Reactive molecular dynamics simulation of thermal decomposition behavior of HNIW/SWCNTs composite system

The thermal decomposition of the HNIW/SWCNTs composite system was investigated using ReaxFF molecular dynamics simulations to clarify the interfacial interactions between SWCNTs and HNIW. Results show that the introduction of SWCNTs significantly delayed the initial N–NO 2 bond cleavage and the degradation of the HNIW cage. The structural evolution of SWCNTs at high temperatures exhibited strong temperature dependence. At 1500 and 2000 K, the tubular structure remained largely intact. At 2500 K, localized necking and the accumulation of non-six-membered ring defects appeared. At 3000 and 3500 K, extensive bending and breakage occurred in SWCNTs, although portions of the six-membered ring framework were still preserved. Compared to the pure HNIW system, the formation and consumption of the main intermediates (HONO, N 2 O, and HNO 2 ) in the HNIW/SWCNTs composite system were noticeably delayed, while the accumulation rate of CO increased. Although the final yields of N 2 , H 2 O, and CO 2 were comparable to those in pure HNIW, the formation rate of N 2 decreased, and the time required to reach equilibrium increased. In addition, increasing the density of the HNIW/SWCNTs system promoted the thermal decomposition reaction.