Related Experiment Video
Updated: Oct 18, 2025
05:58
Deposition of Porous Sorbents on Fabric Supports
Published on: June 12, 2018
6.7K
Particle Deposition in Drying Porous Media
1Navier Laboratory, University Gustave Eiffel, ENPC, CNRS, 77420 Champs-sur-Marne, France.
Materials (Basel, Switzerland)
|September 28, 2021
Summary
Drying porous media with suspended nanoparticles leads to non-uniform particle deposits. Nanoparticle deposition significantly reduces porosity, especially near the drying surface, impacting material properties.
Area of Science:
- Materials Science
- Fluid Dynamics
- Geophysics
Background:
- Drying of porous media is common in soils and building materials.
- Suspended particles in fluids can alter material properties through deposition.
- Particle deposition and drying kinetics are coupled phenomena, affecting porosity.
Purpose of the Study:
- Investigate the impact of nanoparticle deposition on porous media during drying.
- Characterize the depth-dependent distribution of nanoparticle deposits.
- Understand the relationship between initial particle concentration and deposit characteristics.
Main Methods:
- Scanning Electron Microscopy (SEM) for high-resolution imaging.
- X-ray microtomography for 3D structural analysis.
- Experimental drying of nanoparticle suspensions in porous media.
Main Results:
- Nanoparticle deposition reduced overall porosity.
- Deposit distribution was non-uniform with depth due to advection towards the drying surface.
- Pore size reduction was significant over a narrow length scale.
Conclusions:
- Particle advection during drying creates heterogeneous deposits in porous media.
- Initial volume fraction influences deposit depth and porosity reduction.
- Findings aid in designing porous materials and modeling drying processes with particle effects.
Related Concept Videos
00:52Washing, Drying, and Ignition of Precipitates
1.4K
After filtration, the precipitate is washed to remove coprecipitated impurities and any remaining mother liquor. Colloidal precipitates, such as silver chloride, are washed with an electrolyte (such as dilute nitric acid) to prevent the peptization of the precipitate. In the case of slightly soluble precipitates, the wash solution contains a common ion to reduce solubility. Lead sulfate, which is slightly soluble in water, is washed with dilute sulfuric acid. Similarly, wash solutions may be...
1.4K
01:20Porosity and Absorption of Aggregate
454
Aggregates contain pores of varying sizes; while some are completely enclosed within the particles, others open onto the surface, allowing water to penetrate. The porosity of aggregates is a major factor contributing to the overall porosity of concrete, given that aggregates constitute about three-quarters of concrete's volume.
When all pores in an aggregate are filled with water, the aggregate is considered saturated and surface-dry. If left in dry air, water will evaporate until the...
When all pores in an aggregate are filled with water, the aggregate is considered saturated and surface-dry. If left in dry air, water will evaporate until the...
454
01:16Precipitate Formation and Particle Size Control
1.3K
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...
1.3K
01:09Colloidal precipitates
1.1K
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...
1.1K
01:18Porosity in Cement Paste
263
The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
The balance of water to cement in the mix is...
The balance of water to cement in the mix is...
263
01:12Precipitation Processes
825
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
825