Characterization of 2D colloid aggregations created by optically induced electrohydrodynamics. Issue 15 (3rd July 2015)

• Record Type: Journal Article
• Authors: Work, Andrew H.; Williams, Stuart J.; Lapizco‐Encinas, B. H.; Hayes, M. A.
• Is Part Of: Electrophoresis. Volume 36:Issue 15(2015)
• Page Start: 1674
• Page End: 1680
• Publication Date: 2015-07-03
• Subjects: Electrophoresis -- Periodicals; Electrophoresis -- Periodicals; 541.372
• DOI: 10.1002/elps.201500111
• Languages: English
• ISSNs: 0173-0835

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Rapid electrokinetic patterning (REP) is a technique for creating self‐assembled monolayers (SAMs) of spherical particles in a liquid medium, and dynamically controlling them though the simultaneous application of an electric field and optically induced temperature gradients. Previous work has investigated and characterized REP axisymmetric aggregations generated from a focus laser within a uniform electric field; work herein characterizes line‐shaped particle assemblies derived from the application of a linearly scanned laser. The resulting aggregations of spherical polystyrene particles (1 μm) suspended in low‐conductivity aqueous potassium chloride solution (KCl, 2.5 mS/m) resembled elliptical‐shaped crystalline geometries. The mean particle‐to‐particle spacing within the aggregation remained greater than 1.5 diameters for experiments herein (6.5 V_rms, 30 kHz) due to dipole–dipole repulsive forces. Interparticle spacing demonstrated a linear relationship (1.6–2.1 μm) with increasing scanning lengths (up to 83 μm), decreased from 1.9 to 1.7 μm with increasing scanning frequency (0.38–16 Hz) for a 53 μm scan length, and decreased from 2.0 to 1.6 μm with increasing laser power (11.9–18.8 mW) for a 59 μm, 16 Hz laser scan.</p> </abstract>