Study On Preparation Of Core-shell Structured Thermites Applied To Energetic Ink For Inkjet Printing

In this paper, core-shell structured Al/Cu2(NO3)(OH)3 and Al/CuO, which could react at 270℃, were synthesized by promoted sol-gel method. Energetic inks, which were suitable for inkjet printing, were prepared based on the two core-shell structured materials. The inkjet printing characteristics of energetic inks and ignition performances of inkjet printing direct write chargings were also studied. The main research work and conclusions are as follows.Firstly, the effect of aging time on preparation of nano-CuO by sol-gel method was studied. The result showed that aging time had little effect on crystal form and average crystal particle size of CuO but affected preferential growth of CuO crystal particle on different crystal surface and agglomeration degree of nano-CuO. Core-shell structure of Al/CuO prepared from sol-gel method did not form completely. Core-shell structured Al/A12Cu could be found in experiments using PEG-2000, PEG-400, and Tween-80 as the surface modifiers. In the experiment using sodium dodecyl sulfate as suface modifier, the sample would deflagrate when the calcination temperature was rasied to 270℃. XRD and SEM results showed the uncalcined sample was core-shell structured Al/Cu2(NO3)(OH)3. Maximum quantity of heat and complete core-shell structure of Al/Cu2(NO3)(OH)3 were observed when molar ration of Al and Cu2(NO3)(OH)3 was 2:1. Calcined product of Al/Cu2(NO3)(OH)3 at 240℃ was core-shell structured Al/CuO.Secondly, the core-shell structured Al/Cu2(NO3)(OH)3 and Al/CuO were used to prepare the energetic inks and the characteristics of the energetic inks were also be investigated. The results showed that the uniformity and continuity of Al/Cu2(NO3)(OH)3 ink was better than that of Al/CuO ink.Thirdly, direct write-chargings of the two types of energetic ink were prepared by using inkjet printing devices and their ignition properties under conditions of Cr metallic bridge, heating platform and pulse laser were studied. The results showed that Al/Cu2(NO3)(OH)3 direct write-charging could be ignited by Cr metallic bridge. Al/CuO direct write-charging would burn intensely when the temperature of heating platform was raised to 400℃. Pulse laser could not ignite Al/Cu2(NO3)(OH)3 direct write-charging but could ignite Al/CuO direct write-charging.