Effect of Carbon Nanotubes Geometry on the Sensing Response to Nitroglycerine Migration in Double Base Propellants

ABSTRACT In recent years, component migration and interface failure during propellant aging have attracted increasing attention, yet effective methods for dynamic performance monitoring remain limited. In this study, three carbon nanotube (CNTs)‐based sensing coating layers were fabricated, differing exclusively in CNTs aspect ratio, to enable nondestructive and quantitative monitoring of nitroglycerin (NG) migration in double‐base propellants. A systematic investigation was further conducted to explore the influence of the CNTs aspect ratio on the sensing performance related to NG migration. The coating layers were adhered onto the surfaces of double‐base propellants, followed by a controlled 71°C accelerated aging test. Results demonstrate that the intrinsic electrical conductivity of the coating layers increases with CNTs aspect ratio, reaching a maximum of 8.64 × 10 −5 Ω −1 ∙cm −1 . During aging, the electrical conductivity of all three coatings exhibits an exponential relationship with the experimentally determined NG migration amount. Notably, the coating layer with high‐aspect‐ratio CNTs presents superior conductivity and sensing response characteristics. Specifically, the sensing sensitivity is optimal at 16.73, and the average deviation between the NG migration amounts calculated from thermogravimetric analysis (TGA) measurements and the fitting equation is minimized at 7.29%. By adjusting the aspect ratio of CNTs, the conductive network structure of the sensing layer is optimized, thereby providing a materials science foundation for developing nondestructive evaluation of interfacial integrity in solid propellants based on nano‐sensing technology.