a team of researchers at the u.s. department of energy lawrence livermore national laboratory (livermore, calif.) have developed a new, lightweight, silver nanowire aerogel that has advanced electrical and thermal properties that make it useful in practical electronics applications, including fuel cells, energy storage, medical devices, and more.
a new ultralight silver nanowire aerogel developed by lawrence livermore national laboratory scientist is so light that it could lay on a fragile rosebud without the flower wilting.
(lawrence livermore national laboratory)
a report from livermore lab explained that metal foams, also knowns as porous metals, have been developed to be lightweight, have increased surface area, high electrical conductivity, and low thermal conductivity.
“but conventional methods of creating these foams require demanding manufacturing conditions including high temperature, high pressure and/or strict oxygen exclusion. in some cases, they are not scalable for mass production,” the report continued.
“using nanowires as building blocks, the fabrication of silver aerogels doesn't have these limitations. in addition, the new silver aerogels have tunable densities, controlled pore structures, improved electrical conductivity and mechanical properties, making it attractive for practical applications.”
the new fabrication method uses silver nanowires assembled at the livermore lab that are low-density and able to conform to unique geometries.
“silver nanowire building blocks were prepared by polyol synthesis and purified by selective precipitation,” the article said. “silver aerogels were produced by freeze-casting nanowire aqueous suspensions followed by thermal sintering to weld the nanowire junctions.”
the research as recently published in nano letters (and will be featured on the cover of the december issue). the abstract read:
“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/cm3 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.”