多孔硅/高氯酸钠复合材料的合成与爆炸特性研究

Study on synthesis and explosion properties of porous silicon/NaClO_4 composite

本文采用电化学阳极氧化法制备多孔硅,考察不同氧化条件下多孔硅孔隙率及膜厚的变化情况,研究电化学阳极氧化工艺条件、高氯酸钠溶液浓度以及贮存方法等因素对多孔硅复合材料爆炸反应的影响。结果表明,多孔硅孔隙率随电流密度增大而增大,当电流达到50mA·cm^(-2)以上时略有降低,孔隙率随氧化时间增大而先增大后减小,且氧化时间为30min时最大,孔隙率随氢氟酸浓度增大反而减小;多孔硅膜厚随时间增大而增大。SEM分析表明,多孔硅表面产生裂缝,内部形成硅柱。在电流密度小、氧化时间短的条件下形成的多孔硅复合材料不易爆炸,当NaClO4甲醇溶液质量浓度大于0.098g·mL^(-1)时发生强烈爆炸,将多孔硅复合材料用乙醇浸泡是最为理想的贮存方法。

Porous silicon is prepared by electrochemical oxidization method. The porosity and thickness of porous silicon prepared by different conditions as well as the influence of prepared conditions, concentration of sodium perchlorate solution and storage method on the explosive phenomena are researched in this paper. The results show that the porosity of porous silicon increase at the earlier stage, and decrease at the latter stage with the increase of current density and etching time; when current density is 50 mA·cm^（-2） and etching time is 30 min, porosity reached the maximum; increasing the concentration of hydrofluoric acid, the porosity will decrease; longer etching time would lead to thicker film depth. SEM analysis shows that porous silicon cracks on surface and forms silicon column in its internal. Porous silicon composite cannot explode prepared by small current density and short etching time; when the mass concentration of sodium perchlorate solution is higher than 98 g·L^（-1）, the explosion phenomena are the most obvious; the best storage method of porous silicon composite is dipping in the absolute ethanol.