空心微球结构Au/Ag合金泡沫块体的制备

Preparation of monolithic foamed Au/Ag alloy with hollow microspheres

将平均晶粒尺寸为4.6nm的金粒子通过静电作用粘附于聚苯乙烯(PS)微球表面用于化学镀,化学镀金后PS表面的金沉积层几乎达到完全包覆,厚度70～90nm;在Au/PS表面进行化学镀银,沉积的银颗粒堆积紧密,颗粒大小较先前沉积的金颗粒大,镀覆层厚度增厚至200～400nm;模板去除后,获得了完全自支撑的Au40Ag60空心微球结构的圆柱状泡沫材料。制备的金银合金泡沫由直径约10μm的空心球壳组成,圆柱体直径约5mm,密度约1.2g/cm3。

The polystyrene（PS） microspheres were coated by gold colloid with an average grain size of 4.6 nm by the elec- trostatic effect, and then electroless plated with gold silver consecutively. The deposited gold layer was 70 to 90 nm thick, almost coating the PS spheres completely. The silver particles deposited subsequently were compact, and larger than the previously de posited gold particles, forming a 200 to 400 nm-thick layer on the surface of each Au/PS microsphere. The self-supported hollow- sphere Au40 Ag60 alloy was then obtained after the template being removed. Finally, the columniform foamed Au-Ag alloy, 5 mm in diameter, 1.2 g/cm^3 in density, was obtained with the hollow spheres of 10 μm diameter after heat treatment.