Study on the thermal decomposition mechanism of graphene oxide functionalized with triaminoguanidine (GO-TAG) by molecular reactive dynamics and experiments

Abstract

Graphene oxide (GO) has a catalytic effect on the thermal decomposition of energetic materials above the melting point. To further enhance the catalytic activity of GO, it has been functionalized with the high nitrogen ligand triaminoguanidine (TAG). However, theoretical studies on the reactivity of functionalized GO (e.g., GO-TAG) have not been carried out. Therefore, the thermal decomposition of each TAG, GO and GO-TAG is studied by molecular dynamic simulations using a reactive force-field (ReaxFF) with experimental verification, and the results are reported herein. The results show that the GO nanolayer has a tendency to aggregate into a large carbon cluster during its degradation. The main decomposition products of TAG are NH 3 , N 2 and H 2 . For GO-TAG, the main decomposition products are H 2 O, NH 3 , N 2 and H 2 . GO has a significant acceleration effect on the decomposition process of TAG by decreasing the decomposition temperature of TAG. This phenomenon is in agreement with the experimental results.The initial decomposition of TAG is mainly caused by hydrogen transfer in the molecule. The edge carbon atoms of GO promote the decomposition of TAG molecules and reduce the decomposition activation energy of TAG by 15.4 kJ mol À1 . Therefore, TAG will quickly decompose due to the catalytic effect of GO. This process produces a "new" GO that catalyzes the decomposition of components such as TAG. At the same time, many free radicals (HN 2 , H 2 N and free H) are generated during the decomposition of TAG to catalyze the decomposition of other components, which in turn, enhance the catalytic capability of GO. † Electronic supplementary information (ESI) available. See

Thermostable Energetic Coordination Polymers Based on Functionalized GO and Their Catalytic Effects on the Decomposition of AP and RDX

“…Yan’s research group has reported interesting research activities by integrating and attaching various transition metal ions bridging units. , They produced a number of complexes such as GO–T–M–HCl and GO–T–M–HNO 3 . The resulting GO-based composites EMs exhibited higher thermal stability and higher heat release, where the stabilization effect is due to heat dissipation and enhanced intramolecular interaction of GO with the ligands . It has been revealed that the use of T·HNO 3 as a replacement for T·HCl provided higher thermostable compounds with better thermal features. , The results showed that the hybrid ECP catalysts can enhance the initial decomposition temperature and change the thermolysis mechanism of RDX and HMX through introducing different types of metal ions. , The detailed effect of nanoadditives, especially GO-based energetic catalysts, on thermolysis products and reaction pathways of AP are well investigated as well .…”

“…The resulting GO-based composites EMs exhibited higher thermal stability and higher heat release, 21 where the stabilization effect is due to heat dissipation and enhanced intramolecular interaction of GO with the ligands. 22 It has been revealed that the use of T•HNO 3 as a replacement for T•HCl provided higher thermostable compounds with better thermal features. 7,12 The results showed that the hybrid ECP catalysts can enhance the initial decomposition temperature and change the thermolysis mechanism of RDX and HMX through introducing different types of metal ions.…”

Superior quality chemically reduced graphene oxide for high performance EMI shielding materials

“…The weight losses are due to water vapor evolution and the thermal decomposition of unstable oxygen-containing functional groups, such as hydroxyl, carbonyl, and alkoxy groups at the RGO's edges to produce CO, CO 2 , and H 2 O. 48,49 As the temperature increases, the remaining oxygen-containing groups ( e.g. , epoxy) start to evolve releasing more CO and CO 2 gases.…”

“…7 indicates that the RGOL and RGOB, respectively, have 40% and 23% weight loss at 200 C. The weight losses are due to water vapor evolution and the thermal decomposition of unstable oxygen-containing functional groups, such as hydroxyl, carbonyl, and alkoxy groups at the RGO's edges to produce CO, CO 2 , and H 2 O. 48,49 As the temperature increases, the remaining oxygen-containing groups (e.g., epoxy) start to evolve releasing more CO and CO 2 gases. This process creates distortions in the graphitic layer structure creating new structural defects in RGO layers.…”

Preparation, Characterization and Application of Nano-Graphene-Based Energetic Materials

“…It can be inferred from the increase in activation energy that GO has a passivation In order to evaluate the effect of GO on the thermal decomposition of 4,4 -azo-1,2, 4-triazole. Fu Xiaolong et al [40] studied the thermal decomposition behavior of GO, 4,4 -azo-1,2,4-triazole (ATRZ) and GO-4,4 -azo-1,2,4-triazole complexes using molecular dynamics simulation of the ReaxFF reaction field, as shown in Figure 12. The results showed that the addition of GO increased the decomposition activation energy of 4,4azo-1,2,4-triazole.…”