Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Nano Lett. 2017 Dec 13;17(12):7171-7176. doi: 10.1021/acs.nanolett.7b02790. Epub 2017 Sep 13.
Low-density metal foams have many potential applications in electronics, energy storage, catalytic supports, fuel cells, sensors, and medical devices. Here, we report a new method for fabricating ultralight, conductive silver aerogel monoliths with predictable densities using silver nanowires. Silver nanowire building blocks were prepared by polyol synthesis and purified by selective precipitation. Silver aerogels were produced by freeze-casting nanowire aqueous suspensions followed by thermal sintering to weld the nanowire junctions. As-prepared silver aerogels have unique anisotropic microporous structures, with density precisely controlled by the nanowire concentration, down to 4.8 mg/cm and an electrical conductivity up to 51 000 S/m. Mechanical studies show that silver nanowire aerogels exhibit "elastic stiffening" behavior with a Young's modulus up to 16 800 Pa.
低密度金属泡沫在电子、储能、催化支持、燃料电池、传感器和医疗器械等领域有许多潜在的应用。在这里，我们报告了一种使用银纳米线制造超轻、导电银气凝胶整体的新方法，其密度可预测。银纳米线的构建块是通过多元醇合成制备的，并通过选择性沉淀进行纯化。银气凝胶是通过冷冻铸造纳米线水悬浮液，然后进行热烧结来焊接纳米线连接点来制备的。所制备的银气凝胶具有独特的各向异性微孔结构，其密度可以通过纳米线浓度精确控制，低至 4.8mg/cm3，电导率高达 51000 S/m。机械研究表明，银纳米线气凝胶表现出“弹性硬化”行为，杨氏模量高达 16800 Pa。
