Synthetic routes to monodisperse gold nanoparticles stabilized by different-length alkanethiols

Abstract

My thesis explored three different synthesis routes toward obtaining monodisperse clutches of well-ordered nanoparticles stabilized by various alkanethiols. The first two synthesis methods were based on a two-phase system employing first tetraoctylammonium bromide (TOAB) as a phase transfer catalyst and then didodecyldimethylammonium bromide (DDAB). Though these methods approximated what could be considered monodisperse nanoparticles ([sigma]< 5%) by reaching distributions of a [sigma]~-19% for TOAB and [sigma]- 13% for DDAB at their best, they were easily surpassed by the degree of monodispersity achieved by a one-phase method. This one-phase method, which does not use inverse micelles to control the reduction process, was able to reach distribution levels where o<10%. More specifically, the method proved robust enough to synthesize monodisperse, well-ordered nanoparticles with the following alkanethiols: octanethiol, nonanethiol, decanethiol, dodecanethiol, pentadecanethiol; and the following distributions: [sigma]~7%, [sigma]~9%, -[sigma]~7%, [sigma]~4%, and ~ [sigma]8%, respectively.