Speaker: Rachael Skye (Dshemuschadse Group)

Title: Killing the magic: the effects of particle softness and dispersity on nanocluster assembly

Abstract: Colloidal nanoclusters are used as catalysts, for tunable light absorption and emission, or to enhance imaging via plasmonic resonance. Many of their properties are highly tunable with cluster geometry and size, but the process of assembling these clusters is also inherently heterogenous: it is, in general, extremely difficult to synthesize large amounts of similar particles to target specific properties. Therefore, designing processes to target monodispersity is an ongoing goal of experimental synthesis. One such avenue is the so-called “magic-size” effect, in which a specific geometry and number of particles yields a cluster that is notably stable compared to clusters with similar sizes. Here, we compare known cluster structures based on the interactions that drive their formation in order to elucidate the basis of the magic-size effect in different systems. Using coarse-grained molecular dynamics simulations, we model the assembly of small clusters in a range of particle systems, examining the effects of size dispersity and compressibility or softness across different cluster types. Our findings will guide synthesis of colloidal clusters by allowing for targeted process development.