Zeta potential determination

Figure 11. Potential energy diagram for two spherical carbon black particles of radius 0.2 ym with Debye lengths and zeta potentials determined for 0.2% and 0.8% solutions of OLOA-1200 in odorless kerosene.

The numerical solution for the surface potential as a function of pH is compared in Fig. 7, for various NaCI concentrations, with the experimental results provided by Li and Somasundaran [32], The potentials — ]i,s = — ]i(0) and — tyd= — t)t(t/E) are plotted as functions of distance, since the zeta potential determined by electrophoresis is not defined at the surface, but at an unknown location, the plane of slip . The magnitude of <-s is always larger than that of i >d, since the potential decays with the distance. The value dE=4 A, which is provided by the dependence of the surface tension of water on the NaCI concentration at high ionic strengths was employed. For the equilibrium constant, the value K ou= () 10 M, which is consistent with the experimental data for pH values between 3 and 6, was selected. A reasonable agreement with the data (which have a rather large error) was obtained by selecting A=5.0X 1016 sites/m2 and W1 = 0.5kT. 

Thompson, R.G., Practical zeta potential determination using electrophoretic light scattering, Am. Lab., 24, 48, 1992. 

Brookhaven 90 Plus sub-micron particle size instrument is a dual-angle instrument with measurements at 15° and 90° to generate size distributions in the 10 nm to 1 pm size range together with zeta potential determinations. 

FIG. 24 Relationship between the surface chemistry and the electrochemistry of commercial and chemically pretreated carbon blacks (a) correlation between the concentration of acidic functional groups (determined by titrations) and zeta potential (determined by electrophoresis) (b) conelation between zeta potential and the slurry pH. (Adapted from Ref. 629.)... 

The commercial systems for zeta-potential determination using these electro-acoustic effects are typified by the AcoustoSizer 8000 (Matek Applied Sciences) consisting of five main components (Fig. 5). The synthesizer produces a continuous sinusoidal voltage which feeds into the gated amplifier. This creates a sinusoidal voltage pulse across the cell which contains the dispersion. The resulting ESA sound waves are... 

Liposome Size, Size Distribution and Zeta Potential Determination... 

The manufacturer s software automatically adjusts the Laser attenuation and measnrement position. For each size and zeta potential determination, 3 measurements consisting of 6 sub runs with a duration of 10 s are averaged. 

The zeta potential determines the rate of gelation. If the charge is high, panicles effectively repel one another and avoid contact. If it is low, then thermal motion leads to collision and coalescence. These rates are highest at the isoelectronic point, where the zeta potential is zero. 

Starting with the basic concept of the electrokinetic potential of colloidal particles, the so-called zeta potential, i.e., the electrokinetic potential at the shear plane, the most important well-established methods of zeta potential determination are discussed separately. Taking into account the peculiarities of kaolin particles, the relevance of these methods for characterizing kaolin particles in the absence and the presence of polyelectrolytes are outlined here. Thereby a mixed stabilization by oppositely charged polyelectrolytes is discussed in more detail. 

Finally, the different methods of zeta potential determination are discussed with regard to their relevance to characterize polyelectrolyte-kaolin interactions. 

Colloids Electrically charged SDI and zeta potential determine fouling... 

Particle size distribntion and zeta potential determined for one of the DPUR from Table 6.1 are shown in Figures 6.10 and 6.11, respectively. TEM photographs of the particles of the same dispersion are shown in Figure 6.12. 

Generally, for a given solid-liquid system at a given temperature, the zeta potential is considered as a constant, this is because the nature of the material, its surface charge, and the nature and the concentration of the electrolyte determine the electrokinetic potential. However, early studies foxmd that zeta potential determined from Eq. 9 depends on the size of the capillary tubes for the same solid material (the capillary wall) and the... 

While some literature reports of zeta potential determinations for BaS04 systems exist, many of the reported results are problematic for one reason or another 36-47), Several reports involve experiments where ionic strength and pH were not adequately controlled, and few measurements were obtained under conditions of practical interest. 

The study of pH effect has been accomplished by some investigators. Some of them find a linear variation with pH, while others reported a plateau at some pH values [30]. Therefore we studied zeta potential of polymers at constant pH, only for isoelectric point determination we provided pH dependence. Also the effect of temperature should not be neglected, e.g. the -potential of silica increases approximately 1.75% per 1°C [30]. It is therefore important to preserve the constant temperature during zeta potential determination. 

Figure 11. Zeta potential determined by SurPASS of pristine (pristine) and modified (A) PET and (B) PTFE. The polymer foils were plasma treafed (plasma), plasma treated and grafted with (i) thiols (biphenyldithiol-BPD, cysteamine-CYST and mercaptoethanol-ME) and then (ii) grafted with Au nanoobjects (nanoparticles-AuNP and nanorods-AuNR).

Luxbacher T, Buksek H, Petrinic 1, Pusic T (2009) Zeta potential determination of flat solid surfaces using a SurPASS electrokinetic analyser. Tekstil 58 393-400. 

Buksek H, Luxbacher T, Petrinic I (2010) Zeta potential determination of Polymeric materials using two differently designed measuring cells of an electrokinetic analyser. Acta Chim. Slov. 57 700-706. 

Generally, latex-modified mortar and concrete provide a good workability over conventional cement mortar and concrete. This is mairdy interpreted in terms of improved consistency due to the ball bearing action of polymer particles and entrained air and the dispersing effect of surfactants in the latexes. Tateyashiki, et al.f 1 proved by zeta-potential determination and cryo-scanning electron microscopy that the improved consistency or fluidity is due to the ball bearing action of the polymer particles among cement particles. 

The layer of counterions surrounding a charged particle is called the diffuse double layer and the concentration of counterions in the diffuse double layer is a function of the distance from the particle surface. When a charged particle moves with respect to the surrounding liquid, that is, electrophoresis, there is a plane of shear between the two phases and the electric potential at the plane of shear is called the zeta potential, f. This is the experimentally measured quantity computed from electrokinetic motion of particles. However, even if the zeta potential is not exactly the surface potential, o it is the value used for surface potential in calculations of electrostatic stabilization in the DLVO theory. Because the zeta potential determines the net interparticle forces in electrostatically stabilized systems... 

Electroacousitc Spectral Analysis - Zeta Potential Determination and Sizing (0.1-100 pm)... 

Zeta potential determinations were made by the streaming potential method, with the apparatus described by Fuerstenau. Platinum electrodes were employed. The potential difference was measured with a pH meter Elpo N-512 (input 10 jj) an,j the conductivity with an Elpo RLC-bridge U 915 B. The driving pressure was usually between 4-6 cm Hg. The linearity of streaming potential versus the pressure was established for the range measured. Zeta potential values were calculated from the Smoluchowski equation. 

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