The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Jacob H. Masliyah - One of the best experts on this subject based on the ideXlab platform.
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bitumen clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z A Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system.
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Bitumen-clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z. Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system. © 2002 Elsevier Science (USA).
Z. Xu - One of the best experts on this subject based on the ideXlab platform.
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bitumen clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z A Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system.
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Bitumen-clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z. Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system. © 2002 Elsevier Science (USA).
Z A Zhou - One of the best experts on this subject based on the ideXlab platform.
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bitumen clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z A Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system.
Z. Zhou - One of the best experts on this subject based on the ideXlab platform.
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Bitumen-clay interactions in aqueous media studied by Zeta Potential distribution measurement
Journal of Colloid and Interface Science, 2002Co-Authors: Z. Zhou, Z. Xu, Jacob H. MasliyahAbstract:A novel technique to investigate the interactions between bitumen and clays in an aqueous solution from the measurement of Zeta Potential distributions is described. For a single component suspension (i.e., clay or bitumen), a single modal Zeta Potential distribution was obtained under a given solution condition. In the case of a two-component (i.e., bitumen and clay) mixture system, the measured Zeta Potential distribution showed either one or two distribution peaks, depending on the chemical condition of the suspension and the type/amount of clays present. In the absence of added calcium ions, a mixture of bitumen emulsion and clay suspension exhibited two distinct Zeta Potential distribution peaks, corresponding to the peaks measured individually for the bitumen and clays, respectively. With the addition of 1 mM calcium ions, however, only one Zeta Potential distribution peak was obtained for the mixture of bitumen emulsion and montmorillonite clay suspension. Depending on the montmorillonite clay to bitumen ratio, the peak position in this case shifted toward the value for montmorillonite clay suspension alone. For kaolinite, the addition of 1 mM calcium ions did not cause a substantial change in the bimodal Zeta Potential distribution. The results suggest qualitatively a stronger interaction of bitumen with montmorillonite clay than with kaolinite clay, when calcium ions were present. The slime coating of montmorillonite clay on bitumen droplets in the presence of 1 mM calcium was validated. The conclusions obtained from this study further justified our mechanistic hypothesis for the observed depression of bitumen flotation by montmorillonite but not by kaolinite clay addition when calcium ions were added. This study demonstrated that Zeta Potential distribution measurement could be a powerful tool to study slime coating phenomena in a complex colloidal system. © 2002 Elsevier Science (USA).
Philippe Leroy - One of the best experts on this subject based on the ideXlab platform.
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influence of surface conductivity on the apparent Zeta Potential of calcite
Journal of Colloid and Interface Science, 2016Co-Authors: Shuai Li, Philippe Leroy, Frank Heberling, Nicolas Devau, Damien Jougnot, Christophe ChiabergeAbstract:Zeta Potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the Zeta Potential of calcite is still poorly known because of the difficulty to interpret streaming Potential experiments. The Helmholtz-Smoluchowski (HS) equation is widely used to estimate the apparent Zeta Potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming Potential. We present streaming Potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming Potential model corrects the apparent Zeta Potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the Zeta Potential of calcite, particularly when the electrolyte is diluted (ionic strength ⩽ 0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted the corrected Zeta Potential by assuming that the Zeta Potential is located at the outer Helmholtz plane, i.e. without considering a stagnant diffuse layer at the calcite-water interface. The surface conductivity of calcite crystals was inferred from electrical conductivity measurements and computed using our basic Stern model. Surface conductivity was also successfully predicted by our surface complexation model.
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influence of surface conductivity on the apparent Zeta Potential of tio2 nanoparticles
Journal of Colloid and Interface Science, 2011Co-Authors: Philippe Leroy, Christophe Tournassat, Mohamed BiziAbstract:Zeta Potential is a physico-chemical parameter of particular importance to describe ion adsorption and electrostatic interactions between charged particles. Nevertheless, this fundamental parameter is ill-constrained, because its experimental interpretation is complex, particularly for very small and charged TiO2 nanoparticles. The excess of electrical charge at the interface is responsible for surface conductance, which can significantly lower the electrophoretic measurements, and hence the apparent Zeta Potential. Consequently, the intrinsic Zeta Potential can have a larger amplitude, even in the case of simple 1:1 electrolytes like NaCl and KCl. Surface conductance of TiO2 nanoparticles immersed in a NaCl solution is estimated using a surface complexation model, and this parameter and particle size are incorporated into Henry's model in order to determine a constrained value of the Zeta Potential from electrophoresis. Interior conductivity of the agglomerates is calculated using a differential self-consistent model. The amplitude of estimated Zeta Potential is greater than that derived from the von Smoluchowski equation and corresponds to the electric Potential at the Outer Helmholtz Plane calculated by our surface complexation model. Consequently, the shear plane may be located close to the OHP, contradicting the assumption of the presence of a stagnant diffuse layer at the TiO2/water interface.