Wright Cameron, Hartland Gregory V
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA; email:
Annu Rev Phys Chem. 2025 Apr;76(1):57-81. doi: 10.1146/annurev-physchem-082423-032529. Epub 2025 Jan 22.
Ultrafast excitation of nanoparticles can excite the acoustic vibrational modes of the structure that correlate with the expansion coordinates. These modes are frequently seen in transient absorption experiments on metal nanoparticle samples and occasionally for semiconductors. The aim of this review is to give an overview of the physical chemistry of nanostructure acoustic vibrations. The issues discussed include the excitation mechanism, how to calculate the mode frequencies using continuum mechanics, and the factors that control vibrational damping. Recent results that demonstrate that the high frequencies inherent to the acoustic modes of nanomaterials trigger a viscoelastic response in surrounding liquids are also discussed, as well as vibrational coupling between nanostructures and mode hybridization within the nanostructures. Mode hybridization provides a way of manipulating the lifetimes of the acoustic modes, which is potentially useful for applications such as mass sensing.
纳米颗粒的超快激发能够激发与膨胀坐标相关的结构的声学振动模式。这些模式在金属纳米颗粒样品的瞬态吸收实验中经常出现，在半导体中偶尔也会出现。本综述的目的是概述纳米结构声学振动的物理化学。讨论的问题包括激发机制、如何使用连续介质力学计算模式频率以及控制振动阻尼的因素。还讨论了最近的研究结果，这些结果表明纳米材料声学模式固有的高频会在周围液体中引发粘弹性响应，以及纳米结构之间的振动耦合和纳米结构内的模式杂化。模式杂化提供了一种操纵声学模式寿命的方法，这对于诸如质量传感等应用可能是有用的。
