The Preparation Of Nano-energetic Porous Silicon And Investigation On Its Activity Protection

By using the double-cell electrochemical etching method,porous silicon(PS)was prepared with P-type monocrystalline silicon as the raw material,and the optimum preparation conditions for loading oxidants were determined.Filling oxidant in the PS sample with three methods separately,vacuum filling under differential pressure,ultrasonic oscillation filling and dripping method by three drops of oxidizing agent,to analyse the effects of the PS preparation conditions and the oxidant filling methods on the ignition performance of the prepared Nano-energetic materials;as well,using high-speed photography to compare the combustion processes of the samples under different preparation conditions.Using methacrylate as the row material for the hydrosilylation of prepared PS sample,then comparing the reactivity of the samples before and after the reactions.The research results are as follows:(1)Under certain condition of corrosion,the effect of time is mainly about the corrosion depth and the mass of PS;and the effect of current density is mainly reflected in the pore size and porosity.Under the conditions of 30 min corrosion time and 90 mA·cm-2 current density,the PS layer has good porous morphology and stable structure,with a thickness of about 70 μm,porosity about 80%.(2)Vacuum filling under differential pressure works best among three oxidant filling methods,ultrasonic oscillation filling follows and dripping method works worst.In addition,compared to the ultrasonic oscillation method,the vacuum differential pressure method can fill the high porosity samples,which has wider range of application and better filling effect.Under the condition of 45 corrosion min and 90 mA·cm-2 current density,the prepared PS energetic material with oxidant/fuel(O/F)mole ratio of 0.44.High-speed photography shows that the sample produce a violent ignition performance,forming a flame with the size about 4 cm for continuous 13ms.(3)Using methacrylate for the hydrosilylation of PS has certain degree of effect on maintaining activity.The results of thermal analysis and accelerating oxidation experiment show that the samples after modification still have a certain ignition ability and that is well-maintained.After accelerated oxidation,the sample’s ignition performance is better than unmodified samples under the same conditions.