title: Predicting the disorder-order transition of dielectrophoretic colloidal assembly with dielectric spectroscopy.
abstract: The dielectrophoretic assembly of colloidal suspensions into crystalline arrays is described by a master scaling that collapses the disorder-order transition as a function of field strength, frequency, and particle size. This master scaling has been verified for particle diameters ranging from 2a = 200 nm to 3 μm by light scattering (Lumsdon et al., Langmuir 2004, 20, 2108-2116; McMullan and Wagner, Langmuir 2012, 28, 4123-4130), optical laser tweezer measurements (Mittal et al., J. Chem. Phys. 2008, 129, 064513), and small-angle neutron scattering (McMullan and Wagner, Soft Matter 2010, 6, 5443-5450). In this work, we reconcile the empirical phase diagram with direct measurements of the colloid polarizability using dielectric spectroscopy. Dielectric spectroscopy confirms the origin of the order-disorder transition frequency dependence, including its quadratic scaling with particle radius, a(2), and provides an alternative method to search for optimal self-assembly conditions.
authors.affiliation: Department of Chemical and Biomolecular Engineering and Center for Molecular and Engineering Thermodynamics, University of Delaware, Newark, DE 19716, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Beltramo
authors.forename: Eric M
authors.initials: EM
authors.lastname: Furst
mesh_terms: D003102:Colloids / Q000737:chemistry*; D058266:Dielectric Spectroscopy / Q000379:methods*; D004560:Electricity; D004586:Electrophoresis / Q000379:methods*; D008962:Models, Theoretical; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry
chemical_list: D003102:Colloids; D011137:Polystyrenes