U.S. Army Researchers Develop Graphene Filters for Water, Air Purification

Scientists at the U.S. Army Engineering Research and Development Center (ERDC) in Vicksburg, MS recently received two patents for developing a water filter made by combining a product sourced from skeletons of sea animals and graphene.

The CSGO (Chitosan/Graphene-Oxide) film, referred to by developers as GO film, was developed to serve as a high volume water filter for the military, but future applications may also serve as a filter for air as well as an additive to strengthen asphalt.

Chitosan is extracted from the external skeletons of sea animals and often is sold as a fat blocker in over the counter products. Graphene is the thinnest, strongest material known and is often described as a disruptive technology that will impact all areas of business and industry.

The ERDC team who produced the patented filter includes Dr. Victor Medina, Dr. Chris Griggs, Mr. Jose Mattei-Sosa, Ms. Brooke Petery, and Mr. Luke Gurtowski.

“Our research group was focused on overcoming scalability challenges for graphene oxide (GO) so we developed the chitosan/ graphene oxide (CSGO) as means to produce a viable material at scale,” said Dr. Chris Griggs. “The key discovery was that we could harness the functionality of GO through synergistic interactions within the composite. Currently we are enhancing the oxidative properties of GO for effective inactivation of pathogens for environmental and water treatment applications.”

“We produced the pre-filter for a user in California using our chitosan/graphene oxide formulation,” said Dr. Victor Medina. “They would like to use the filter to recover ethanol from a small industrial operation. The CSGO was cast into a film, then cut to cover the existing filter. It was covered with a support material like nitrile, then with a light plastic mesh.”

Medina said the group is also exploring applications in air filtration and perhaps as an enrichment to asphalt.

“We have done some experiments using the films to isolate contaminants for military vehicle applications,” Medina said. “GO films can be manufactured in almost any size suggesting enormous potential in a wide range of applications. A report of these applications was published in ResearchGate.net and describes the use of the film to protect military hardware in the event of germ agents.”

“The first (patent) was for a method of recycling the SGO members. No one had previously had a method for recycling after treatment membranes. The second was for the manufacturing process for CSGO membranes. Our process allows for the production of graphene oxide membranes in any size,” Medina said.