Kinetics and equilibrium distribution of colloidal assembly under an alternating electric field and correlation to degree of perfection of colloidal crystals

The kinetics and equilibrium distribution of colloidal particles near an electrode surface subjected to an alternating electric field are investigated by varying the frequency, field strength, and salt concentration. The variation of the aggregation rate constant as well as the order/crystallinity of the lattice can be correlated to the variation of the equilibrium interparticle separation r(eq) within the frequency window for the two-dimensional (213) assembly. Particle size, ionic concentration, and field strength also affect the mean equilibrium distance between neighboring particles, thus establishing that r(eq) can be used as a new criterion to examine the degree of perfection of a 2D colloidal assembly and the self-assembly process of colloidal particles. The understanding gained in this study may be found useful in the design of self-assembled templates using colloidal particles.