Stern potential, zeta potential and dipole moment of aerosil particles dispersed in electrolyte solutions

2007 ◽  
pp. 87-92 ◽  
Author(s):  
H. Sonntag ◽  
H. Pilgrimm
Keyword(s):  
Dipole Moment ◽  
Zeta Potential ◽  
Electrolyte Solutions ◽  
Stern Potential

The effects of electrolyte concentration, ion species and pH on the zeta potential and electrokinetic charge density of montmorillonite

Clay Minerals ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 853-861 ◽  
Author(s):  
E. E. Saka ◽  
C. Güler
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Negative Charge ◽  
Electrolyte Concentration ◽  
Great Influence ◽  
Electrolyte Solutions ◽  
Ionic Species ◽  
Positive Sign ◽  
Ion Species ◽  
Influence Of Ph

AbstractIn this study, the influence of pH, electrolyte concentration and type of ionic species (such as LiCl, NaCl, KCl, RbCl, CsCl, CaCl2, AlCl3) on the electrokinetic properties (zeta potential and electrokinetic charge density) of montmorillonite has been quantified. The zeta potential of montmorillonite particles did not change significantly with change in pH. The valencies of the ions have proven to have a great influence on the electrokinetic behaviour of the suspension. There is a gradual decrease in the zeta potential (from —24 mV to —12 mV) with increase in monovalent electrolyte concentration (from 10-4 M to 10-1 M). At any monovalent electrolyte concentration, the magnitude of the zeta potential increased with the electrolytes in the order Li+ > Na+ > K+ > Rb+ > Cs+. The zeta potential of the montmorillonite minerals in CaCl2 solutions illustrated the same behaviour as the monovalent cations. Less negative values were obtained for the CaCl2 electrolyte (∼–10 mV) due to the greater valence of the ions. A sign reversal was observed at an AlCl3 concentration of 5 x 10-4 M, and, at greater concentrations, zeta potential values had a positive sign (∼20 mV).The electrokinetic charge density of montmorillonite showed similar trends of variation in mono and divalent electrolyte solutions. Up to concentrations of ∼10-3 M, it remained practically constant at ∼0.5 x 10-3Cm-2, while for greater electrolyte concentrations the negative charge produced more negative values (–16 x 10-3Cm-2). The electrokinetic charge density of montmorillonite particles was constant at low AlCl3 concentrations, but at certain concentrations it increased rapidly and changed sign to positive.

Electrokinetics-generated pore fluid and ionic transport in an offshore calcareous soil

2003 ◽  
Vol 40 (6) ◽  
pp. 1185-1199 ◽  
Author(s):  
E Mohamedelhassan ◽  
J Q Shang
Keyword(s):  
Zeta Potential ◽  
Calcareous Soil ◽  
Fluid Transport ◽  
Calcareous Soils ◽  
Maximum Flow ◽  
Ionic Transport ◽  
Electrolyte Solutions ◽  
Pore Fluid ◽  
Zeta Potentials ◽  
Soil Pores

In this study, the electrokinetics-generated pore fluid transport in an offshore calcareous soil is investigated in three steps. The pore fluid of the soil specimen tested has a salinity equivalent to that of seawater (artificial or A-seawater). The electroosmotic flow rates are measured for the A-seawater and two stabilizing permeating solutions, i.e., 15% CaCl2 and 10% Al2(SO4)3·18H2O solutions. The results show that electroosmosis generated significant flow in the soil and can effectively transport the two permeating solutions through soil pores filled with A-seawater. The maximum flow rate is observed in the test conducted with 15% CaCl2 solution, followed by those of A-seawater and 10% Al2(SO4)3·18H2O solutions, respectively. The results also show the significant role of electromigration in transporting the cations in the permeating solutions from the anode to the cathode. In particular, it is found that the electrokinetics-generated ionic transport for calcium (Ca2+) is 6.3 times faster than that for aluminum (Al3+). The surface charge properties of the calcareous soil are studied by measuring the zeta potentials of the soil solids suspended in electrolyte solutions of various types, concentrations, and pH values. The relationship between the experimental and theoretical coefficients of electroosmotic permeability, ke, is examined based on the results from the electrokinetic experiments and the Helmholtz–Smoluchowski model. It is concluded that the effectiveness of electroosmosis in transporting water can be predicted qualitatively or semiquantitatively from the zeta potential of the soil solids suspension. The influence of pore fluid pH on the zeta potential of the soil is also investigated. The study provides important information for the use of electrokinetics to facilitate in situ artificial cementation of calcareous soils for offshore foundation applications.Key words: calcareous soil, electrokinetics, electroosmosis, electromigration, zeta potential, soil–water–electrolyte system.

Shear Thinning and Thickening of Alumina Suspensions

2010 ◽  
Vol 105-106 ◽  
pp. 833-836
Author(s):  
Xiang Yang Lu ◽  
Li Ming Zhang ◽  
Yong Huang
Keyword(s):  
Zeta Potential ◽  
Particle Surface ◽  
Shear Thickening ◽  
Shear Thinning ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Stern Potential ◽  
Thickening Behavior ◽  
Alumina Suspensions

The rheological behavior of alumina suspension stabilized with Tri-ammonia citrate (TAC) was studied. It was thought that there would form some particle clusters due to the collisions between particles caused by their relative motion in the suspension, and such particle clusters are classified as thermodynamic clusters and hydrodynamic clusters by their origin. Shear thinning is the result of decomposition of the thermodynamic clusters, while shear thickening is the result of formation of the hydrodynamic clusters. From the view of cluster-forming potential barrier, it was deemed that the viscosities of alumina suspensions at low and high shear rates are respectively determined by zeta potential and Stern potential on the particle surface, and shear thickening behavior can be suppressed with some excessive TAC.

Surface characterization of polymer foils

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Zdenka Kolská ◽  
Alena Řezníčková ◽  
Václav Švorčík
Keyword(s):  
Zeta Potential ◽  
Surface Characterization ◽  
Streaming Potential ◽  
Electrolyte Solutions ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Polymer Foils

AbstractElectrokinetic potential (zeta potential) for selected 21 polymer foils was studied. The results on zeta potential are supplemented with contact angle measurements (goniometry) and with the results on surface roughness measured by atomic force microscopy (AFM). Zeta potential was determined using two approaches: streaming current and streaming potential at pH=6.0-6.2. Two electrolyte solutions with KCl (concentrations 0.001 and 0.005 mol/dm3) and KNO3 (0.001 mol/dm3) were used in the experiments. Zeta potential was shown to depend on surface chemistry, polarity, roughness and morphology of the polymer foils.

Zeta potential study of natural- and acid-activated sepiolites in electrolyte solutions

2011 ◽  
Vol 90 (3) ◽  
pp. 785-792 ◽  
Author(s):  
Sedef Dikmen ◽  
Gulgun Yilmaz ◽  
Ertugrul Yorukogullari ◽  
Emine Korkmaz
Keyword(s):  
Zeta Potential ◽  
Electrolyte Solutions ◽  
Potential Study

Zeta potential in porous rocks in contact with monovalent and divalent electrolyte aqueous solutions

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. D303-D314 ◽  
Author(s):  
Luong Duy Thanh ◽  
Rudolf Sprik
Keyword(s):  
Zeta Potential ◽  
Streaming Potential ◽  
Shear Plane ◽  
Theoretical Models ◽  
Porous Rocks ◽  
Electrokinetic Phenomena ◽  
Reservoir Rocks ◽  
Partially Saturated ◽  
Different Types ◽  
Stern Potential

Electrokinetic phenomena are the result of a coupling between a fluid flow and an electric current flow in porous rocks. The zeta potential is an important parameter that influences the electrokinetic coupling. Most reservoir rocks are saturated or partially saturated by natural water containing various types of ions. Therefore, it is important to understand how the zeta potential and therefore the electric double layer (EDL) behave for different types of ions or electrolytes. Types of electrolytes influence the zeta potential most by affecting the surface charge — by changing the thickness of the EDL and the exact location of the shear plane. To study the dependence of the zeta potential on various electrolytes, we have carried out streaming potential measurements for consolidated rock samples saturated by monovalent and divalent electrolytes. From streaming potential coefficients, the zeta potential is obtained for different systems of electrolytes and rocks. The experimental results of silica-based rocks are then compared with theoretical models. For 1:1 or 1:2 electrolytes, a theoretical model for the zeta potential that has been available in literature is used. For 2:2 or 2:1 electrolytes, we have developed a new model to calculate the Stern potential and the zeta potential. The comparison found that the theoretical models can explain the main behavior of the zeta potential against types of electrolytes and types of silica-based rocks. The results show that the zeta potential for monovalent electrolytes is higher than that for divalent electrolytes. The zeta potential of the silica-based samples is higher than that of the nonsilica-based samples when they are saturated by the same types of electrolyte.

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