Stephane Badaire1, Vikram Singh2, Cecile Cottin-Bizonne2, and Abraham D. Stroock3. (1) School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, NY 14853, (2) Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, NY 14853, (3) School of Chemical and Biomolecular Engineering, 360 Olin Hall, Cornell Univeristy, Ithaca, NY 14583
The generation of "chemistry of colloids" to form ordered structures from colloidal building blocks requires the development of large set of tunable interactions. We have developed a lithographic route to forming monodisperse samples of colloids with well-defined, non-spherical shapes and controlled colloidal properties. In this talk, we will present studies performed with dispersions of these particles, with a focus on the role of three distinct properties in defining the strength and selectivity of particle-particle interactions: the global shape of particles, the local roughness of surfaces on particles, and the molecular weight of neutral surfactants adsorbed on the surface of particles. We will illustrate these effects qualitatively in the structure of state diagrams formed by varying ionic strength and concentration of non-adsorbing depletants. We will also present quantitative evaluations of the energy of particle-particle interactions based on measured statistics of assembled structures. We will conclude with a discussion of opportunities for using these distinct characteristics synergistically to control assembly processes.