Calculation of the electrophoretic mobility of a spherical colloid particle

Abstract

A new calculation of the relation between the electrophoretic mobility and the/--potential of a spherical colloid particle is presented. The model consists of a rigid, electrically insulating sphere surrounded by a Gouy-Chapman double layer. The appropriate differential equations (which account for both electrophoretic retardation and relaxation effect) have been solved without approximations on an IBM 704 computer.The theoretical assumptions and the basic equations ~re stated. A detailed account of the solutions of the equations is pub]ished elsewhere. The present paper contains the complete results. Comparison of these results with those of Overbeek ~nd of Booth shows that, %r high ~--potential ~nd 0.2 < ~a < 50, their approximations generally overestimate the relaxation effect. The application to practical cases (especially colloid particles in solutions of 1-1 electrolytes) is discussed extensively. Finally, the theoretical results are compared with experimental data published by others.

Carboxylated Ficolls: Preparation, Characterization, and Electrophoretic Behavior of Model Charged Nanospheres

“…at 70% ionization of all carboxyl groups), which implies that the mobility does not follow the increase of charge amount but becomes nonmonotonic at a critical surface charge density, as predicted by many theories. [1][2][3][4][5][6][7] The surface potential ψ 0 can be determined experimentally according to pK a -pK 0 ) 0.434eψ 0 (R)/kT (4) where K a and K 0 are the apparent and the intrinsic dissociation constants respectively, e is the electron charge, k is Boltzmann's constant, and T is absolute temperature. K a can be deduced from where pK 0 is obtained by extrapolating pK a to R ) 0.…”

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

“…The electrostatic repulsive potential ( el ) was computed using the modified HoggHealy-Fuerstenau approximation derived by Sader et al (11). For these calculations, the surface potential  0 is assumed to be equal to the measured zeta-potential, and the Debye length,  , was set to the values estimated rheologically as reported in section 3.2.1.4.…”

“…Relaxation can be neglected in the case of very small or large a, but it is significant for intermediate values, particularly at high potentials [10]. Wiersema et al [11] as well as O´Brien and White [12] developed models to account for high surface potentials and the double layer relaxation effect. For a values between 0.1 and 100 a very complex relation between electrophoretic mobility and -potential has been found.…”

Successive ionic layer deposition of Fe3O4HxMoO4nH2O composite nanolayers and their superparamagnetic properties

“…The values of the ζ potential were corrected within the approximation of the Overbeek-Booth-Wiersema model [19].…”