Compatibilities & Simulants: Explosive Polymer Interactions

Download Project Report (Phase 2, Year 7)

Project Description

The aim of this project is to develop new methods for those involved in the Homeland Security Enterprise (HSE) to collect, handle, and store novel explosives—often called “homemade explosives” (HMEs)—in a safe and effective manner. Because there are many applications where explosives may interact with other materials, a number of approaches have been developed. To date, the applications of this study have included the development of:

  • Safe-scent aids that contain trace amounts of explosives encapsulated in polymers, which allows the scent of explosives to be released for safe canine training and electronic instrument calibration.
  • Explosive sampling devices (swabs), which are effective at pick-up and release of explosives residues.
  • Better methods for analyzing these hazardous materials.

Because of their volatility, explosives are rarely used in their pure form (meaning without plasticizers or other formulating agents) and instead are often mixed with other materials. This includes both military explosives and HMEs, which may be made safer or more hazardous when mixed with other materials. In either case, it is essential that we understand the consequences of combining HMEs with other materials.

Progress in both the electrostatically enhanced swabs and the canine training aids has advanced sufficiently that their benefit to the TSA is obvious. Swabs, which obviate the need for vigorous rubbing of the surface, speed sampling, provide greater privacy, increase swab lifetime, and minimize collection of interfering compounds. These advantages, coupled with higher pick-up and release efficiencies, will make for speedier, more amenable, and more economical checkpoint operations while improving trace detector performance. The safe-scent aids will provide dog trainers as well as vendors of explosive trace instruments with the option of working without bulk quantities of explosive materials. Presently, vendors must pay exorbitant prices for dilute solutions of explosives, or attain a Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) license and purchase storage magazines and the bulk explosives. Canine trainers often travel with their canine partner and bulk explosives in their vehicles. This is a safety issue, as well as a security concern.


This approach provides canine handlers and instrument vendors with safe access to stored hazardous explosives at trace levels for use in the detection, calibration, and validation of instruments as well as the training of explosives detecting canines.
Year 4 Annual Report
Project Leader
  • Jimmie Oxley
    University of Rhode Island

Faculty and Staff Currently Involved in Project
  • Gerald Kagan
    University of Rhode Island

Students Currently Involved in Project
  • Jeff Canaria
    University of Rhode Island