Rheological Properties of Dense Silica Suspensions

1992 ◽  
Vol 289 ◽  
Author(s):  
J. Chappuis ◽  
D. Guinot ◽  
P. Leture
Keyword(s):  
Rheological Properties ◽  
Silica Particles ◽  
Point Of Zero Charge ◽  
Concentrated Suspensions ◽  
Zero Charge ◽  
Ph Conditions ◽  
Silica Suspensions

AbstractThe rheological properties and microstructure of concentrated suspensions of silica particles in water have been studied. Two typical pH conditions, the effect of the addition of CaCl2 and different mixing procedures have been investigated. When CaCl2 is added, the suspensions become very thick only if the pH is far from the point of zero charge.

scholarly journals Applicability of the Linearized Poisson-Boltzmann Theory to Contact Angle problems and Application to the Carbon Dioxide-Brine-Solid Systems

2021 ◽  
Author(s):  
Mumuni Amadu ◽  
Adango Midanoye
Keyword(s):  
Carbon Dioxide ◽  
Contact Angle ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Low Ph ◽  
Point Of Zero Charge ◽  
Zero Charge ◽  
Poisson Boltzmann ◽  
Ph Conditions

Abstract In colloidal science and bioelectrostatics, the linear Poisson Boltzmann Equation (LPBE) has been used extensively for the calculation of potential and surface charge density. Its fundamental assumption rests on the premises of low surface potential. In the geological sequestration of carbon dioxide in saline aquifers, very low pH conditions coupled with adsorption induced reduction of surface charge density result in low pH conditions that fit into the LPB theory. In this work, the Gouy-Chapman model of the electrical double layer has been employed in addition to the LPBE theory to develop a contact angle model that is a second-degree polynomial in pH. Our model contains the point of zero charge pH of solid surface. To render the model applicable to heterogeneous surfaces, we have further developed a model for the effective value of the point of zero charge pH. The point of zero charge pH model when integrated into our model enabled us to determine the point of zero charge pH of sandstone, quartz and mica using literature based experimental data. In this regard, a literature based thermodynamic model was used to calculate carbon dioxide solubility and pH of aqueous solution. Values of point of zero charge pH determined in this paper agree with reported ones. The novelty of our work stems from the fact that we have used the LPB theory in the context of interfacial science completely different from the classical approach, where the focus is on interparticle electrostatics involving colloidal stabilization.

Electrokinetic Research on the Dispersion Behavior of Nano-Ceria Particles in Concentrated Suspensions

2015 ◽  
Vol 645-646 ◽  
pp. 394-399
Author(s):  
Wei Gao ◽  
Qi Long Wei ◽  
Ling Ding ◽  
Xiao Yuan Li ◽  
Chao Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Concentrated Suspensions ◽  
Tem Analysis ◽  
Concentrated Suspension ◽  
Original Solution ◽  
Multi Scale ◽  
Scale Method ◽  
Dispersion Behavior ◽  
Significant Difference

A multi-scale method was developed, which utilized intrinsic relationships among zeta potential of particles, rheological properties of suspensions and particle size distribution (PSD), to analyze dispersion behavior of nanoparticles in concentrated suspensions. It was found that PSD of a kind of nanoceria particles by dynamic light scattering (DLS) method in solution A with concentration 5 wt% accorded well with that by direct TEM analysis, which meant the particles had been dispersed well. However, there had a significant difference when the concentration was increased to 20 wt%. When particles concentration increased from 5 wt% to 20 wt%, zeta potential in solution A changed from-150 mV to-100 mV, while zeta potential in solution B changed from-35mV to-45 mV. Variations of zeta potential of particles accorded well with rheological properties of suspensions too, from phenomenological models. When the suspensions composed by solution A and the nanoparticles with concentration about 20 wt% was diluted with its original solution to 5 wt%, the PSD of nanoceria could be measured indirectly, which accorded well with both that of a suspension prepared directly with near concentration and that from TEM images. Then a method to measure PSD of nanoparticles in concentrated suspension was brought forward.

scholarly journals Determination of Point of Zero Charge (PZC) of Concrete Particles Adsorbents

2021 ◽  
Vol 1184 (1) ◽  
pp. 012004
Author(s):  
Ebtehal A. Al-Maliky ◽  
Hatem A. Gzar ◽  
Mohammed G. Al-Azawy
Keyword(s):  
Point Of Zero Charge ◽  
Zero Charge
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