics into a useful commodity.
- Provides a new source for a commodity, the properties of which make it useful in other industries, including manufacturing.