Optimizing the Interfaces of Energetic Textiles with Perfluorinated Oligomer-Coated Aluminum Nanoparticles: Implications for Metastable Intermolecular Composites

Metal powders have long been utilized as the primary fuel component in many conventional pyrolant-based energetic materials. Significant enhancements to their energetic performance are realized with metal powders composed of nanometer-sized particles due largely to the increase in specific surface area (SSA). Reaching the greatest possible weight percent loading of metal nanoparticles requires optimization of the interface between the metal fuel and the polymer matrix. In this work partially fluorinated perfluorocyclobutyl (PFCB) microfibers loaded with nanothermite formulations, composed of aluminum nanoparticles (nAl) coated with different perfluoropolyether (PFPE) oligomers, were successfully fabricated via electrospinning to produce nonwoven mats of energetic thermite microfiber. The resulting energetic textiles were composed of high SSA microfibers with highly uniform fiber diameters at fuel loadings upward of 35 wt % nAl content well dispersed in the fiber matrix. The metalized fibers were found to have smaller and more uniform diameters and possessed nAl loadings an order of magnitude greater than our previously reported polystyrene-based electrospun fiber composites. Furthermore, characterization of fiber morphology, particle dispersion, flame propagation, and the thermal properties of the PFCB/PFPE/nAl based nanothermite textiles are presented in this work to demonstrate a sensitive dependence of many fiber characteristics on the interface between the coated metal particle fuel and the polymer matrix.