Li Yuelin, Jiang Zhang, Lin Xiao-Min, Wen Haidan, Walko Donald A, Deshmukh Sanket A, Subbaraman Ram, Sankaranarayanan Subramanian K R S, Gray Stephen K, Ho Phay
Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL 60439.
Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL 60439.
Sci Rep. 2015 Jan 30;5:8146. doi: 10.1038/srep08146.
Many potential industrial, medical, and environmental applications of metal nanorods rely on the physics and resultant kinetics and dynamics of the interaction of these particles with light. We report a surprising kinetics transition in the global melting of femtosecond laser-driven gold nanorod aqueous colloidal suspension. At low laser intensity, the melting exhibits a stretched exponential kinetics, which abruptly transforms into a compressed exponential kinetics when the laser intensity is raised. It is found the relative formation and reduction rate of intermediate shapes play a key role in the transition. Supported by both molecular dynamics simulations and a kinetic model, the behavior is traced back to the persistent heterogeneous nature of the shape dependence of the energy uptake, dissipation and melting of individual nanoparticles. These results could have significant implications for various applications such as water purification and electrolytes for energy storage that involve heat transport between metal nanorod ensembles and surrounding solvents.
金属纳米棒在许多潜在的工业、医学和环境应用中，都依赖于这些粒子与光相互作用的物理过程以及由此产生的动力学和动态过程。我们报道了飞秒激光驱动的金纳米棒水胶体悬浮液整体熔化过程中一个惊人的动力学转变。在低激光强度下，熔化呈现出拉伸指数动力学，当激光强度提高时，它会突然转变为压缩指数动力学。研究发现，中间形状的相对形成和还原速率在这种转变中起关键作用。在分子动力学模拟和动力学模型的支持下，这种行为可追溯到单个纳米粒子能量吸收、耗散和熔化的形状依赖性所具有的持续非均匀性质。这些结果可能对各种应用产生重大影响，例如涉及金属纳米棒集合体与周围溶剂之间热传递的水净化和储能电解质等应用。
