Superhydrophobic Fluorine‐Containing Protective Coating to Endow Al Nanoparticles with Long‐Term Storage Stability and Self‐Activation Reaction Capability

Abstract

Abstract The stability of aluminum (Al) nanoparticles (ANPs) is a key issue that can determine the energetic properties of Al‐based energetic materials. In this study, a surface functionalization approach is employed, using the chemical adsorption and auto polymerization effects of the 1H, 1H, 2H, 2H‐perfluorodecyltriethoxysilane (FAS‐17), to set up a highly stable barrier coating to water and further endow ANPs with long‐term storage stability and self‐activation reaction capability. The FAS‐17‐modified ANPs (AFNPs) with a superhydrophobic surface show their excellent stability in air and unique strengths in corrosion resistance to water by enhancing diffusion resistance of O 2 and preventing the hydration reaction. In terms of energetic performances, compared to the two‐step slow oxidation of ANPs, the heat‐release rate of AFNPs is significantly enhanced, resulting in a drastic oxidation process profiting from the surface reaction between the FAS‐17 and alumina (Al 2 O 3 ) layer. More importantly, the ignition and combustion properties of AFNPs are also greatly improved, which can undergo self‐propagation combustion with a fairly high energy output even after stored in water. At last, the possible mechanisms of oxidation resistance and self‐activation reaction capacities are also proposed.