Colloids streaming potential

The well-known DLVO theory of coUoid stabiUty (10) attributes the state of flocculation to the balance between the van der Waals attractive forces and the repulsive electric double-layer forces at the Hquid—soHd interface. The potential at the double layer, called the zeta potential, is measured indirectly by electrophoretic mobiUty or streaming potential. The bridging flocculation by which polymer molecules are adsorbed on more than one particle results from charge effects, van der Waals forces, or hydrogen bonding (see Colloids). 

The electrokinetic processes can actually be observed only when one of the phases is highly disperse (i.e., with electrolyte in the fine capillaries of a porous solid in the cases of electroosmosis and streaming potentials), with finely divided particles in the cases of electrophoresis and sedimentation potentials (we are concerned here with degrees of dispersion where the particles retain the properties of an individual phase, not of particles molecularly dispersed, such as individual molecules or ions). These processes are of great importance in particular for colloidal systems. 

In part II of the present report the nature and molecular characteristics of asphaltene and wax deposits from petroleum crudes are discussed. The field experiences with asphaltene and wax deposition and their related problems are discussed in part III. In order to predict the phenomena of asphaltene deposition one has to consider the use of the molecular thermodynamics of fluid phase equilibria and the theory of colloidal suspensions. In part IV of this report predictive approaches of the behavior of reservoir fluids and asphaltene depositions are reviewed from a fundamental point of view. This includes correlation and prediction of the effects of temperature, pressure, composition and flow characteristics of the miscible gas and crude on (i) Onset of asphaltene deposition (ii) Mechanism of asphaltene flocculation. The in situ precipitation and flocculation of asphaltene is expected to be quite different from the controlled laboratory experiments. This is primarily due to the multiphase flow through the reservoir porous media, streaming potential effects in pipes and conduits, and the interactions of the precipitates and the other in situ material presnet. In part V of the present report the conclusions are stated and the requirements for the development of successful predictive models for the asphaltene deposition and flocculation are discussed. 

Nystrom, M., M. Lindstrom and E. Matthiasson. 1989. Streaming potential as a tool in the characterization of ultrafiltration membranes. Colloids di Surfaces 36 297-312. 

In their study of the effects of hydrolyzable cations on electro kinetic phenomena (see Problem 4), James and Healy compared the electrophoretic behavior of colloidal silica with the streaming potential through a silica capillary. In both sets of experiments the solution was 10-3 M KN03 and 10 4 M Co(N03)2. The following results were obtained ... 

Reppert, P.M., Morgan, F.D., Lesmes, D. and Jouniaux, L. (2001) Frequency-dependent streaming potentials, Journal of Colloid Interface Sci 234, 194-203, 93-1... 

Wischerhoff E, Laschewsky A (1999) Polyelectrolyte adsorption onto planar surfaces a study by streaming potential and ellipsometry measurements. Colloids Surf A Physicochem Eng Aspects 159 491... 

The work of Larson et al. (62) represented the first detailed study to show agreement between AFM-derived diffuse layer potentials and ((-potentials obtained from traditional electrokinetic techniques. The AFM experimental data was satisfactorily fitted to the theory of McCormack et al. (46). The fitting parameters used, silica and alumina zeta-potentials, were independently determined for the same surfaces used in the AFM study using electrophoretic and streaming-potential measurements, respectively. This same system was later used by another research group (63). Hartley and coworkers 63 also compared dissimilar surface interactions with electrokinetic measurements, namely between a silica probe interacting with a polylysine coated mica flat (see Section III.B.). It is also possible to conduct measurements between a colloid probe and a metal or semiconductor surface whose electrochemical properties are controlled by the experimenter 164-66). In Ref. 64 Raiteri et al. studied the interactions between... 

For well-dispersed colloid systems, particle electrophoresis has been the classic method of characterization with respect to electrostatic interactions. However, outside the colloidal realm, i.e., in the rest of the known world, the measurement of other electrokinetic phenomena must be used to characterize surfaces in this respect. The term electrokinetic refers to a number of effects induced by externally applied forces at a charged interface. These effects include electrophoresis, streaming potential, and electro-osmosis. 

To characterize a surface electrokinetically involves the measurement of one of the above electrokinetic effects. With disperse colloidal systems it is practical to measure the particle electrophoretic mobility (induced particle velocity per unit applied electric field strength). However, for a nondisperse system one must measure either an induced streaming potential or an electro-osmosis fluid flow about the surface. 

Abbreviations titr. titration el. phor. = electrophoresis el. cap. = electric capacitance str. pot. = streaming potential stab. = colloid stability comm. = commercial product chromatogr. = chromatographic 1mm. = immersion susp. eff. = suspension effect, prec. = precipitated. 

Electrokinetic mobilities can be measured by direct observation of the particle movement by use of a microscope or of the boundary between suspension and clear electrolyte separated from the suspension by centrifugation (moving boundary method). When electrolyte is forced through a fixed bed, e.g., of carbon fibers, a potential builds up between the ends of the bed. This streaming potential can also be used for the measurement of -potentials. Details of these methods are described in textbooks of colloid chemistry. 

An introduction to electrokinetic phenomena can be found in [240] and in handbooks of colloid chemistry. The choice of method and instrument suitable for the character of a sample is key to successful electrokinetic measurements. In principle, all techniques and all instruments should produce the same potential and the same IEP in a system of interest. A few multi-instrument studies have been published. For example, [241] reports lEPs obtained by streaming potential and by electrophoresis (using a commercial apparatus). A multi-instrument electrokinetic study of alumina in O.OIM NitNO, is reported in [242]. The IEP was also relatively consistent with different solid-to-liquid ratios. Glass capillaries with inner sides coated with spherical nanosize hematite particles showed an IEP at pH = 5, while the IEP of the original hematite obtained by electrophoresis was at pH 9.3 [243]. 

Zembala, M. and Adamczyk. Z., Measurements of streaming potential for mica covered by colloid particles, Langmuir, 16, 1593, 2000. 

Moritz, T. et al.. Investigation of ceramic membrane materials by streaming potential measurements. Colloids Surf. A, 195, 25, 2001. 

Somasundaran, P. and KuUcami, R.D., A new streaming potential apparatus and study of temperature effects using it, 7. Colloid Interf. Sci., 45, 591, 1973. 

Szymczyk, A., Fievet, P., and Foissy, A., Electrokinetic characterizaton of porous plugs from streaming potential coupled with electrical resistance measurements, J. Colloid Interf. Sci., 255, 323, 2002. 

Zembala, M., Adamczyk, Z., and Warszynski, P, Influence of adsorbed particles on streaming potential of mica, Colloids Surf. A, 195, 3, 2001. 

Minor, M. et al.. Streaming potentials and conductivities of porous silica plugs, Colloids Surf A, 142, 165, 1998. 

Ricq, L. et al., Use of electrophoretic mobility and streaming potential measurements to characterize electrokinetic properties of ultrafiltration and microfiltration membranes, Colloids Surf. A, 138, 301, 1998. 

Sun, Y. and Spencer, H.G., Effects of calcium ions on the streaming potentials of zirconium hydrous oxide-polyacrylate foimed-in-place membranes, J. Colloid Interf. Sci., 126, 361, 1988. 

Carlson, K. and Hall, M.. Streaming potential measurements performed on silicate and calcium aluminate glass microspheres, Colloids Surf. A, 325, 101. 2008. 

Bismarck, A., Kumru, M.E., and Springer, J., Characterization of several polymer surfaces by streaming potential and wetting measurements Some reflections on acid-base interactions, J. Colloid Interf. Sci., 217, 377, 1999. 

Roessler, S. et al.. Characterization of oxide layers on Ti6A14V and titanium by streaming potential and streaming current measurements, Colloids Surf. B, 26, 387, 2002. 

Pressure gradient Filtration Particle oscillations Streaming current and potential Colloid vibration potential... 

Particle charge plays a major role on the stabilization of colloidal systems. Especially when nanoparticles are stabilized by an adsorption layer of polyelectrolytes, zeta potential measurements are very useful. The stabilization of the nanoparticles results from a combination of ionic and steric contributions. The zeta potential can be detected by means of electro-osmosis, electrophoresis, streaming potential, and sedimentation potential measmements. The potential drop across the mobile part of electric donble layer can be determined experimentally, whenever one phase is made... 

R. J. Kurtz, E. Findl, A. B. Kurtz, and L. C. Stormo, Turbulent Flow Streaming Potentials in Large Bore Tubing, J. Colloid Interface Sci. 57, 28 (1976). 

Norde W, Rouwendal E (1990) Streaming potential measurements as a tool to study protein adsorption-kinetics. J Colloid Interface Sd 139(1) 169-176... 

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