(637d) Role of Surface Metallization and Chemistry in the Self-Assembly of Metallodielectric Janus Colloids

We study the clustering via non-covalent binding of colloidal polystyrene spheres with a hemispherical coating of gold and quantify the effects of gold thickness and self-assembled monolayer chemistry on that binding. A gold layer varying from 10 nm to 100 nm in thickness was deposited on 1-micron diameter carboxylate-stabilized polystyrene spheres.  The metallic surface was functionalized with a self-assembled monolayer of varying hydrophobicity and chain length. The kinetics of self-assembly was studied in aqueous suspensions as a function of the concentration of added electrolyte. The ordered clustering of these Janus microspheres was studied using confocal laser scanning microscopy. We investigate cluster formation and specificity as a function of salt concentration varied from 1mM – 5mM and as a function of gold layer thickness. We discuss the kinetics and equilibrium structures observed in light of the variation in metal layer thickness and Janus balance as they relate to the pair potential interactions of metallodielectric Janus particles.