Directed Self-Assembly: A Study of the E ect of Electric Fields on Silica Monolayers (thesis)

Abstract

In this thesis, we describe, analyze, and extend ionic self-assembly of monolayers (ISAM), a bottom-up nanostructure production technique designed to coat surfaces in uniform layers of charged nanoparticles. Using mean field theory, we develop cooperative sequential adsorption with evaporation (CSAE) models of the assembly process, designed to predict the particle coverage density of ISAM samples. We simulate the particle assembly process via the Monte Carlo technique, and we evaluate our CSAE models primarily by comparing them to these simulated results. Finally, aided by scanning electron microscopy, we analyze experimental ISAM samples. This experimental approach provides us with information about the time scale of assembly, as well as the relationship between our CSAE models and particle suspension concentration. Our approach considers ISAM under no external influence, as well as ISAM conducted under constant and oscillating electric fields. Assembly under electric fields represents a type of directed self-assembly of monolayers (DSAM), an emerging technique designed to control particle coverage density using an external influence.