Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853, USA.
Nat Commun. 2017 Mar 16;8:14778. doi: 10.1038/ncomms14778.
Gold nanostructured materials exhibit important size- and shape-dependent properties that enable a wide variety of applications in photocatalysis, nanoelectronics and phototherapy. Here we show the use of superfast dynamic compression to synthesize extended gold nanostructures, such as nanorods, nanowires and nanosheets, with nanosecond coalescence times. Using a pulsed power generator, we ramp compress spherical gold nanoparticle arrays to pressures of tens of GPa, demonstrating pressure-driven assembly beyond the quasi-static regime of the diamond anvil cell. Our dynamic magnetic ramp compression approach produces smooth, shockless (that is, isentropic) one-dimensional loading with low-temperature states suitable for nanostructure synthesis. Transmission electron microscopy clearly establishes that various gold architectures are formed through compressive mesoscale coalescences of spherical gold nanoparticles, which is further confirmed by in-situ synchrotron X-ray studies and large-scale simulation. This nanofabrication approach applies magnetically driven uniaxial ramp compression to mimic established embossing and imprinting processes, but at ultra-short (nanosecond) timescales.
金纳米结构材料表现出重要的尺寸和形状依赖性特性，使其在光催化、纳米电子学和光疗等领域具有广泛的应用。在这里，我们展示了使用超快动态压缩来合成具有纳秒聚结时间的扩展金纳米结构，如纳米棒、纳米线和纳米片。我们使用脉冲电源发生器将球形金纳米颗粒阵列升压至数十 GPa 的压力，证明了压力驱动的组装超越了金刚石压腔的准静态范围。我们的动态磁斜坡压缩方法产生了平滑、无冲击（即等熵）的一维加载，具有适合纳米结构合成的低温状态。透射电子显微镜清楚地表明，各种金结构是通过球形金纳米颗粒的压缩介观聚结形成的，这进一步通过原位同步辐射 X 射线研究和大规模模拟得到证实。这种纳米制造方法应用磁驱动的单轴斜坡压缩来模拟已建立的压印和压印工艺，但在超短（纳秒）时间尺度内。
