微流控组装nAl@PVDF@CL‑20复合含能微颗粒的制备与表征

The explosives and propellants containing hexanitrohexaazaisowurtzitane (CL‑20) and aluminum (Al) powders show excellent energy properties, and Al/CL‑20‑based energetic materials have become the focus of research. By using polyvinylidene fluoride (PVDF) as binder combined with nano‑aluminum (nAl) powders and CL‑20, the nAl@PVDF and nAl@PVDF@CL‑20 composite energetic particles could be prepared via microfluidic technology. The morphology, internal structure, and particle size of two composite particles were observed by scanning electron microscope (SEM) and laser particle size analyzer. Chemical structure of composite particles was analyzed by Fourier transform infrared spectrometer (FTIR). Thermogravimetry‑differential scanning calorimetry (TG‑DSC) was used for thermal analysis. The results show that the as‑prepared composite particles exhibit high sphericity, good dispersibility, and uniform particle size distribution with the particle size of 10-20 μm. The components of composite particles are well‑distributed, and there is no chemical bond between the components. Thermal analysis results display that both nAl@PVDF and nAl@PVDF@CL‑20 composite particles exhibit pre‑ignition reaction between PVDF and surface oxidation layer of nAl. The heat released from the pre‑ignition reaction could promote the decomposition of PVDF. The decomposition reaction of CL‑20 could be accelerated by combining with nAl and PVDF. Compared with nAl/PVDF/CL‑20 material acquired by mechanical mixing, nAl@PVDF@CL‑20 composite particles prepared by microfluidic method possess homogeneous component distribution.