Construction And Characterization Of Nano-Porous Silicon/Lanthanide Nitrate Composite Energetic Materials

Porous silicon has been used to construct new composite energetic materials with high energy density due to its large specific surface area and high chemical activity.However,there are still some deficiencies in the research of preparation methods and explosive properties of porous silicon composite energetic materials.In this paper,N-type monocrystalline silicon of single-sided polished,back-plated gold,crystal orientation<100>,resistivity 2~4?·cm and thickness 325±25?m were used as raw material,and porous silicon were prepared by single-cell constant current electrochemi-cal anodization.A new electrolyte system was developed to replace the traditional system.Porous silicon/lanthanide nitrate composite energetic materials were constructed and their explosive properties were compared.The main research contents are as follows:(1)The performances of porous silicon and its composite energetic materials prepared by four solvents were compared by weight-loss method and explosion spectroscopy.It was found that the porosity of the porous silicon prepared by DMAC system has a porosity of up to 45%,and a maximum film thickness of 285?m.Under the same preparation conditions,the explosive performances of the energetic materials prepared by this system were the strongest.The variation of the surface morphology,film thickness,porosity and explosive properties with anodizing conditions were studied by single factor experiments.(2)The explosive properties of six porous silicon/lanthanide nitrate composite energetic materials were compared by orthogonal experiments,and the optimal preparation conditions were determined.The experimental results showed that the the porous silicon/lanthanum nitrate composites had the weakest explosive performance,and the explosive properties of porous silicon/samarium nitrate composites were the strongest.The explosive properties of six energetic materials were the strongest under the conditions of current density of 50 mA/cm~2,oxidation time of 35 min and V(HF):V(DMAC)=4:1,5:1.(3)The physic-chemical properties of porous silicon were investigated when the explosive properties of six energetic composite materials were the strongest.The main results were as follows:When the volume ratio of HF to DMAC was 4:1,the average film thickness and porosity of porous silicon were 153.4?m and 37.70%,respectively;when the volume ratio was 5:1,the average film thickness and porosity of porous silicon were 157.5?m and 35.03%,respectively;and the load molar ratio of oxidants of each composite material was 0.0142,0.0160,0.0165,0.0175,0.0192,0.0169,respectively.(4)The explosive properties of six composite energetic materials under the optimum preparation conditions were analyzed.The experimental results were consistent with the conclusions of orthogonal experiments.The explosion color temperature of porous silicon/samarium nitrate composites was 2506 K.The explosion process is intense and rapid,and the heat release is as high as 983.44 J/g.