Synthesis And Characterization Of CuO/Al Nanowires Thermite Film And Its Properties Controlled Via Interface Layer

The ignition temperature,reactivity,combustion performance and thermal stability of the nanothermite films can be precisely controlled by changing the monolayer thickness,the contact degree of components as well as interface layer.A combination of electrochemical anodization and magnetron sputtering was used to prepare CuO/Al nanowire thermite films.The optimal stoichiometric ratio was obtained by the thickness variation in sputtered Al layer.In order to study the impacts of the interface layer on the reactivity and combustion performance of nanothermite film,Ni and NiO were deposited on the surface of CuO nanowires by magnetron sputter and chemical bath deposition,respectively.The thicknesses of Ni and NiO can be controlled by adjusting the process parameters.Finally,a layer of Al was deposited onto the nanowires to obtain CuO@Ni/Al and CuO@NiO/Al nanowire thermite films.The thermal analysis and combustion performance tests reveal that the optimum equivalence ratio for the CuO/Al nanowire thermite film is about 1.39.Under the optimum condition,the heat release,activation energy and maximum pressure output of the CuO/Al nanowire thermite film are 2811.7J/g,252.15 k J/mol and 4.02 MPa,respectively.The effects of the Ni and NiO interface layers on the heat release performance and combustion properties of the CuO/Al nanowire thermite films are explicitly different.In this dissertation,it is explained that by increasing the thickness of Ni,it will reduce the heat release and pressure output of CuO@Ni/Al systems.When the thickness of Ni is 17 nm,the heat release,activation energy and maximum pressure output of the CuO@Ni/Al system decreases by 29.6%,36.7% and 42.3%,respectively.Al/Ni alloys were formed at the interface that resist the oxygen diffusion between CuO and Al.Morever,the addition of Ni interface layer into the CuO/Al systems provides a heat drop which not only absorbs the heat from the thermite reaction but also prevents the heat transfer.The heat release and pressure output of CuO@NiO/Al system increase at first and then decrease with increasing NiO thickness.The deposition of 25 nm NiO layer between CuO and Al has shown an increase in the heat release by 7.5% and pressure output by 23.9% and decrease in the activation energy by 36.2%.Different from Ni as interface layer,NiO can participate in thermite reaction,promote the reaction of CuO/Al and induce the solid-solid phase reaction.