title: Circuit modification in electrical field flow fractionation systems generating higher resolution separation of nanoparticles.
abstract: Compared to other sub-techniques of field flow fractionation (FFF), cyclical electrical field flow fractionation (CyElFFF) is a relatively new method with many opportunities remaining for improvement. One of the most important limitations of this method is the separation of particles smaller than 100nm. For such small particles, the diffusion rate becomes very high, resulting in severe reductions in the CyElFFF separation efficiency. To address this limitation, we modified the electrical circuitry of the ElFFF system. In all earlier ElFFF reports, electrical power sources have been directly connected to the ElFFF channel electrodes, and no alteration has been made in the electrical circuitry of the system. In this work, by using discrete electrical components, such as resistors and diodes, we improved the effective electric field in the system to allow high resolution separations. By modifying the electrical circuitry of the ElFFF system, high resolution separations of 15 and 40nm gold nanoparticles were achieved. The effects of applying different frequencies, amplitudes and voltage shapes have been investigated and analyzed through experiments.
authors.affiliation: Department of Bioengineering, University of Utah, Salt lake City, UT 84112, USA. Electronic address: onurtasci@gmail.com.
authors.forename: Tonguc O
authors.initials: TO
authors.lastname: Tasci
authors.affiliation: Department of Geology and Geophysics, University of Utah, Salt lake City, UT 84112, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Johnson
authors.affiliation: Department of Geology and Geophysics, University of Utah, Salt lake City, UT 84112, USA.
authors.forename: Diego P
authors.initials: DP
authors.lastname: Fernandez
authors.affiliation: Department of Geology and Geophysics, University of Utah, Salt lake City, UT 84112, USA.
authors.forename: Eliana
authors.initials: E
authors.lastname: Manangon
authors.affiliation: Department of Mechanical Engineering, University of Utah, Salt lake City, UT 84112, USA.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Gale
mesh_terms: D004560:Electricity; D031521:Fractionation, Field Flow / Q000379:methods*; D006046:Gold; D053768:Metal Nanoparticles / Q000032:analysis*
chemical_list: D006046:Gold
keywords: Electrical field flow fractionation; Field flow fractionation; Nanoparticle characterization; Nanoparticles