Pickering emulsion to the construction of spherical nAl/PVDF complexes with excellent thermal properties

Non-uniform mixing of nano-aluminum powder (nAl) with polyvinylidene difluoride (PVDF) affects its thermal properties. Spherical nAl/PVDF complexes were prepared using the Pickering emulsion. Tricosafluorododecanoic acid–modified nAl was employed as the surfactant in the emulsion, enhancing the combustion performance by uniformly combining nAl and PVDF without compromising the system’s energy. The effects of the concentration of PVDF and nAl, the oil-water ratio, and the static duration on the stability of the emulsion were first investigated. It was found that the emulsion had good stability at a concentration of 5~20 wt%, with an oil-water ratio of 1:4~1:7, with a static duration of less than 60 min. The emulsion was extracted and dried to obtain spherical nAl/PVDF complexes. These complexes were then characterized for their morphology, size, thermal decomposition, and combustion properties. The results showed that the complexes were regular spheres with particle sizes of 20–50 μm. They were uniformly complexed on the nano-scale, resulting in enhanced reaction and combustion rates compared to the physical mixture. The exothermic amount was increased by a range of 24.4 to 49.6%, leading to more efficient and stable combustion. The Pickering emulsion presents a new approach for the preparation of nano-fluorinated aluminum thermite.