SmallTalks "Understanding the role of adsorbed CTAB in anisotropic nanostructure growth"

Abstract 

Surfactants, such as cetyltrimethylammonium bromide (CTAB), are commonly employed to control structure and increase stability during wet-chemical synthesis of nanostructures. The functionality of surfactants is dictated by their phase diagrams, which are often complex in aqueous solution. During nanostructure growth the complexity increases even further due to the presence of surfaces. Improved control over nanostructure shape and size requires understanding the functionality—and thus structure—of adsorbed surfactants, as this directly affects the growth. Phase diagrams are, however, notoriously difficult to probe. To investigate the role of surfactants during nanostructure growth, we consider CTAB phases, which have been suggested as key drivers for anisotropic nanoparticle growth. Prior findings were, however, based on single CTAB surface densities. To elucidate the role of CTAB in this context, we use atomistic simulations to develop an understanding of the CTAB surface phase diagram from a modeling perspective.