(216u) Electric Field Induced Self-Assembly of Colloidal Particles | AIChE

(216u) Electric Field Induced Self-Assembly of Colloidal Particles

Authors 

Shah, A. A. - Presenter, University of Michigan
Solomon, M. J., University of Michigan
Ganesan, M., University of Michigan
Jocz, J., University of Michigan
Ferrar, J. A., University of Michigan, Ann Arbor


Electric Field Induced Self-Assembly of Colloidal Particles

Aayush A Shah1, Mahesh Ganesan2, Jennifer Jocz2, Joseph A. Ferrar2 and Michael J. Solomon1, 2

1 Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI

2 Chemical Engineering, University of Michigan, Ann Arbor, Ann Arbor, MI

e-mail: aayushs@umich.edu

We report the use of an applied electric field to produce crystalline order in micron and sub-micron sized Brownian colloidal particles. Colloidal suspensions, because of their slow Brownian dynamics, undergo equilibrium self-assembly only on long time scales.  Application of an electric field significantly accelerates the kinetics of assembly. We analyze our results in terms of the underlying electrokinetics of the system, and connect our results to equilibrium self-assembly theory. We subsequently assemble colloidal rod shaped particles using the electric field assembly method, and report the formation of a body centered tetragonal (BCT) structure. We use this newly developed method to reversibly assemble sub-micron sized colloidal particles into crystals that show reflective color. We use light scattering, light microscopy and well as spectrophotometry to analyze the reflective color generated using this method.