Flow dichroism as a reliable method to measure the hydrodynamic aspect ratio of gold nanoparticles.
Flow dichroism as a reliable method to measure the hydrodynamic aspect ratio of gold nanoparticles.
复制标题
流动二色性是测量金纳米颗粒流体动力学纵横比的可靠方法。
作者：
Naveen K. Reddy;J. Pérez‐Juste;I. Pastoriza‐Santos;P. Lang;J. Dhont;L. Liz‐Marzán;J. Vermant
颗粒形状对纳米颗粒悬浮液和纳米复合材料的光学、磁性和力学性能起着重要的控制作用。然而，表征纳米颗粒的大小、形状和相关的多分散性并不是直截了当的。电子显微镜提供了几何性质的精确测量，但样品制备可能是费力的，并且要获得统计相关的数据，许多粒子需要单独分析。此外，当颗粒悬浮在流体中时，测量它们的流体动力学特性是很重要的，因为它们决定了悬浮液的扩散和流变行为等方面。评估纳米颗粒动力学的方法，如光散射和流变光学方法，准确地提供了这些流体动力学特性，但确实需要足够的光学响应。在本工作中，对表征非球形金纳米粒子的三种不同方法进行了严格的比较，特别是考虑到这些粒子的复杂光学响应。根据其通用性来评估不同的方法，以评估大小、形状和多分散性。其中，流变光学技术是获得非球形金纳米颗粒的水动力纵横比和多分散性最可靠的方法。首先，利用取向角的演化使得多分散性的影响不那么重要。其次，外部流场的使用使粒子运动和展弦比之间的关系在数学上更加牢固，特别是对于具有相对较小展弦比的粒子。
Particle shape plays an important role in controlling the optical, magnetic, and mechanical properties of nanoparticle suspensions as well as nanocomposites. However, characterizing the size, shape, and the associated polydispersity of nanoparticles is not straightforward. Electron microscopy provides an accurate measurement of the geometric properties, but sample preparation can be laborious, and to obtain statistically relevant data many particles need to be analyzed separately. Moreover, when the particles are suspended in a fluid, it is important to measure their hydrodynamic properties, as they determine aspects such as diffusion and the rheological behavior of suspensions. Methods that evaluate the dynamics of nanoparticles such as light scattering and rheo-optical methods accurately provide these hydrodynamic properties, but do necessitate a sufficient optical response. In the present work, three different methods for characterizing nonspherical gold nanoparticles are critically compared, especially taking into account the complex optical response of these particles. The different methods are evaluated in terms of their versatility to asses size, shape, and polydispersity. Among these, the rheo-optical technique is shown to be the most reliable method to obtain hydrodynamic aspect ratio and polydispersity for nonspherical gold nanoparticles for two reasons. First, the use of the evolution of the orientation angle makes effects of polydispersity less important. Second, the use of an external flow field gives a mathematically more robust relation between particle motion and aspect ratio, especially for particles with relatively small aspect ratios.
DOI：
10.1146/annurev.bb.17.060188.002145
发表时间：
1988
期刊：
Annual review of biophysics and biophysical chemistry
影响因子：
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作者：
Elliot L. Elson
通讯作者：
Elliot L. Elson