Molecular phenomena in colloidal nanostructure synthesis

We review our recent studies of molecular phenomena that can affect the shapes of colloidal nanocrystals grown in solution-phase syntheses. We first present an overview of our first-principles studies with density functional theory aimed at understanding the workings of polymeric structure-directing agents (SDAs). We demonstrate that polyvinylpyrrolidone (PVP), a successful SDA for producing {100}-faceted Ag nanostrutures, possesses selective binding to Ag(100) at the segment level and it is also sufficiently stiff to achieve the correlated binding of neighbouring chain segments. In contrast, polyethylene oxide, which is not so successful, has weaker segmental selectivity and is not as stiff as PVP. We also review our studies of how solvent can influence the growth of anisotropic nanocrystals by directing nanocrystal aggregation.