The objective of this project is to enhance the understanding and performance of fluorine-free (F-free) siloxane and glycoside based formulations for fire suppression on fuels to include polar solvents, gasoline, and gasoline-alcohol blends. The project team will synergistically integrate both molecular modeling and experimental investigations to efficiently explore and optimize molecular functionalization. The rates of formation of surfactant ordered structures at the aqueous-air interface and aqueous-fuel interfaces along with their stability and surface tension will be linked to specific molecular interactions and enhanced through rational design and computational screening of trisiloxane derivatives and/or incorporation of additives to improve the F-free formulation for diverse fuels. For the optimized formulation the project team will characterize the impacts of operational temperature and fresh/salt water on the surfactant dynamic mechanisms.

The approach of this project is to leverage computational capabilities recently developed at Engineer Research and Development Center to exploit links between the molecular interactions in solution, aggregation, and at interfaces that impact the fire suppression performance of F-free formulations. Experimental studies of the formulation ingredients will be available to inform the modeling and validate key assumptions. The project team will use rational design to optimize the molecular interactions that most enhance fire suppression against target fuels and screen possible functionalization and additives computationally and in the wet lab. Iterative feedback will hone the understanding of the phenomena and the accuracy of the modeling. Impacts of salinity and operating temperature on the optimized formulations will be characterized in silico and experiment. The end result will be improved fire suppression performance against fuels that include polar solvents, gasoline, and gasoline alcohol blends.

This project will create a better understanding of how molecular features translate to fire suppression performance and result in formulations with improved fire suppression against various fuels. The effects of salinity and operating temperature will also be characterized in regard to the enhanced formulations together with the model data providing novel insight into the key molecular features driving those properties. The project expects to produce four peer-reviewed publications, conference presentations, and have formulations with enhanced activity against diverse fuels to make available for further characterization and testing against the strict requirements of the U.S. DoD’s Mil-F-24385F specification.