scholarly journals Electric double layer and electrokinetic potential of pectic macromolecules in sugar beet

2008 ◽  
pp. 21-28
Author(s):  
Tatjana Kuljanin ◽  
Ljubinko Levic ◽  
Nevena Misljenovic ◽  
Gordana Koprivica
Keyword(s):  
Sugar Beet ◽  
Double Layer ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Colloidal Particle ◽  
Electrokinetic Potential ◽  
Shear Plane ◽  
Colloidal System ◽  
Cu Ions ◽  
Measurable Property

Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+) with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules.

Field-induced dipolar attraction between like-charged colloids

Soft Matter ◽  
2018 ◽  
Vol 14 (22) ◽  
pp. 4520-4529 ◽  
Author(s):  
Chunyu Shih ◽  
John J. Molina ◽  
Ryoichi Yamamoto
Keyword(s):  
Numerical Simulations ◽  
Electric Fields ◽  
Double Layer ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Direct Numerical Simulations ◽  
Ac Electric Fields ◽  
Charged Colloids ◽  
Anisotropic Interactions

The field induced anisotropic interactions between like-charged colloidal particles is studied using direct numerical simulations, where the polarization of the electric double layer is explicitly computed under external AC electric fields.

scholarly journals An electric double layer of colloidal particles in salt-free concentrated suspensions including non-uniform size effects and orientational ordering of water dipoles

2016 ◽  
Vol 18 (1) ◽  
pp. 234-243 ◽  
Author(s):  
Jun-Sik Sin ◽  
Hak-Chol Pak ◽  
Kwang-Il Kim ◽  
Kuk-Chol Ri ◽  
Dok-Yong Ju ◽  
...  
Keyword(s):  
Double Layer ◽  
Electric Potential ◽  
Size Effects ◽  
Relative Permittivity ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Concentrated Suspensions ◽  
Uniform Size ◽  
Orientational Ordering

Non-uniform size effects and orientational ordering of water dipoles influence the relative permittivity and electric potential in suspension.

Stability of High Polymer Latexes and Their Electrokinetic Potentials

1958 ◽  
Vol 31 (5) ◽  
pp. 1105-1141 ◽  
Author(s):  
S. S. Voyutskiĭ ◽  
R. M. Panich
Keyword(s):  
Colloidal Particles ◽  
Electrokinetic Potential ◽  
Point Of View ◽  
Boundary Line ◽  
Colloidal System ◽  
Colloidal Systems ◽  
Long Time ◽  
The Stability ◽  
Colloid Systems

Abstract The stability of colloid systems is a central problem of colloid chemistry. Therefore, many papers have been devoted to studies of coagulation and to the development of criteria of stability for colloid systems. For a long time a prevalent opinion was that the stability of colloidal particles could be explained by the fact that like charge on the particles prevents agglomeration of particles which collide due to Brownian motion. This opinion was first expressed by Hardy and later developed by Powis, Ellis and a number of other scientists. According to this point of view, electrokinetic potential (ζ potential) is the measure of stability. However, after detailed investigation of coagulation phenomena and accumulation of experimental data the correctness of this point of view became less obvious, and the statement that the electrokinetic potential is a criterion of stability of colloidal systems underwent vigorous criticism. The reasons for the measured values of electrokinetic potentials not always corresponding to the stability of certain systems are as follows: firstly, the exact determination of electrokinetic potential is work of great experimental difficulty which seems to some investigators insuperable. Some of these difficulties are (1) the necessity of performing the mocroelectrophoresis in a medium which has the same characteristics as the colloidal system under investigation, (2) the influence on electrophoresis of the simultaneously occurring electrolysis (3) the wash out of the boundary line between the solution and the colloidal system, and a number of others. In the case of microelectrophoresis, these difficulties are replaced by others, which are not less difficult to overcome.

Hydrodynamics of electrophoretic motion in an alternating electric field

1993 ◽  
Vol 246 ◽  
pp. 321-334 ◽  
Author(s):  
R. P. Sawatzky ◽  
A. J. Babchin
Keyword(s):  
Charged Particle ◽  
Electric Field ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Electrokinetic Potential ◽  
Exact Analytical Solution ◽  
Colloidal Systems ◽  
Alternating Electric Field ◽  
Electric Double Layer Thickness ◽  
Double Layer Thickness

Electrophoresis in an alternating electric field is the basis for electroacoustical measurements. These measurements provide new means of investigating the electrokinetic properties of colloidal systems. In order to relate electroacoustical signals to the charge and the size of colloidal particles, an expression is required for the dynamic electrophoretic mobility of colloidal particles in a continuous fluid. In this paper, an exact analytical solution to the problem is given for an arbitrary ratio between the particle radius and the electric double-layer thickness, in the case where the electrokinetic potential of the uniformly charged particle is small and unaffected by the alternating field.

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