The central objective of the project research is to develop and demonstrate a process to rapidly synthesize energetic materials through the utilization of non-traditional synthesis methodologies (i.e. confined volumes). Confined volume reactors, which encompass microdroplets, emulsions, thin films, etc. are synthetic methodologies that have shown accelerated product formation, by an order of 10 to 106, when compared to their counterpart traditional bulk reactions, (i.e. a round-bottom flask under reflux) depending on the reaction. The accelerated product formation of highly desired energetic compounds that customarily have lengthy, low-yield or cost-ineffective syntheses, such as synthetic steps in CL-20, will be targeted. The results from the accelerated synthesis of a known energetic syntheses, will be used as a guide for the exploration of alternative accelerated synthetic methods for prediction of other energetic materials and their precursory materials. The ability to screen reactions in confined volumes will lead to an overall decrease in hazardous waste generated by rapidly screening for the most environmentally friendly reaction schemes. This research will help guide future syntheses at production scale, potentially reducing hazardous waste, not only on the research and development stage but throughout the energetics development lifecycle. Through the investigation of the fundamental phenomena that dictate the reaction mechanisms of alternative synthesis methodologies through confined volumes, these accelerated synthetic techniques can be leveraged to shorten the development of novel energetic materials and scale-up processes from milligram to gram quantities used for characterization. This project will seek to systematically answer the questions of what physical processes cause reactions to accelerate in confined volume systems and to what extent each process is responsible for acceleration to create desired products in the fastest and most effective manner possible while decreasing hazardous waste generated.
The process of generating confined volume systems for accelerated synthesis of energetic materials and their precursors will be examined utilizing mass spectrometry ionization sources such as electrospray, nano-electrospray, paper spray, easy ambient sonic-spray, desorption electrospray, as well as, Leidenfrost droplets. The targeted reaction classes will be those with pertinence to common energetic syntheses, specifically condensation, oxidation, and nitration reactions. As different reaction classes will likely have different mechanisms of acceleration, an array of reaction classes will be evaluated to generate a complete overview of how reactions accelerate in each confined volume system to determine the most efficient method of accelerating energetic related reactions.
The work conducted within this project would be the first comparison across each confined volume system for reaction classes. The systematic comparison would enable a wide-range evaluation of which properties have the largest impact on reaction acceleration for each type of reaction mechanism studied, potentially providing a universal factor that can be exploited in future syntheses of new materials and scale up procedures. Understanding these factors would enable forthcoming screening technologies that would drastically reduce the waste generated by the development process of new reaction schemes. The overall decrease in hazardous waste generated will not only apply to the short-term small scale screening and development phase, but also in the future scale up phase. Through the ability to rapidly screen larger quantities of reactions in confined volume systems, the end result ultimately will facilitate more synthetic discoveries, some which could prove to be more environmentally friendly.