Directed self-assembly of colloidal crystals by dielectrophoretic ordering.
In this Article, we report the dielectrophoretic assembly of colloidal particles and show how the kinetics of assembly and degree of ordering depend on the particle size, charge, solution ionic strength, and field strength and frequency. A special dielectrophoresis (DEP) sample cell is constructed and validated to quantitatively measure directed self-assembly via sequential light scattering and optical microscopy measurements. Our results confirm the recently established scaling for the order-disorder transition and extend it to higher scaled frequencies. The limiting scaling of the order-disorder transition and particle electrophoretic mobility are correctly predicted by the standard electrokinetic model (SEKM). In particular, the order-disorder transition line is predicted from the particle properties using a recently proposed empirical scaling law and the SEKM over an order of magnitude in particle size.
Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
Jason M
JM
McMullan
Norman J
NJ
Wagner