Nanocomposites and nanomaterials

Assemblies of binary gold nanoparticles with reconfigurable structure and optical properties

Szustakiewicz, P.1, Kowalska, N,1 Bagiński, M,1 Lewandowski, W.1
1Faculty of Chemistry, University of Warsaw, Warsaw, Poland

Metallic nanoparticles exhibiting localized surface plasmon resonance have found applications in various fields like medicine, optics or catalysis. By changing the distances of neighboring nanoparticles, we can control their plasmonic response through plasmon coupling. Such systems can be divided into static, where structure remains constant after the preparation or dynamic, where the structure changes upon external stimuli. A very promising route to structural switchability is liquid-crystalline (LC) functionalization of nanoparticles.

Figure 1. Graphical representation of temperature-induced structural change of gold nanoparticles system.
In our previous work [1][2], we were able to prepare various gold/silver LC-functionalized nanoparticles systems with temperature-dependent structure. Importantly, the structural changes were accompanied by the shift of plasmonic peak. Currently, we are exploring the idea of preparing systems with more than one type of LC-functionalized nanoparticle, e.g. two different sizes/shapes of nanoparticles in one system. This translates into possibility of better control over optical properties, as we can expect greater change in plasmonic response during the thermally induced structure change. These kinds of properties are on high demand in areas like metamaterials, waveguiding and photonics.. 

1.	W. Lewandowski, et al., Nanoscale, 8, 2656–2663 (2016).
2.	W. Lewandowski, et al., Nat. Commun., 6, 6590 (2015).