Related Experiment Video
Updated: May 22, 2026
06:26
Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source
Published on: August 17, 2018
Colloidal interactions in liquid CO2--a dry-cleaning perspective.
Soumi Banerjee1, Stevia Sutanto, J Mieke Kleijn
1Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, Wageningen University, Wageningen, The Netherlands. Soumi.Banerjee@wur.nl
Advances in Colloid and Interface Science
|April 28, 2012
Summary
Liquid carbon dioxide (CO2) offers an eco-friendly dry-cleaning alternative, but stronger soil adhesion due to van der Waals forces presents challenges. Optimizing additives and fluid dynamics is key to improving CO2 dry-cleaning performance.
Area of Science:
- Colloid and Interface Science
- Green Chemistry
- Textile Science
Background:
- Traditional dry-cleaning solvents like perchloroethylene (PERC) pose environmental and health risks.
- Liquid carbon dioxide (CO2) is a promising, non-toxic, and sustainable alternative for industrial dry-cleaning.
- Commercial application of CO2 dry-cleaning is nascent, facing significant technical hurdles.
Purpose of the Study:
- To review the current state of liquid CO2 dry-cleaning technology.
- To analyze the fundamental detergency challenges in CO2-based systems.
- To explore theoretical solutions for improving the efficacy of CO2 dry-cleaning.
Main Methods:
- Analysis of liquid CO2 properties (dielectric constant, density, viscosity, surface tension, etc.).
- Theoretical modeling of interparticle forces (van der Waals) between soil and fabric in CO2.
- Application of the Washburn-Lucas equation to predict wetting phenomena in CO2 systems.
- Theoretical examination of mechanical action and fluid dynamics (Reynolds number) in CO2 dry-cleaning.
Main Results:
- Van der Waals forces between model soil (silica) and fabric (cellulose) are significantly stronger in liquid CO2 than in water or PERC.
- Electrostatic stabilization for preventing soil redeposition is challenging in liquid CO2; use of large-anion electrolytes is discussed.
- Additives like water, alcohol, and surfactants play complex roles; water can enhance soil adhesion via capillary bridges.
- Near-complete wetting is essential for effective detergency, as predicted by the Washburn-Lucas equation.
- Higher Reynolds numbers are required in CO2 dry-cleaning to overcome soil-fabric binding forces compared to PERC or water.
Conclusions:
- The strong van der Waals forces and low viscosity of liquid CO2 necessitate higher mechanical energy input for effective soil removal.
- Understanding and manipulating interfacial phenomena, including wetting and additive interactions, are crucial for optimizing CO2 dry-cleaning.
- Further research into electrostatic stabilization and fluid dynamics is needed to overcome the inherent challenges of liquid CO2 detergency.
Related Concept Videos
01:09Colloidal precipitates
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...
01:29The Colloidal State
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 the...
01:06Coagulation
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...
03:22Colloids
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...
01:17Colloids and Suspensions
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...
03:00Solubility
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...