Separation of Latex Particles According to Size by Continuous Electrophoresis

McCann, G. D.; Vanderhoff, J. W.; Strickler, Allen; Sacks, T.

doi:10.1080/03602547408068794

Cited by 17 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, McCormick has experimentally demonstrated an improved separation of silica sols, ranging from 5 to 44 nm in diameter, when the ionic strength of the buffer was decreased 4-fold [3]. Much earlier, Hannig et al [23] and McCann et al [24] showed a preparative separation of polystyrene latex microparticles in a buffer of a low ionic strength that disappeared upon elevating buffer concentration in accordance with theoretical expectation. The effects of composition and concentration of electrolyte solutions on separation of colloidal particles in CZE have also been reported by other authors [25±27].…”

Section: Resultssupporting

confidence: 56%

Capillary zone electrophoresis of sub-μm-sized particles in electrolyte solutions of various ionic strengths: Size-dependent electrophoretic migration and separation efficiency

2000

View full text Add to dashboard Cite

To gain insight into the mechanisms of size-dependent separation of microparticles in capillary zone electrophoresis (CZE), sulfated polystyrene latex microspheres of 139, 189, 268, and 381 nm radius were subjected to CZE in Tris-borate buffers of various ionic strengths ranging from 0.0003 to 0.005, at electric field strengths of 100-500 V cm(-1). Size-dependent electrophoretic migration of polystyrene particles in CZE was shown to be an explicit function of kappaR, where kappa(-1) and rare the thickness of electric double layer (which can be derived from the ionic strength of the buffer) and particle radius, respectively. Particle mobility depends on kappaR in a manner consistent with that expected from the Overbeek-Booth electrokinetic theory, though a charged hairy layer on the surface of polystyrene latex particles complicates the quantitative prediction and optimization of size-dependent separation of such particles in CZE. However, the Overbeek-Booth theory remains a useful general guide for size-dependent separation of microparticles in CZE. In accordance with it, it could be shown that, for a given pair of polystyrene particles of different sizes, there exists an ionic strength which provides the optimal separation selectivity. Peak spreading was promoted by both an increasing electric field strength and a decreasing ionic strength. When the capillary is efficiently thermostated, the electrophoretic heterogeneity of polystyrene microspheres appears to be the major contributor to peak spreading. Yet, at both elevated electric field strengths (500 V/cm) and the highest ionic strength used (0.005), thermal effects in a capillary appear to contribute significantly to peak spreading or can even dominate it.

show abstract

Section: Resultssupporting

confidence: 56%

Capillary zone electrophoresis of sub-μm-sized particles in electrolyte solutions of various ionic strengths: Size-dependent electrophoretic migration and separation efficiency

2000

View full text Add to dashboard Cite

show abstract

“…For gold nanoparticles with different hydrophilic coatings, we demonstrated that the application of the approximate analytic approach developed by Ohshima 42,43 requires for cations and anions differing largely in their electrophoretic mobility that the effective ionic drag coefficient is approximated by the ionic drag coefficient of the (strong electrolyte) counterion. 44 The conversion of electropherograms into size distribution functions after size-selective separation due to the relaxation effect was first suggested by McCann et al 45 in 1973 based on measurements made with continuous flow electrophoresis. However, CE has the additional advantage of high separation efficiency.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The conversion of electropherograms into size distribution functions after size-selective separation due to the relaxation effect was first suggested by McCann et al in 1973 based on measurements made with continuous flow electrophoresis. However, CE has the additional advantage of high separation efficiency.…”

Section: Introductionmentioning

confidence: 99%

Determination of the Exact Particle Radius Distribution for Silica Nanoparticles via Capillary Electrophoresis and Modeling the Electrophoretic Mobility with a Modified Analytic Approximation

2017

View full text Add to dashboard Cite

In this study, we use aqueous dispersions of amorphous silica nanoparticles of various sizes to investigate whether electropherograms recorded from capillary electrophoresis experiments can be converted directly into exact number-based particle radius distributions, provided that there is a relaxation effect-based size selectivity of the electrophoretic mobility and provided that the electrokinetic potential ζ of the particles can be regarded to be homogeneous over the surface of the particles, independent of the particle size. The results of this conversion procedure are compared with number-based particle radius distributions obtained from a large set of transmission electron microscopy (TEM) data. For this specific example, it is shown that the modified analytic approximation developed by Ohshima adequately describes the mobility-dependent relaxation effect and the electrophoretic mobility of the particle as a function of the reduced hydrodynamic radius and electrokinetic potential, which is a prerequisite for the presented procedure. Simultaneously, we confirmed that for the given Debye length/particle diameter ratio the electrokinetic surface charge density can be regarded to be size-invariant (including spherical geometry and planar limiting case). It is shown that the accuracy of the results of the developed method is comparable to that gained by a large set of TEM data, which is important when a precise description of the particle size distribution is needed to deduce conclusions regarding the underlying mechanism(s) of particle growth. The values obtained for the dispersion (width) of the distribution show only a small negative deviation, when compared with the TEM data (4-16%).

show abstract