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Critical Factors Affecting the Synthesis of Bionanomaterials and Biocomposites
Published in Naveen Dwivedi, Shubha Dwivedi, Bionanotechnology Towards Sustainable Management of Environmental Pollution, 2023
Rachita Sharma, Priya Singh, Ved Kumar Mishra, Naveen Dwivedi, Nikita Singhal
Zeta potential is a net potential developed at the surface of the particle when it is in contact with the liquid medium. It gives the information of stability of the colloids. Colloids with higher values of zeta potential (whether negative or positive) are considered more stable. When the charges between the particles and liquid medium are opposite, they will attract each other, while the same charge between particle and medium will cause repulsion. Lower value of zeta potential results in agglomeration. This zeta potential is also used to determine the stability of metal oxide nanoparticles for better shelf-life and more reliable physical properties. The zeta sizer is an instrument used to calculate the zeta potential. It also helps to study the surface charge on metal oxide nanoparticles in suspension to determine the influence of concentration on their properties (Wang et al., 2013).
Characterization Techniques for Bio-Nanocomposites
Published in Shrikaant Kulkarni, Neha Kanwar Rawat, A. K. Haghi, Green Chemistry and Green Engineering, 2020
The magnitude of the zeta potential measures the stability of the potential for given colloidal solution. If the particles in colloidal dispersion have a either too negative or positive zeta potential say + 30 mV, they have a tendency to repel one another, and don’t aggregate and settle. Such colloidal systems are considered as stable. Moreover, the particles having low zeta potential values tend to agglomerate and flocculate. The key factor that influences zeta potential is pH. A zeta potential value without a mention of pH is meaningless. The pH value at which the zeta potential is zero is called the isoelectric point. It is the value at which the given colloidal solution has the lowest stability. One more influential factor affecting zetametry measurement is the ionic strength. The zeta potential depends upon the kind and strength of ions that interact with the particle surface in solution. Thus, it is of vital importance to conduct experiments using an electrolyte (say NaCl) at low concentration.
Colloidal Interactions of Magnetic Nanoparticles
Published in Jeffrey N. Anker, O. Thompson Mefford, Biomedical Applications of Magnetic Particles, 2020
O. Thompson Mefford, Steven L. Saville
where UE is the electrophoretic mobility, ε is the dielectric constant of the medium, Z is the zeta potential, η is the viscosity of the medium, and f (k) is defined as the Henry function. The Henry function is usually defined as either 1 or 1.5, depending on the type of system. For particle systems larger than 200 nm in moderately concentrated electrolyte solutions, the Henry function used is 1.5 and is commonly referred to as the Smoluchowski approximation. For small particles in low dielectric constant media or non-aqueous media, the Henry function used is 1, usually referred to the Huckel approximation. Zeta potential therefore is not typically directly measured, rather calculated by measuring the electrophoretic mobility.
Formulation of roselle extract water-in-oil nanoemulsion for controlled pulmonary delivery
Published in Journal of Dispersion Science and Technology, 2023
Adil Omer Baba Shekh, Roswanira Abdul Wahab, Nur Azzanizawaty Yahya
The zeta potential of a NE is a measurement of the system's long-term stability against flocculation. A zeta potential value of ± 25 mV or higher is considered stable w/o NE.[42] Since the zeta potential of the w/o roselle extract NE was −49.0 ± 0.8 mV, it implied a system dominated by electrostatic repulsion, ensuring the NE's stability. The large zeta potential of either positive or negative value, as seen here, suggests a high energy barrier or repulsion between droplets in the w/o roselle extract NE.[55] The negatively charged zeta potential (S3b) was due to the surfactants' polyoxyethylene chains in Tween 80,[56] pointing to adequate Van der Waals electrostatic repulsions to stabilize and disperse the w/o system for an extended duration.[57]
Chemotactic movement and zeta potential dominate Chlamydomonas microsphaera attachment and biocathode development
Published in Environmental Technology, 2023
Guowei Chen, Zhen Hu, Ali Ebrahimi, David R. Johnson, Fazhu Wu, Yifei Sun, Renhao Shen, Li Liu, Gang Wang
Zeta potential is the electrical potential at the boundary of the surrounding liquid layer attached to the moving particles in the medium. The high absolute value of zeta potential generates a repulsive electrostatic force between particles, thus a more stable suspension [23,58]. The stability of planktonic cells depends upon the absolute high value of zeta potential, where low absolute zeta potential values (<30 mV) of either positive or negative charge tend to promote aggregation or attachment [59]. Zeta potential is affected not only by the properties of particles, but also the nature of the solution, such as pH, ionic strength, and temperature. In this study, similar patterns of zeta potential changes were observed under various nitrate or phosphate concentrations. For example, the zeta potential of the C. microsphaera cells was found to gradually increase from about −20 to −15 mV when the initial nitrate or phosphate concentration was elevated from 0 to 25 mg/L, and then slowly dropped down to around −16 mV when the initial nitrate or phosphate was further increased to 250 mg/L (Figure 6). Noticeably, all absolute values of zeta potential at various nitrate or phosphate dilution rates were smaller than 30 mV, indicating the limiting effect on cell attachment.
Characterization and stabilization of iron ore suspension and influence of the mixture of natural additive Sapindus mukorossi and SDS on the slurryability
Published in Journal of Dispersion Science and Technology, 2023
Zeta or electrokinetic potential is the electrostatic attraction or repulsion of charged particles in an emulsion or slurry. The electrophoretic mobility of charged particles is the measure of zeta potential. The magnitude of zeta potential decides the optimum suspension and emulsion compositions in slurry.[70–71] It is also used for forecasting the optimum quantity of dispersed phase and dispersion medium in colloidal suspension. Zeta potential for slurry-additive mixture is obtained using a particle size analyzer (Litesizer 500 Anton Paar, Austria). Samples are prepared by mixing 1 g of iron ore sample in 100 mL of deionized water. The slurry solution is well mixed by a magnetic stirrer at room temperature for 15 min. The experiment is performed thrice with 1 mL of this mixed slurry sample and considers the average. The reproducibility of the zeta potential value is within experimental error (1 mV).