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fire porNew military uniform nanocoatings can add fire and UV-light protection and chemical recognition capabilities to uniforms.

In a NATO-funded research, Jaime Grunlan, from the Department of Mechanical Engineering at Texas A&M University, is applying water-based nanocoatings to military clothing, adding protective properties.

Military clothing is made from a variety of textiles such as cotton, wool and synthetic blends. When adding a protective property, the initial benefits of the material are generally lost.

“The reason we like cotton is its soft texture, just like we use nylon because it’s strong,” Grunlan said. “If the cotton is given flame-resistance properties, the fiber itself is modified, and the cotton will stiffen. Similarly, nylon exposed to a flame resistance treatment will weaken. Changing its structure essentially takes away its valuable intrinsic properties.”

Grunlan has developed a water-based, nontoxic solution that can add properties without changing the inherent structure of the clothing. 

A piece of clothing is dipped into a curated solution with a positive charge, extracted, then placed into a solution with a negative charge. The attraction of the opposing charges bonds the chemicals, creating a microscopic nanocoating that adheres to the clothing’s surface in an imperceptible layer.

This technique, commonly referred to as pad-dry processing, can be duplicated with various solutions, creating multiple layers with each new deposition. Each solution is tailored specifically to add certain qualities to the fabric.

A unique aspect of the design is chemical recognition. If the nanocoating is exposed to a hazardous substance, the material will change colors. “Chemical warfare is increasingly becoming a threat,” Grunlan said. “Many chemicals or gases cannot be seen in the air. For that reason, we’re focused on detection based upon a color change, which will notify the user of the chemical agent, allowing them time to react quickly.”

The water-based composition of the solution contributes significantly to its multifunctionality.