Description:
OBJECTIVE: Develop responsive spreadable coatings that undergo a change in state upon exposures to environmental stimulus including chemical vapors and/or chemical or biological aerosols. The response should help to mitigate the associated contamination through driving disclosure, sequestration, and/or detoxification. DESCRIPTION: Coatings are typically used to improve/protect its underlying surface from the environment and blend in with its surroundings. The US DoD employs coatings in a wide variety of applications ranging from corrosion prevention to radar absorption. More recently, sequestration coatings for radioactive materials have been developed and evaluated. A standard for such a coating was put forth by the US EPA that references several important characteristics including the capacity to physically and chemically bind dispersible radioactive contamination; be removable during subsequent decontamination and recovery operations; act as a decontamination agent and withstand a degree of mechanical abrasion, weather effects, and environmental conditions among others. A similarly purposed coating for chemical contamination is desired. The coating shall be deployed after contamination is deposited on a surface and should offer an immediate barrier to contact and vapor hazards resulting from encapsulated contamination. Ideally, the coating can be applied as a liquid or spray-on gel. The coating should release no volatile solvents (VOCs), including water, during application, curing or treatment (solvent evaporation may release toxic agent into air). The coating shall also entrain the surface contamination, protecting the underlying surface from effects of the contamination and rendering it removable when the coating is removed in the future. The coating must be able to be applied to surfaces with heavy chemical loading (10 g/m2) without disruption of performance degradation of the sequestration properties. Ideally, in the future, the coating would both indicate the location of contamination within the coating and also drive its detoxification. The sequestration coating will be robust but also easily removed from the substrate such that upon removal, the underling surface will be thoroughly decontaminated but not damaged. The coating should remove/neutralize 99% of the residual chemical warfare agent challenge within 100 hours after application under ambient operating conditions. Existing performance data with chemical warfare simulants or live agents will be valuable in evaluating submissions. PHASE I: Demonstrate the ability to sequester chemical agents within an applied coating material, both removing them from an underlying surface and neutralizing the agents while keeping them from breaking through the coatings as contact or vapor hazards. A successful Phase 1 effort should conclude with a demonstration on at least three chemical agent simulants. Demonstration on one live chemical agent using an approved surety lab is desirable but not required. PHASE II: Based on the results of the preliminary testing of Phase I, perform a thorough assessment of the coating"s capacity to handle different doses of simulants and agents that were applied to relevant surfaces in different forms (fine mist, small droplets, large droplets). Phase II should further demonstrate disclosure / detoxification capabilities of the coating while ensuring that coating removal does not irreparably damage the underlying surface. Phase II should also demonstrate the ability of the coating to indicate the presence of agent under the coating. The successful offerer will also demonstrate that the coating employed is manufacturable at a scale and cost that are conducive to wide area military applications. PHASE III: Develop a commercial system for application of the coating that can be used throughout the U.S. DoD. The effectiveness of the coating should be fully quantified against live agents in 3rd party tests. Appropriate approval from regulatory agencies, such as the EPA should be sought as necessary for field application of the coating. A likely transition path for the technology is through the Joint Program Executive Office for Chemical and Biological Defense (JPEO-CBD). This technology would also have broad civilian application in hazardous material spill clean up. REFERENCES: 1. Drake, J. 2009. Sequestration Coating Performance Requirements for Mitigation of Contamination from a Radiological Dispersion Device. Waste Management Symposium WM"09 Conference, March 1 - March 5, 2009, Phoenix, AZ. 2. Test Operations Procedure (TOP) 8-2-061."Chemical and Biological Decontaminant Testing,"19 November 2002. Available through the National Technical Information Service (www.ntis.gov).
