Surface-Hydrophobic Al@COFs Core-Shell structured Composites: A class of efficient high-energy fuels

Aluminum powder is a metal fuel with numerous advantages, but it is susceptible to oxidation, which poses challenges for both ignition and combustion efficiency. Addressing these issues in the application of Al powder is crucial for enhancing the specific impulse of rockets and other related applications. By employing the concept of preparing composite materials and combining multiple materials, it is possible to enhance the stability of long-term storage of Al powder and improve ignition and combustion efficiency. This paper delves into the innovative synthesis and application of Al@COFs-based core–shell structured composites filled with AP to enhance stability, reduce ignition delay time, and improve the combustion efficiency of Al powder. To further enhance the water repellency of the composites, fluoroalkylsilanes were used to coat the Al@COFs@AP composites. The fluoroalkylsilane coating not only improves the oxidation resistance of Al but also introduces F, which disrupts the alumina shell of Al during combustion, generating AlF3 and increasing the heat of combustion. The findings presented in this paper will pave the way for the development of advanced aluminum-based materials with enhanced combustion characteristics and broadens the application areas of COFs.