Related Experiment Video
Updated: Oct 20, 2025
06:49
In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation
Published on: March 2, 2021
6.4K
Critical Solutal Marangoni Number Correlation for Short-Scale Convective Instabilities in Drying Poly(vinyl
Max Tönsmann1, Philip Scharfer1, Wilhelm Schabel1
1Karlsruhe Institute of Technology (KIT), Thin Film Technology (TFT), Kaiserstraße 12, 76131 Karlsruhe, Germany.
Polymers
|September 10, 2021
Summary
A new correlation predicts critical solutal Marangoni number in drying polymer films, aiding process design for uniform or self-assembled thin films.
Area of Science:
- Materials Science
- Chemical Engineering
- Fluid Dynamics
Background:
- Drying polymer films can exhibit surface instabilities driven by solutal gradients.
- Understanding these Marangoni instabilities is crucial for controlling film morphology.
Purpose of the Study:
- To develop an empirical correlation for the critical solutal Marangoni number.
- To relate this critical number to Péclet and Schmidt numbers for drying poly(vinyl acetate)-methanol films.
Main Methods:
- Utilized experimental flow field data and concentration profiles.
- Incorporated newly derived measurements and 1D drying simulations.
- Accounted for transient material properties during the drying process.
Main Results:
- Proposed a new empirical correlation for the critical solutal Marangoni number.
- The correlation accurately describes short-scale convective Marangoni instabilities with 9% accuracy.
- The correlation qualitatively aligns with theoretical predictions.
Conclusions:
- The developed correlation provides a tool for predicting Marangoni instabilities in drying polymer films.
- This facilitates process design for achieving desired thin film structures.
- Potential applications include producing uniform films or enabling deliberate self-assembly.
Related Concept Videos
01:28Vapor Pressure of Fluid
1.5K
The vapor pressure of a fluid is a crucial concept in fluid mechanics, influencing phenomena such as boiling and cavitation. Vapor pressure refers to the pressure exerted by a vapor at a state of thermodynamic equilibrium with its corresponding liquid phase at a specific temperature. It represents the tendency of molecules to escape from the fluid surface into the vapor phase.
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
1.5K
02:28Intermolecular Forces in Solutions
35.8K
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
35.8K
01:19Capillarity in Fluid
472
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...
472
01:01Distillation: Vapor–Liquid Equilibria
3.3K
Distillation is a separation technique that takes advantage of the boiling point properties of disparate elements in a mixture. To perform distillation, we begin by heating a miscible mixture of two liquids with a significant difference in boiling points (at least 20°C). As the solution heats up and reaches the bubble point of the more volatile component, some molecules of the more volatile component transition into the gas phase and travel upward into the condenser, which is a glass tube...
3.3K
01:16Titration in Nonaqueous Solvents
1.1K
Most acid-base titrations are performed in an aqueous medium. In aqueous titrations, water competes with weaker acids or bases for proton donation or acceptance, leading to ambiguous endpoints in the titration curve. Water also affects the partial ionization of weak acids or bases. For example, water accepts a proton from acetic acid to form hydronium and acetate ions. The hydronium ion formed is a stronger acid than acetic acid, and the acetate ion is a stronger base than water. As a result,...
1.1K
02:24Ideal Solutions
21.1K
According to Raoult’s law, the partial vapor pressure of a solvent in a solution is equal or identical to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution. However, Raoult's Law is only valid for ideal solutions. For a solution to be ideal, the solvent-solute interaction must be just as strong as a solvent-solvent or solute-solute interaction. This suggests that both the solute and the solvent would use the same amount of energy to escape to the...
21.1K