Preparation And Reactivity Of Fluoro-Nanothermite

The most widely used fuel in a nanothermite system are aluminum nanoparticles?n-Al?.The inevitable passivation shell outside the n-Al nanoparticles during the production,storage and combustion will retarded reaction properties of nanothermite.Meanwhile,nanothermite grains with high particle loading suffer from problems such as agglomeration of the nanoparticles and insufficient mechanical properties,the application of the nanothermite in the energetic material is virtually impossible.Firstly,empolying FeF₃ as oxidizer,n-Al as fuel,we designed the brand new n-Al/FeF₃ nanothermite.The thermal and combustion behavior of the n-Al/FeF₃ nanothermite was investigated.n-Al/FeF₃ nanothermite?410??has lower initial reaction temperature than n-Al/n-Fe₂O₃ nanothermite?5290C?;n-Al/FeF₃ nanothermite?reaction equation Al + FeF₃ =AlF₃ + Fe?demonstrated more complete reaction to n-Al/n-Fe₂O₃ nanothermite?reaction equation 2A1 + 9Fe₂O₃ = Al2O3 + 6Fe304?;n-Al/FeF₃ nanothermite(1824 J g^-1)has higher heat of reaction than n-Al/n-Fe₂O₃ nanothermite(216 J g^-1);n-Al/FeF₃ nanothermite has faster burning rate when compared to n-Al/Fe₂O₃ nanothermite.Secondly,the thermal reaction process of some nanothermite?n-Al/n-CuO,n-Al/n-Fe₂O₃,n-Al/n-Co₃O₄ and n-Al/n-NiO?/fluoropolymer?PVDF and PTFE?nanocomposite was investigated.The traditional view of fluoropolymer in thermite reaction,as an oxidizer,seems o be inadequate.In our investigation,it is observed that fluoropolymer is acting as both oxidizer and reducer during the thermal decomposition process of the nanocomposites.The carbon and hydrogen in fluoropolymer were oxidized by the nano metal oxide,generating CO₂ and H₂O;while the aluminum was oxidized to AlF₃ by fluoropolymer.We also investigated the combustion behavior of n-Al/n-CuO/fluoropolymer?PVDF and PTFE?nanocomposite.The result show that adding small amount of fluoropolymer into the nanothermite can improved the maximum pressure and pressurization rate of the pressure cell test.Lastly,electrospray method was used to deploy a laminate structure of alternating layers of n-Al/n-CuO thermites in a PVDF reactive binder,with a spacer layer of PVDF.We also used electrospinning/electrospray approach to create a reactive polymer fiber reinforced composite with n-Al/n-CuO nanothermite in a PVDF reactive binder.Both the reactive and mechanical properties of the laminate and fiber reinforced films significantly outperformed the single layer structure and the non-nanofiber structure with the same material composition,respectively.