scholarly journals A Simple Method to Determine Critical Coagulation Concentration from Electrophoretic Mobility

2020 ◽  
Vol 4 (2) ◽  
pp. 20 ◽  
Author(s):  
Marco Galli ◽  
Szilárd Sáringer ◽  
István Szilágyi ◽  
Gregor Trefalt
Keyword(s):  
Electrophoretic Mobility ◽  
Dlvo Theory ◽  
Computational Method ◽  
Particle Aggregation ◽  
Critical Coagulation Concentration ◽  
Simple Method ◽  
Interparticle Forces ◽  
Mobility Data ◽  
Key Parameter ◽  
Multivalent Electrolytes

Critical coagulation concentration (CCC) is a key parameter of particle dispersions, since it provides the threshold limit of electrolyte concentrations, above which the dispersions are destabilized due to rapid particle aggregation. A computational method is proposed to predict CCC values using solely electrophoretic mobility data without the need to measure aggregation rates of the particles. The model relies on the DLVO theory; contributions from repulsive double-layer forces and attractive van der Waals forces are included. Comparison between the calculated and previously reported experimental CCC data for the same particles shows that the method performs well in the presence of mono and multivalent electrolytes provided DLVO interparticle forces are dominant. The method is validated for particles of various compositions, shapes, and sizes.

Flocculation of Waste Waters from Petroleum Refineries

1974 ◽  
Vol 9 (1) ◽  
pp. 302-314
Author(s):  
André Hade ◽  
Acher Elcabetz
Keyword(s):  
Electrophoretic Mobility ◽  
Light Transmittance ◽  
Waste Waters ◽  
Critical Coagulation Concentration ◽  
Mobility Rate ◽  
Anionic Polymers ◽  
Petroleum Refineries ◽  
Binary Suspension

Abstract Waste waters from petroleum refineries can be considered as a ternary-like system, the components of which have been characterized. They are: the alkaline liquor, the hydrocarbon rich oil in suspension and the silica rich solid also in suspension. The parameters controlling the destabilization and the flocculation of these suspensions have been studied by light transmittance and electrophoretic mobility. Rate of flocculation, critical coagulation concentration (CCC) , critical restabilization concentration and optimum flocculation conditions have been determined for different combinations of added polyelectrolytes and/or simple electrolytes. Among eleven different polyelectrolytes, four of the cationic type were selected for their property to flocculate the suspension. It has been shown that an excess of polyelectrolyte brings about the restabilization of the particules. No flocculation has been observed for any of the anionic polymers tested. Simple electrolytes are found to obey the Schulze-Hardy rule in their flocculation capacity. Various combinations of a polyelectrolyte with a simple salt lead to a lower CCC together with a broader concentration range between destabilization and restabilization. It is concluded that this binary suspension behaved essentially like a classical lyophobic sol.

scholarly journals Communication: On the Stability and Necessary Electrophoretic Mobility of Bare Oil Nanodroplets in Water

2020 ◽  
Author(s):  
Saranya Pullanchery ◽  
Sergey Kulik ◽  
halil okur ◽  
Hilton. B. de Aguiar ◽  
Sylvie Roke
Keyword(s):  
Electrophoretic Mobility ◽  
Dlvo Theory ◽  
Air Bubbles ◽  
Oil Droplets ◽  
Cleaning Procedure ◽  
Charged Droplets ◽  
Oil In Water ◽  
The Creation ◽  
The Stability ◽  
The 19Th Century

Hydrophobic oil droplets, particles and air bubbles can be dispersed in water as kinetically stabilized dispersions. It has been established since the 19th century that such objects harbor a negative electrostatic potential roughly twice larger than the thermal energy. The source of this charge continues to be one of the core observations in relation to hydrophobicity and its molecular explanation is still debated. What is clear though, is that the stabilizing interaction in these systems is understood in terms of electrostatic repulsion via DLVO theory. Recent work [Carpenter et al., PNAS 116 (2019) 9214] has added another element into the discussion, reporting the creation of bare near-zero charged droplets of oil in water that are stable for several days. Key to the creation of the droplets is a rigorous glassware cleaning procedure. Here, we investigate these conclusions and show that the cleaning procedure of glassware has no influence on the electrophoretic mobility of the droplets, that oil droplets with near-zero charge are unstable, and provide an alternative possible explanation for the observations involving glass surface chemistry.

scholarly journals Homogenization of the 1D Peri-static/dynamic Bar with Triangular Micromodulus

2020 ◽  
Author(s):  
Kjell Eriksson ◽  
Christer Stenström
Keyword(s):  
Boundary Effects ◽  
Elastic Behavior ◽  
Nonlocal Model ◽  
End Effects ◽  
Simple Method ◽  
Interparticle Forces ◽  
Linear Elastic ◽  
Interparticle Force ◽  
Material Points ◽  
Force Range

Abstract In peridynamics, boundary effects generally appear due to nonlocality of interparticle forces; in particular, end effects are found in 1D bars. In a previous work by Eriksson and Stenström (J Peridyn Nonlocal Model 2(2):205–228, 2020), a simple method to remove end effects in certain types of 1D bars, or to homogenize such bars, was presented for bars with constant micromodulus. In this work, which is a continuation of Eriksson and Stenström (J Peridyn Nonlocal Model 2(2):205–228, 2020), the homogenizing procedure is applied to bars with a linear, or “triangular,” micromodulus. For the examples studied, common in practice, the linear elastic behavior of a homogenized bar, is identical to that of a corresponding classical continuum mechanics bar, independently of the interparticle force range and total number of material points of the bar.

scholarly journals High-concentration zeta potential measurements using light-scattering techniques

2010 ◽  
Vol 368 (1927) ◽  
pp. 4439-4451 ◽  
Author(s):  
Michael Kaszuba ◽  
Jason Corbett ◽  
Fraser Mcneil Watson ◽  
Andrew Jones
Keyword(s):  
Light Scattering ◽  
Zeta Potential ◽  
Electrophoretic Mobility ◽  
Electrostatic Interactions ◽  
Theoretical Models ◽  
High Concentration ◽  
Sample Concentration ◽  
High Concentrations ◽  
Laser Doppler Electrophoresis ◽  
Key Parameter

Zeta potential is the key parameter that controls electrostatic interactions in particle dispersions. Laser Doppler electrophoresis is an accepted method for the measurement of particle electrophoretic mobility and hence zeta potential of dispersions of colloidal size materials. Traditionally, samples measured by this technique have to be optically transparent. Therefore, depending upon the size and optical properties of the particles, many samples will be too concentrated and will require dilution. The ability to measure samples at or close to their neat concentration would be desirable as it would minimize any changes in the zeta potential of the sample owing to dilution. However, the ability to measure turbid samples using light-scattering techniques presents a number of challenges. This paper discusses electrophoretic mobility measurements made on turbid samples at high concentration using a novel cell with reduced path length. Results are presented on two different sample types, titanium dioxide and a polyurethane dispersion, as a function of sample concentration. For both of the sample types studied, the electrophoretic mobility results show a gradual decrease as the sample concentration increases and the possible reasons for these observations are discussed. Further, a comparison of the data against theoretical models is presented and discussed. Conclusions and recommendations are made from the zeta potential values obtained at high concentrations.

Description of colloidal particles aggregation in the presence of Hofmeister effects: on the relationship between ion adsorption energy and particle aggregation activation energy

2018 ◽  
Vol 20 (35) ◽  
pp. 22831-22840 ◽  
Author(s):  
Yaxue Luo ◽  
Hang Li ◽  
Xiaodan Gao ◽  
Rui Tian
Keyword(s):  
Activation Energy ◽  
Adsorption Energy ◽  
Colloidal Particles ◽  
Dlvo Theory ◽  
Particle Aggregation ◽  
Ion Adsorption ◽  
The Relationship

Upon extending the DLVO theory by taking into account the Hofmeister effects, the predicted CCC values match well with experimental CCCs.

scholarly journals Studies on metatherian sex chromosomes. XII. Sex-linked inheritance and probable paternal X-inactivation of a-galactosidase A in Australian marsupials.

1983 ◽  
Vol 36 (6) ◽  
pp. 511 ◽  
Author(s):  
DW Cooper ◽  
PA Woolley ◽  
GM Maynes ◽  
FS Sherman ◽  
WE Poole
Keyword(s):  
Genetic Variation ◽  
Electrophoretic Mobility ◽  
Dosage Compensation ◽  
Sex Chromosomes ◽  
Phylogenetic Relationships ◽  
X Inactivation ◽  
Mobility Data

An investigation of genetic variation in the electrophoretic mobility of the enzyme a-galactosidase A (EC 3.2.1.22) has been carried out for 33 species of Australian metatherian (marsupial) mammals. The results are compatible with the enzyme being sex-linked in macropodids (kangaroos and wallabies) and probably in dasyurids (marsupial 'mice', etc.), as it is in eutherian (placental) mammals. The results also suggest that the mode of dosage compensation for this locus is the same as for other sexlinked loci in kangaroos, i.e. paternal X inactivation, rather than the random X inactivation system of eutherian mammals. The bearing of the enzyme mobility data on phylogenetic relationships among macropodid species is discussed.

Cellular electrophoretic mobility data: A first approach to a database

1997 ◽  
Vol 18 (7) ◽  
pp. 1109-1119 ◽  
Author(s):  
George G. Slivinsky ◽  
Wesley C. Hymer ◽  
Johann Bauer ◽  
Dennis R. Morrison
Keyword(s):  
Electrophoretic Mobility ◽  
Mobility Data

scholarly journals The role of vascular complexity on optimal junction exponents

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Keelan ◽  
James P. Hague
Keyword(s):  
Physiological Parameters ◽  
Computational Method ◽  
Vascular Networks ◽  
Arterial Tree ◽  
Tree Structures ◽  
Fundamental Properties ◽  
Metabolic Costs ◽  
The Stability ◽  
Key Parameter

AbstractWe examine the role of complexity on arterial tree structures, determining globally optimal vessel arrangements using the Simulated AnneaLing Vascular Optimization algorithm, a computational method which we have previously used to reproduce features of cardiac and cerebral vasculatures. In order to progress computational methods for growing arterial networks, deeper understanding of the stability of computational arterial growth algorithms to complexity, variations in physiological parameters (such as metabolic costs for maintaining and pumping blood), and underlying assumptions regarding the value of junction exponents is needed. We determine the globally optimal structure of two-dimensional arterial trees; analysing how physiological parameters affect tree morphology and optimal bifurcation exponent. We find that considering the full complexity of arterial trees is essential for determining the fundamental properties of vasculatures. We conclude that optimisation-based arterial growth algorithms are stable against uncertainties in physiological parameters, while optimal bifurcation exponents (a key parameter for many arterial growth algorithms) are affected by the complexity of vascular networks and the boundary conditions dictated by organs.

scholarly journals Center Impedance Method for Estimating Complex Modulus with Wide Frequency Range and Large Loss Factors

2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Ryuzo Horiguchi ◽  
Yoshiro Oda ◽  
Keito Sato ◽  
Hiroto Kozuka ◽  
Takao Yamaguchi
Keyword(s):  
Loss Factor ◽  
Wide Frequency Range ◽  
Frequency Function ◽  
Single Frequency ◽  
Impedance Method ◽  
Frequency Range ◽  
Simple Method ◽  
Large Loss ◽  
Mobility Data ◽  
Loss Factors

A simple method for determining viscoelasticity over a wide frequency range using the frequency response function (FRF) mobility obtained by the center impedance method is presented. As user data comprise the FRF between the velocity of the excitation rod and excitation force, it is challenging to separate the signal and noise. Our proposed method is based on the FRF obtained from the analytical solution of the equation of motion of the viscoelastic beam and relationship between the complex wavenumber (real wavenumber and attenuation constant) of flexural wave and viscoelasticity. Furthermore, a large loss factor can be handled over a wide frequency range without using the half-power bandwidth. In this study, actual FRF mobility data containing noise were processed using preprocessing, inverse calculation, and postprocessing. Preprocessing removed low-coherence data, compensates for the effects of instrument gain, and transformed the FRF into its dimensionless equivalent. Then, inverse calculations were used to solve the mobility equation and determine the complex wavenumber. In postprocessing, the complex wavenumber obtained by the inverse calculation was curve fitted using functions with mechanical significance. Consequently, the storage modulus based on the curve-fitted complex wavenumber was a monotonically increasing frequency function. The loss factor had a smooth frequency dependence such that it has the maximum value at a single frequency. The proposed method can be applied to composite materials, where the application of time-temperature superposition is challenging. We utilized the measured FRF mobility data obtained over a duration of several seconds, and this method can also be applied to materials with large loss factors of 1 or more.

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