Related Experiment Video
Updated: Jun 26, 2026
10:11
Temperature-Controlled Assembly and Characterization of a Droplet Interface Bilayer
Published on: April 19, 2021
Interfacial instability in bilayer films due to solvent evaporation
1Department of Chemistry, University of Durham, Durham DH1 3LE, UK. mireille.souche@durham.ac.uk
The European Physical Journal. E, Soft Matter
|January 14, 2009
Summary
This study analyzes Marangoni instability in thin fluid layers, crucial for understanding spin-coating. Results show evaporation and fluid properties significantly impact instability onset, aligning with experimental polymer solution observations.
Area of Science:
- Fluid dynamics
- Interface phenomena
- Chemical engineering
Background:
- Marangoni instability is critical in thin-film processes like spin-coating.
- Solvent evaporation drives concentration gradients, influencing fluid behavior.
- Understanding interfacial dynamics is key for process optimization.
Purpose of the Study:
- To conduct a linear analysis of Marangoni instability in a two-layer fluid system with evaporation.
- To investigate the impact of various parameters on instability onset.
- To compare theoretical findings with experimental observations of polymer solutions.
Main Methods:
- Linear stability analysis of a deformable interface.
- Modeling of convective and diffusive solvent transport.
- Parametric study including evaporation rate, viscosity, diffusivity, convection, and layer depths.
Main Results:
- The solvent evaporation rate significantly influences the onset of Marangoni instability.
- Ratios of viscosity, diffusivity, convection rate, and layer depths are critical factors.
- Theoretical predictions show satisfactory agreement with experimental spin-coating data.
Conclusions:
- The study provides a theoretical framework for Marangoni instability under realistic conditions.
- Findings offer insights into controlling thin-film instabilities in coating processes.
- The model's agreement with experiments validates its applicability to polymer solution spin-coating.
Related Concept Videos
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the concentration...
01:35Asymmetric Lipid Bilayer
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
01:26Membrane Fluidity
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
01:23Membrane Fluidity
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...
02:28Intermolecular Forces in Solutions
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,...
01:15Theories of Dissolution: Diffusion Layer Model
Dissolution, the process by which drug particles dissolve in a solvent, is explained by the diffusion layer model, a theoretical framework that simulates the absorption of oral drugs and allows us to analyze experimental data.
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...