Metastable Intermolecular Composites Assembled With Graphene Oxide Or Graphene Quantum Dots

Metastable intermolecular composites?MICs?,also called nanostructured Energetic Materials?EMs?have attracted great attention during last two decades owing to their potential applications for both civilian and military purposes.Up to date,several protocols such as physical mixing,sol-gel processing,high-energy ball milling,and molecular self-assembling have been developed for the preparations of MICs.Among these,the self-assembly techniques are used commonly.However,it is worth pointing out that the media suitable for the MICs assembly procedure seems still limited.Graphene Oxide?GO?,owing to its unique single atomic layered structure,exhibits amazing physical/chemical properties,including large specific surface area,abundant surface oxygenic functional groups such as epoxy groups,hydroxyl and carboxylic groups and could also be dispersed in water and some organic solvents moderately.Putting together,the GO is most probably the best media candidates for MIC assembly.In the work,we report for the first time the MICs assembled using GO and GQDs as media.Moreover,the effects of preparation temperature,stoichiometric ratio of MICs,and other possible factors on the energetic performances of MICs are also studied systematically.First,the MICs assembled using Al NPs as fuel,CuO NPs as oxidizer,and GO or GQDs as media were prepared and their energetic performances are evaluated.In comparison,the as-assembled Al/GQDs/CuO MICs show unique energetic performance in contrast to the physical mixture of Al and CuO NPs.More specifically,the MICs assembled at relatively higher temperature and with proper Al:GQDs:CuO ratio of 20:1:90?in weight?exhibit overall better energetic performances,including the higher heat releasing rate and larger specific heat of 1054 J/g.It was also illustrated the specific heat amount released during the reaction can be lifted to 1302 J/g by whittling the oxide layer of the Al NPs surface,revealing that the inactive oxide layer on Al NPs should be one of the main reasons influencing the energetic performances of the MICs.Second,the preparation and energetic performances of MICs assembled using Al NPs as fuel,Fe₂O₃ NPs as oxidizer,GQDs as building blocks are also described in the work.The MICs with Al:GQDs:Fe₂O₃ratio of 20:0.5:60?in weight?exhibit overall higher heat releasing rate and with Al:GQDs:Fe₂O₃ ratio of 20:1:60?in weight?exhibit relatively larger specific heat of 1804 J/g.Analogously,the as-assembled Al/GQDs/Fe₂O₃MICs show better energetic performance than those of the physical mixture of Al and Fe₂O₃ NPs.Consequently,the work shows that the GQDs should be a useful media for MICs assembling,and can be further benifical for the preparations and applications of EMs.