Related Experiment Video
Updated: Apr 30, 2026
08:38
Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions
Published on: February 15, 2019
16.4K
Particle segregation in a sedimenting bidisperse soft sphere system
Matthias Kohl1, Michael Schmiedeberg
1Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany. mkohl@thphy.uni-duesseldorf.de.
Soft Matter
|May 7, 2014
Summary
This study explores binary colloidal soft sphere sedimentation. Complex multi-step segregation occurs, forming clusters and unique phases, not just simple particle movement.
Area of Science:
- Soft Matter Physics
- Colloidal Science
- Statistical Mechanics
Background:
- Sedimentation is a fundamental process in colloidal systems.
- Understanding particle interactions and phase behavior is crucial for predicting system evolution.
Purpose of the Study:
- To investigate the sedimentation dynamics of a binary colloidal soft sphere system.
- To predict and confirm the final states and complex phase behaviors during sedimentation.
Main Methods:
- Theoretical prediction using equations of state in small and large pressure limits.
- Validation through Brownian dynamics simulations.
Main Results:
- Observed multi-step segregation processes, not single particle movements.
- Formation of species-specific clusters and complex final phases.
- Identification of metastable network-like structures.
Conclusions:
- Gravity-driven segregation in binary soft sphere systems is a complex, multi-stage process.
- Predictive models combined with simulations accurately capture emergent complex phases and structures.
Related Concept Videos
01:29The Colloidal State
184
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called...
184
01:05Centrifugation
6.9K
Centrifugation is a separation technique based on differences in density or size. It is commonly used to separate solids from aqueous interferents. During centrifugation, the sample is placed in centrifugation tubes and spun at high angular velocity, which allows centrifugal force to act differentially on the different densities or masses of the components. After spinning, the supernatant liquid is decanted. Depending on the specific application, either the pellet or the supernatant is retained...
6.9K
01:17Colloids and Suspensions
3.4K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is...
3.4K
01:09Colloidal precipitates
5.7K
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
5.7K
03:22Colloids
17.2K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
17.2K
01:16Precipitate Formation and Particle Size Control
5.8K
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
5.8K