模板法制备多孔核/壳结构的Fe_2O_3/Al纳米铝热薄膜

Preparation of Porous Core/Shell Structure Fe_2O_3/Al Nanothermite Membrane by Template Method

通过聚苯乙烯(PS)胶晶球模板法制备出三维有序大孔(3DOM)α-Fe2O3薄膜骨架,再利用磁控溅射将Al沉积到3DOMα-Fe2O3骨架上得到核/壳结构的Fe2O3/Al纳米铝热复合薄膜。扫描电镜(SEM)测试结果表明:纳米Al均匀地附着在α-Fe2O3骨架表面,骨架孔结构由原先的近圆形转变为Al沉积后的类菱形,孔壁的厚度从32 nm增加到100 nm;采用X射线能谱(EDS)对Fe2O3/Al纳米铝热薄膜的元素含量进行了分析;由差示扫描量热法(DSC)分析显示铝热薄膜在490℃开始反应,经历固–固和固–液两个反应阶段,总放热量达到1374.7 J/g;使用激光点火器对铝热薄膜进行点火,薄膜飞溅出火花并伴有明亮刺眼的亮光,整个发火时间达2.6 ms,显示其能被点火并发生自蔓延反应,可作为一种理想的点火材料。

A three-dimensionally ordered macroporous（3DOM） α-Fe2O3 membrane was prepared by inversing poly- styrene（PS） spheres colloidal crystal template, and nano aluminum was then introduced into the 3DOM α-Fe2O3 skeleton using magnetron sputtering method. Scanning electron microscope（SEM） images show that nano A1 coats on surface of α-Fe2O3 skeleton uniformly, and pore structure converts into a kind of diamond from previously sub- orbicular after aluminizing with wall thickness increasing from 32 nm to 100 nm. Simultaneously, elemental analy- sis of the membrane is investigated via energy dispersive spectrum（EDS）. Differential scanning calorimety（DSC） results indicate that onset temperature of the Fe2O3/A1 nanothermite membrane is 490℃, and thermite reaction be- tween A1 and Fe203 can be divided into solid-solid reaction and liquid-solid reaction. The total heat release is 1374.7 J/g. Ignition performance of the energetic membrane is investigated by laser ignition test. Sparks spatter outward with dazzling light can be observed for 2.6 ms, demonstrating that Fe203/A1 nanothermite membrane can be ignited normally.