A new chemistry was developed for existing hydrazine absorbent/detoxification pads. Enhancements include faster reaction rates, weight reduction, a color change that indicates spill occurrence, and another color change that indicates successful hydrazine degradation. The previous spill control pad, using copper oxide on the silica gel substrate as the reactant, affected only 50 percent degradation of hydrazine after 9 hours. The new prototypes have been found to degrade hydrazine from 95 to 99.9 percent in only 5 minutes, and to below detection limits within 90 minutes.

The new design benefits from an approximately four-fold decrease in reagents mass. The color change abilities of this new design also are useful to show when a spill has occurred somewhere that makes observing the spill difficult. The pale blue surface turns brown or black when hydrazine solutions spill on it. The pad is self-indicating for the completion of the reaction. Retention of the aqua blue color of the solution in the pad after 15 minutes indicates that the detoxifying of the reagents is in excess of the hydrazine absorbed. Conversely, if liquid squeezed from the pad is only a faint blue, this indicates that hydrazine was in excess of the detoxifying reagents, and the reaction is incomplete.

Tests performed at the White Sands Test Facility confirmed the efficacy described above for wet treatment pads, but found incomplete reactions and overheating occurred with pads that were allowed to dry out before testing, indicating that desiccation should be avoided.

This work led the innovators to continue to work with hydrazine-related products. They have since developed a new patented method for the complete and safe remediation of hydrazine. They use a safe nontoxic organic compound that quantitatively converts hydrazine into a new nonhazardous organic product. This process is now a commercial product that is currently being marketed as ZeenKleen.

This work was done by Merritt C. Helvenston of New Mexico Highlands University for Johnson Space Center. MSC-23812-1

NASA Tech Briefs Magazine

This article first appeared in the August, 2014 issue of NASA Tech Briefs Magazine.

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