| Recently micro/nano energetic materials have attracted intensive interests from the researchers for its improved performances compared to their bulk or micro counterparts such as high energy releasing rate, short ignition delay time. The energetic thin film including the Al/metal or metal oxide composite film possessed high energy output, however, it is lack of the function of producing gas and it reveals high ignition temperature. Therefore, in this study the method of "in-situ chemical reaction" was employed to introduce the organic energetic material zinc picrates into the thin film firstly, leading the formation of membrane possessing the function of producing gas and high energy out put simultaneously, which will improve the diversity of function for energetic devices and show great significance. The detail process was as follows:The picric acid solution was used to add onto the surface of ZnO nanowires film which was prepared by the hydrothermal method, producing organic energetic material zinc picrates on the ZnO nanowire and resulting in the formation of ZnO/zinc picrates composite thin film. The energetic thin film was characterized by NMR, XRD, SEM and TG-DSC and the test results was compared to that of zinc picrates powder. Meanwhile, the thermal decomposition reaction kinetics of zinc picrates powder was investigated and explored by TG-DSC-QMS-FTIR coupling method and the non-linear multivariate regression. The results were obtained as follows:1) ZnO nanowires on the substrate FTO generated by the method of hydrothermal synthesis showed good crystalline(JC-PDF Card NO.36-1451) and preferred growing along the (002) direction, whose surface exhibited good uniform of the nanowires in the large range. The results of 1H-NMR indicated that the substance produced by the complete reaction of picric acid with ZnO nanowires possessed symmetrical structure which is Zn(pic)2 consistent with that of zinc picrates powder. The diffraction peaks coming from the zinc picrates thin film have moved high zone about 0.35-0.40°compared to that for zinc picrates powder, which was caused by the difference of chemical reaction environment and the intensity of 002 plane (ZnO nanowire) was reduced significantly from the XRD pattern of zinc picrates energetic thin film, indicating that the ZnO was consumed for the in-situ chemical reaction.2) The results of TG-DSC carried on the ZnO/zinc picrates thin film suggests that the thermal decomposition reaction started from the 260℃lower than that of reaction onset temperature of Al/metal or Al/metal oxide(about above 400℃), in which zinc picrates released a large mount of gas and heat equal to 2491.18J·g-1 higher than that (1020J·g-1, 1085J·g-1) obtained for the Al/NiO and Al/CuO based on nano energetic materials in previous reports. Therefore, it is can be concluded that zinc picrate thin film exhibits the properties of high energy output and the function of producing gas。3) From the TG-DSC curves the thermal decomposition process of zinc picrates can be divided into two stages:The first stage was the weight loss caused by crystal water's loss while the second stage was considered as the decomposition of zinc picrates itself. The calculation result obtained by the non-linear multivariate regression indicates that there are four stages in the whole decomposition process of zinc picrates and the kinetic model A■D based on the mechanism function of f(a)= (1-a)n can describe the decomposition process well. |
PDF Full Text Request