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

本项目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)提供有关溶液中纳米颗粒的大小和形状的信息。然而，到目前为止，大多数系统都使用单色激光测量光散射。当对散射有强烈的光谱响应时，这可能是一个问题，等离子体系统就是这种情况。金、银、铜或铝的金属纳米结构由于能够支持束缚在其表面的局域和传播的等离子激元而显示出对光的强烈耦合。具体地说，等离子体成分之间的间隙设置了偶极-偶极耦合，它控制着可以被困在它们之间的光的共振颜色。增强的光场导致了强烈的可见光着色(因为共振光被吸收或散射)，以及来自能隙内分子的拉曼散射(SERS)的巨大增强。我将探索光可以可靠地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)结合到聚集体中。这些CB：AUNP聚集体随着时间的推移而生长，纳米粒子之间有0.9 nm的间距，产生红移散射和消光共振。我们的目标有三个：建立一个能够在不同波长进行静态/动态散射的DLS系统，对该系统进行校准，了解可以获得哪些新信息，以及研究Cb：Au聚集体系统，并提取关于该过程的新信息。这一博士学位是与NPL共同监督的。

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.