Electrospinning preparation, energetic characteristics and reaction mechanism of corrosion-resistant Si@PVDF nanostructured energetic films

High content of active component, low electrostatic sensitivity and superior long-term storage stability endow n-Si powder unique advantages for application in nanoenergetic composites. In this study, hydrophobic and corrosion-resistant Si@PVDF nanostructured energetic films with different stoichiometric ratios are successfully prepared by electrospinning technique. The energetic characteristics are systematically investigated in terms of thermal analysis, open-air combustion and constant-volume combustion. The results show that Si@PVDF films are microscopically composed of fibers with diameters of about 200–300 nm. With the increase of stoichiometric ratio, more and more n-Si aggregates are found on the surface of fibers. When Si@PVDF is stored in deionized water (50 °C) or NaOH solution (50 °C, 3 mol/L) for 72 h, around 100% and 73.3% of n-Si is retained. Si@PVDF can be thermally ignited, with appreciable heat and pressure output, and the combustion behaviors are strongly affected by the stoichiometric ratio and the environmental conditions. As a comparison, physically mixed Si/PVDF cannot maintain a self-sustained combustion. Through the coupled thermal analysis and mass spectrometry analysis, combined with the morphological and structural characterization of the solid residues, the reaction mechanism of Si@PVDF at a low heating rate is preliminarily obtained.