Related Experiment Video
Updated: Aug 25, 2025
06:24
Preparation of Nanoparticles for ToF-SIMS and XPS Analysis
Published on: September 13, 2020
8.1K
Particulate suspension coating of capillary tubes
D-H Jeong1, L Xing1, J-B Boutin1
1Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA. asauret@ucsb.edu.
Soft Matter
|October 14, 2022
Summary
This study investigates particle suspension displacement in capillary tubes, revealing three distinct coating regimes (liquid-only, heterogeneous, thick films) based on speed and particle properties. Effective viscosity predicts film thickness, but particle migration alters results in concentrated suspensions.
Area of Science:
- Fluid dynamics
- Colloid and surface science
- Materials science
Background:
- Particle suspension displacement in capillaries is crucial for applications like water purification and microplastic dispersion.
- The impact of dispersed particles on interfacial dynamics and residual liquid film properties is not well understood.
Purpose of the Study:
- To investigate the deposition of coating films on capillary tube walls during suspension plug translation.
- To identify deposition regimes and characterize coating film thickness as a function of key parameters.
Main Methods:
- Experimental study of suspension plug translation in a capillary tube driven by air.
- Characterization of coating film thickness and composition.
- Analysis of particle size, volume fraction, and translation speed effects.
Main Results:
- Three distinct coating regimes were identified: liquid-only, heterogeneous, and thick films.
- Film thickness, for films thicker than particle diameter, can be predicted by the suspension's effective viscosity.
- Shear-induced migration in concentrated suspensions leads to variations in volume fraction, affecting film thickness and composition.
Conclusions:
- Particle presence significantly influences capillary coating dynamics and film properties.
- Effective viscosity is a useful predictor for film thickness, but particle migration effects must be considered for concentrated systems.
- Understanding these mechanisms is vital for optimizing industrial processes involving particle suspensions.
Related Concept Videos
01:09Colloidal precipitates
724
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...
724
01:17Colloids and Suspensions
2.0K
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...
2.0K
01:18Rise of Liquid in a Capillary Tube
2.2K
When very thin cylindrical tubes, called capillaries, are dipped in a liquid, the liquid rises or falls in the tube compared to the surrounding liquid. This phenomenon is called capillary action. Capillary action occurs due to the combination of two opposing forces: the cohesive forces of the liquid, which cause it to stick to itself and form a rounded shape, and the adhesive forces between the liquid and the walls of the container, which cause the liquid to be attracted to the container walls.
2.2K
03:22Colloids
17.8K
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...
17.8K
01:19Capillarity in Fluid
326
Capillarity describes the movement of liquid in small spaces without external forces acting on it. The capillarity is driven by surface tension and adhesive interactions between the liquid and surrounding solid surfaces. This effect is often seen in narrow tubes, porous materials, and fine particles.
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
326