Technology Explore

Kevlar, the next-generation body armor, to fight germs

For those of you who have never heard of Kevlar, here is a brief introduction to this extraordinary invention and the modern day alchemist Stephanie Kwolek, who invented and patented this material in the 1970s.

Upon graduating in 1946 from the Carnegie Institute of Technology (now Carnegie-Mellon University) with a bachelor’s degree, Stephanie Kwolek went to work as a chemist at the DuPont Company. Her research with high performance chemical compounds for the DuPont Company led to the development of a synthetic material called Kevlar which is five times stronger than the same weight of steel. Kevlar, patented by Kwolek in 1966, does not rust nor corrode and is extremely lightweight. Many police officers owe their lives to Stephanie Kwolek, for Kevlar is the material used in bullet proof vests. Other applications of the compound include underwater cables, brake linings, space vehicles, boats, parachutes, skis, and building materials.

Today, there are three grades of Kevlar available: Kevlar 29, Kevlar 49, and Kevlar 149. If you purchase Kevlar cloth, it is most likely Kevlar 49.

Now researchers at University of South Dakota plan to add germ-fighting to the long list of Kevlar’s features. Yuyu Sun and Jie Luo have developed a new method to coat Kevlar with a substance called acyclic N-Halamine. They tested it against E. coli, Staphylococcus aureus, Candida tropicalis (a fungus), MS2 virus, and Bacillus subtilis spores (to mimic anthrax).

After a short time, large amounts of microorganisms stuck to untreated fabric samples, but the coated fabrics showed little to no adherence of the infectious agents. The coating is long-lasting and can be reactivated if needed, the scientist will report in the Aug. 6 issue of the American Chemical Society’s journal Industrial & Engineering Chemistry Research.

“The resultant fabric materials provided potent, durable, and rechargeable biocidal activities,” the researchers write. “The excellent thermal and mechanical properties of the original Kevlar fabrics were successfully retained after the coating treatment.”

The PMAA-based coating, as it’s called, is said to have antibacterial, antifungal, antiviral, and antispore functions.

“Although more studies are needed to further evaluate the effectiveness of the coated Kevlar fabrics,” the researchers write, “these findings point to the great potential of the PMAA-based coating approach for a broad range of real applications.”