Silver Foam: A Novel Approach for Long-Term Passive Dosing of Biocide in Spacecraft Potable Water Systems – Update 2020



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2020 International Conference on Environmental Systems


A spacecraft water disinfection system suitable for extended length space exploration missions should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically-influenced corrosion. In addition, the system should have minimal maintenance requirements, the effluent should be chemically compatible with all materials in contact with the water, be safe for human consumption, and suitable to be shared across international spacecraft platforms and mission architectures. Silver ions are a proven broad spectrum biocide and the chosen potable water biocide for future exploration missions. The leading technology for actively dosing silver in future water systems is based on electrolytic production. Several challenges remain with this approach which have prompted additional investigations into alternative dosing techniques. Control-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the development of a nanoparticle (NP)/polyurethane (PU) composite foam for the controlled release of silver ions, and is intended to build upon the 2019 International Conference on Environmental Systems (ICES) paper of the same name. In this paper, the technical background and results from the updated nanoparticle (AgNPs)/PU composite foam synthesis and property testing is provided. The ultimate goal of the project is to develop a stable and reliable passive dosing silver ion release device for use in future spacecraft potable water systems.


Tesia Irwin, The Bionetics Corporation, US
Wenyan Li, Vencore-ESC, US
Angie Diaz, URS Federal Services Inc, US
Luz Calle, National Aeronautics and Space Administration (NASA), USA
Michael Callahan, National Aeronautics and Space Administration (NASA), USA
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.


silver biocide delivery mechanism, silver composite foam controlled release, polyurethane foam disinfectant