Dlvo Theory
Mostrando 1-12 de 12 artigos, teses e dissertações.
-
1. Recent Developments on the Elucidation of Colloidal Aspects of Asphaltenes and Their Relevance to Oilfield Problems
Asphaltenes constitute the heavy petroleum fraction responsible for deposition events that may lead to reduced oil production, therefore of great interest for flow assurance. These molecules self-assemble in solutions leading to formation of aggregates that eventually grow towards precipitation and blockages in reservoirs and pipelines. Based on the Yen-Mull
J. Braz. Chem. Soc.. Publicado em: 2020-02
-
2. Simulation of dense colloids
We present in this proceeding recent large scale simulations of dense colloids. On one hand we simulate model clay consisting of nanometric aluminum oxyde spheres in water using realistic effective electrostatic interactions and Van der Waals attractions, known as DLVO potentials and a combination of molecular dynamics (MD) and stochastic rotation dynamics (
Brazilian Journal of Physics. Publicado em: 2008-03
-
3. Modelagem da adesão de Bacillus cereus ao aço inoxidável em função do tempo e da temperatura e influência da rugosidade e da hidrofobicidade sobre a adesão / Modeling of adhesion of Bacillus cereus to stainless steel as function of time and temperature and influence of roughness and hydrophobicity in the adhesion
Adhesion of Bacillus cereus to stainless steel 304 #4 was evaluated after different times and temperatures of contact. Mathematical models were obtained capable of predicting the adhesion of B. cereus in stainless steel, as a function of temperature (4 oC 35 oC) and time (1d - 10 d). The interaction between the surface of stainless steel and B. cereus was st
Publicado em: 2008
-
4. Heterocoagulation of chrysotile with polytyrene latex / Heterocoagulação entre crisotila e latex de poliestireno
Chrysotile is a magnesium silicate with fibrous habit and ideal formula Mg6Si4O10(OH)8, having 1:1 layered structure of tetrahedral tridimite (silicate) with octahedral brucite (magnesium hydroxide). The layers are curved and rolled, resulting in cylindrical fibrils with brucite in the external surface and tridimite in the hollow internal surface. The fibril
Publicado em: 2007
-
5. Medidas do perfil da permissividade eletrica em interfaces solido-liquido, usando microscopia de força atomica
When immersed in water, several surfaces are electrically charged. Therefore, repulsive and attractive forces between the tip and the sample are detected during image generation by atomic force microscopy in aqueous medium. In the last decades repulsive forces have been attributed to electrostatic interactions, while attractive forces have been ascribed to v
Publicado em: 2001
-
6. Reversible and Irreversible Adhesion of Motile Escherichia coli Cells Analyzed by Total Internal Reflection Aqueous Fluorescence Microscopy
The initial events in bacterial adhesion are often explained as resulting from electrostatic and van der Waals forces between the cell and the surface, as described by DLVO theory (developed by Derjaguin, Landau, Verwey, and Overbeek). Such a theory predicts that negatively charged bacteria will experience greater attraction toward a negatively charged surfa
American Society for Microbiology.
-
7. Effects of Ionic Strength on Bacterial Adhesion and Stability of Flocs in a Wastewater Activated Sludge System
The success of biological wastewater treatment is to a large extent governed by the ability of bacteria to induce floc formation, thereby facilitating the separation of particles from the treated water. We performed studies on the dynamics of floc stability, the desorption of cells from the flocs, and the reflocculation of detached material. The floc stabili
-
8. Interactions between motile Escherichia coli and glass in media with various ionic strengths, as observed with a three-dimensional-tracking microscope.
Escherichia coli bacteria have been observed to swim along a glass surface for several minutes at a time. Settling velocities of nonmotile cells and a computer simulation of motile cells confirmed that an attractive force kept the bacteria near the surface. The goal of this study was to evaluate whether this attractive force could be explained by reversible
-
9. Electrolyte Effects on Attachment of an Estuarine Bacterium
The effect of electrolyte concentration on attachment of Vibrio alginolyticus to hydroxyapatite was determined. Bacterial affinity for attachment to the surface and surface capacity were derived from linearization of bacterial adsorption isotherms. At low concentrations (<0.1 M) the affinity of the bacteria for the surface increased with increasing ionic str
-
10. The height of biomolecules measured with the atomic force microscope depends on electrostatic interactions.
In biological applications of atomic force microscopy, the different surface properties of the biological sample and its support become apparent. Observed height differences between the biomolecule and its supporting surface are thus not only of structural origin, but also depend on the different sample-tip and support-tip interactions. This can result in ne
-
11. Reversal of Flagellar Rotation Is Important in Initial Attachment of Escherichia coli to Glass in a Dynamic System with High- and Low-Ionic-Strength Buffers
The attachment rates of wild-type, smooth-swimming, tumbly, and paralyzed Escherichia coli to glass was measured at fluid velocities of 0.0044 and 0.044 cms−1 (corresponding to shear rates of 0.34 and 3.4 s−1, respectively), in 0.02 and 0.2 M buffer solutions. At the highest ionic strength, we did not observe a significant difference in the attachment ra
American Society for Microbiology.
-
12. Species-specific long range interactions between receptor/ligand pairs.
Total internal reflection microscopy (TIRM) monitors Brownian fluctuations in elevation as small as 1 nm by measuring the scattering of a single sphere illuminated by an evanescent wave when the sphere is levitated by colloidal forces such as electrostatic double-layer repulsion. From the Boltzmann distribution of elevations sampled by the sphere over time,