Developing multicolour light scattering rigs to understand their utility for determining nano-aggregate morphology.

本课题旨在从不同共振条件下的光散射中提取新的信息。光散射（静态和动态）提供了关于溶液中纳米颗粒大小和形状的信息。然而，迄今为止，大多数系统都是使用单色激光测量光散射的。当对散射有强烈的光谱响应时，这可能是一个问题，这是等离子体系统的情况。金、银、铜或铝的金属纳米结构由于能够支持拴在其表面的局部和传播等离子体的能力而显示出与光的强耦合。特别是，等离子体组件之间的间隙设置了偶极子-偶极子耦合，控制了可以被困在它们之间的光的共振颜色。增强的光场导致强烈的可见着色（共振光被吸收或散射）以及缝隙内分子的拉曼散射（SERS）的巨大增强。我将探索可以可靠地将光捕获到各种结构中的系统，特别是在这个项目中，CB分子如何将Au纳米颗粒（NPs）结合成聚集体。这些CB:AuNP聚集体随时间增长，NPs之间有0.9nm的间隙，产生红移散射和消光共振。目标有三个：建立一个能够在不同波长下进行静态/动态散射的DLS系统，对系统进行校准，并了解可以获得哪些新信息，以及研究CB:Au聚合系统，并提取有关该过程的新信息。该博士与国家物理实验室共同指导。

This project to extract new information from light scattering in different resonance conditions. Light scattering (both static and dynamic) gives information about the size and shape of nanoparticles in solution. However most systems to date have measured light scattering using monochromatic lasers. This can be a problem when there is a strong spectral response to the scattering, which is the case for plasmonic systems.Metallic nanostructures of Au, Ag, Cu, or Al display strong coupling to light due to their ability to support localised and propagating plasmons tethered to their surface. In particular, the gap between plasmonic components sets the dipole-dipole coupling which controls the resonant colours of light which can be trapped in between them. The enhanced optical fields lead to strong visible colouration (as resonant light is absorbed or scattered) as well as enormous enhancements in the Raman scattering from molecules within the gap (SERS). I will explore systems where light can be reliably trapped into various structures, and in particular for this project how CB molecules can bind Au nanoparticles (NPs) into aggregates. These CB:AuNP aggregates grow in time, with 0.9nm gaps between the NPs, producing red-shifting scattering and extinction resonances. The goal is threefold: to build a DLS system capable of static/dynamic scattering at different wavelengths, to calibrate the system, and understand what new information can be gained, and to study the aggregating CB:Au system, and extract new information about the process. This PhD is jointly supervised with NPL.