Zeta Potential
How to calculate the zeta potential of a solution? There are some things you need to know first. Read on to learn about Isoelectric point and Electrophoretic mobility. Also learn about Laser Doppler electrophoresis. This article contains useful information on zeta potential. It also covers other important topics related to electrophoresis. Let’s get started! So, what is zeta potential?
Calculation of zeta potential
Zeta potential is a measure of the electrical charge of a molecule. It begins inside the diffuse layer and ends in the general solution. The zeta potential is the electric charge of a molecule when it reaches equilibrium with itself and the surrounding electrolyte. In a model of an electrolyte, this potential is equal to the total charge of the particle. Calculating zeta potential requires a few steps, and the results are often close to the numerical solution given by O’Brien-White.
Electrophoretic light scattering (ELS) is another method used to calculate zeta potential of particles. Unlike streaming potential measurements, this method induces movement of particles. The particles migrate at different rates due to the electric field. Highly charged particles move faster than those that are less charged. This method is used to determine the zeta potential of mixtures. It is important to note that these methods are more sensitive than the simplest spectrometers.
In the first step of determining the zeta potential, velocity measurements of electroosmotic flow through a microchannel are performed. This data is used to develop a three-dimensional model and calculate the zeta potential. This method is accurate, allowing for accurate estimation of the zeta potential. Once the model is established, the results of the computation can be compared with those of previous experiments.
Another important step in the process is to choose the right electroacoustic equation. There are several theories for calculating the zeta potential of microfluidic substrates. Generally, the zeta potential of a microfluidic substrate depends on the concentration, valency, and temperature. Consequently, calculating the zeta potential of a microfluidic material requires a good understanding of electroacoustic theory and experimental procedures.
In a modern day lab, the zeta potential is measured by using the PTFE measuring beaker. A piston is placed inside the beaker and oscillates at a constant frequency. Particles become immobilised on the surface of the beaker, and the fluid stream around the piston creates an oscillating frequency. An electrode on either side of the beaker detects this potential, which is then used to calculate the zeta potential. Traditionally, this method has been problematic due to particle agglomeration and sedimentation.
Isoelectric point
The isoelectric point of a substance or solution is the lowest possible value of a material’s zeta potential. This property is often desirable, for example, in water reclamation. Specifically, it can be used to determine the concentration of a particulate at a certain pH. The zeta potential of a given particulate is a key factor in determining the quality of the finished product.
A particle in aqueous solution has an ionic double layer surrounding its surface, which moves as a single unit with the particle. This double layer also varies the particle’s hydrodynamic diameter. The edge of the double layer is the isoelectric point, where the relative potential is zero. The point is commonly defined as the isoelectric point and is determined by the pH range the particle is suspended in.
TeO2 exhibits a low zeta potential in aqueous solutions and a high IEP in acidic solutions. In addition, it strongly adsorbs multivalent inorganic cations such as Ba. In this way, it can be seen that the negative charge of TeO2 partially balances the positive charge of the adsorbed CTMA cations.
It is important to note that measurements of the isoelectric point are difficult and often require careful procedures. However, in certain circumstances, the isoelectric point of a material can be productive. In the case of iron oxide, for instance, it is a very useful property to have in an electrochemical device. And it is the same for aliphatic hydrocarbons. Therefore, these materials exhibit high isoelectric points.
This physical characteristic is useful for determining the zeta potential of a material. It requires careful consideration and research in order to provide accurate results. Particle Technology Labs has extensive experience finding appropriate test conditions for a variety of materials. For more information, contact us today. We are happy to answer any questions you may have about zeta testing. The lab is the only place to go when you’re in need of accurate results and quality service.
The zeta potential is important because it helps predict long-term stability. For example, a particle with a zeta potential greater than +60 mV will have good stability, while one with a zeta potential between -10 mV and +10 mV will be unstable. In addition, the zeta potential can be used to predict surface chemistry changes. For example, moving from a citrate-based surface to one containing PEG will reduce the zeta potential and change the sign.
Electrophoretic mobility
The electrophoretic mobility of colloidal particles has been numerically studied. The zeta potential has been applied to study electrophoretic mobility. Other approaches have been studied as well, such as the double layer thickness and the dynamic Stern layer model. These approaches account for various aspects of hydrodynamic interactions. Other approaches have been investigated and compared to experimental observations. Here we will describe one such approach. It is a numerical simulation approach that allows us to study electrical conductivity and electrophoretic mobility of colloidal particles.
The electrophoretic mobility of lysozyme crystals is studied at 283 K in 1.5% NaCl and various pH values. We found that the zeta potential increases as the pH falls, from +8 to +24 mV. This is because pH affects the free charge of the molecule. The charge on the crystal is caused by H+ adsorption.
The electrokinetic potential is defined as the electrostatic potential at an arbitrarily separated region of a liquid medium. Electrophoretic methods are often used to determine the z-potential of particles. This can be calculated from the mobility of particles. The streaming potential is a theoretically valid method for obtaining the zeta potential. It is used in electrophoresis and enables the estimation of z-potential from particle mobility.
For high-concentration samples, the zeta potential can be measured at a low concentration using a high-concentration zeta potential cell. The maximum concentration of the sample measurable is 0.4 and up, depending on the size of the particle, polydispersity of the sample, and optical properties of the particles. In some cases, the mobility is too low for the detection of a small concentration of the sample.
The zeta potential of water-based samples is more realistic, but still shows concentration dependence. In such a case, the sample may have viscosity issues, which make it non-Newtonian. In addition, at high concentrations, the average particle spacing becomes very small. The ionic strength of the dispersant determines the thickness of the electrical double layer. This information is vital in evaluating the quality of a colloidal sample.
Laser Doppler electrophoresis
The Doppler effect is a phenomenon in which the frequency of light scattered by a moving particle shifts when compared to reference light. The Doppler effect can be measured with the help of heterodyne optics. In this method, light scattered by a moving particle has a higher frequency than the light incident on a stationary particle. Therefore, the Doppler effect is also used to determine the size of the particle.
To achieve high concentration, a high-concentration zeta potential cell is used. The instrument is equipped with a high-concentration zeta potential cell, which enables measurements of electrophoretic mobility in samples with a high concentration. However, conversion from mobility values to zeta potential values is complicated. In this paper, we present a summary of the measurements made on various kinds of samples and discuss how concentration relates to zeta potential values. The measurements were performed at 25degC on a Zetasizer Nano ZS fitted with a highconcentration zeta potential cell (ZEN1010).
The SZ100 method of laser Doppler electrophoresis uses the Smulochowski model to calculate the zeta potential of the sample. The sample particles are suspended in a solvent, which is irradiated with laser light of wavelength l. The frequency shift between the sample particles and the laser light determines the velocity of the sample particle V. The mobility is then calculated using the Smulochowski model.
The zeta potential is a key indicator of colloidal stability. A laser Doppler electrophoresis instrument enables the measurement of zeta potential from particles ranging from 3.8 nm to 100 mm in diameter. To measure zeta potential, the litesizer(tm) 500 measures the electrophoretic mobility of samples in a wide range of sizes and concentrations.
