Reduce. Reuse. Redefined.

Courtesy Photo | Fabricated laminate swatch contains four layers: Inner layer: soft, high-density knit; Adhesive: thermal glue; MOF layer: MOF-based textile; Outer layer: flexible, tough, flame-resistant material. (NuMat Technologies photo)  

FT. BELVOIR, VA, UNITED STATES

03.28.2022

Courtesy Story

Defense Threat Reduction Agency's Chemical and Biological Technologies Department

Presently, Joint Force protective equipment is effective at neutralizing chemical warfare agents (CWA), but it is a burden to wear. The Defense Threat Reduction Agency’s (DTRA) Chemical and Biological Technologies Department in its role as the Joint Science and Technology Office (JSTO) for the Chemical and Biological (CB) Defense Program partnered with the U.S. Army Combat Capabilities Development Command Soldier Center (DEVCOM SC) and industry performers NuMat Technologies and Guild Associates to create protective overgarments made of lighter materials with improved fit and flexibility for a quick self-detoxifying capability that provides the potential for reuse.

When assuming a Mission Oriented Protective Posture to enter a CB-threat environment, Joint Force servicemembers currently wear an array of protective equipment including a mask, an overgarment, gloves, and overboots to shield them from a full spectrum of CWAs. The overgarment is the Joint Service Lightweight Integrated Suit Technology, which provides effective protection, but it is hot, heavy, and limits breathability. Once the garment reaches sorption capability, it can no longer be used and must be destroyed.

DTRA JSTO is investing in new self-detoxifying materials for the next generation of CB-protective overgarments that can neutralize CWAs within a day and can be washed and reused, which will increase its service life.

The goal of this research is to modernize the materials in the CB-mitigating layer so that it will not only capture and retain chemicals but will also decontaminate CWAs. The researchers’ strategy uses two simultaneous approaches. The first approach uses state-of-the-art lamination techniques to make the garment lighter and more flexible, enabling a better fit. The second approach incorporates new materials that destroy CWAs and could enhance or ultimately replace carbon, which enables the creation of a reusable garment.

This new class of materials comes in two forms: (1) zirconium hydroxide and (2) zirconium-based metal-organic frameworks (MOFs). Both materials absorb CWAs and use environmental humidity to reactively detoxify CWAs, which could make the garment reusable and extend its service life.

A benefit of zirconium hydroxide powders is that they are inexpensive and easy to manufacture. Garment fabrication with zirconium hydroxide places a layer of carbon powder above a layer of zirconium hydroxide. CWAs contact the carbon powder first, where the agent is retained. Over time, from hours to a day, the CWA will leave the carbon and contact the zirconium hydroxide where it will be detoxified. The garment can then be laundered and reused.

MOFs are a class of materials composed of metal clusters coordinated to form porous structures. Zirconium-based MOFs are used in garment production and work with environmental water to directly neutralize CWAs. These MOFs can be engineered to effectively decompose CWAs, interact with CWAs of a specific size, and be densely incorporated into textiles. MOF manufacturing, however, is expensive.

Industry performers collaborate with DEVCOM SC to assess the capabilities of textile swatches. Methods include CWA permeation and detoxification quantification, breathability, abrasion testing, and robustness after laundering. Swatch testing is ongoing. When prototypes are built, DEVCOM SC will compare prototype garment performance against live CWAs (agent protection) and agent simulants (suit robustness, thermal performance, and overall protection).

This collaboration of industry and Department of Defense laboratories will develop self-detoxifying, protective garments that will absorb and destroy contamination within 24 hours instead of just absorbing it like activated carbon. This greatly reduces the risk of contact exposure for the warfighter and enables garments to be reused, which will increase service life and reduce garment costs. Additionally, these new garments should exhibit reduced thermal burden, provide better fit, and maintain the inherent mobility of the Joint Force.

POC: Kendra McCoy, Ph.D., [e-mail]

• Date Taken: 03.28.2022
• Date Posted: 03.28.2022 23:36
• Story ID: 417358
• Location: FT. BELVOIR, VA, US