Related Experiment Video
Updated: Dec 20, 2025
07:18
Measuring the Interaction Force Between a Droplet and a Super-hydrophobic Substrate by the Optical Lever Method
Published on: June 14, 2019
7.0K
Nonlinear theory of wetting on deformable substrates.
Julien Dervaux1, Matthieu Roché1, Laurent Limat1
1Laboratoire Matière et Systèmes Complexes, CNRS UMR 7057, Université de Paris, Université Paris Diderot, 10 Rue A. Domon et L. Duquet, F-75013 Paris, France. julien.dervaux@univ-paris-diderot.fr.
Soft Matter
|May 28, 2020
Summary
Understanding liquid spreading on soft materials is crucial. This study introduces a theory explaining contact line motion, revealing opposing capillary and visco-elastic forces for better predictions.
Area of Science:
- Soft matter physics
- Fluid dynamics
- Surface science
Background:
- Liquid spreading on undeformable solids is understood, but mechanisms on soft, deformable materials remain unclear.
- No consensus exists on the physical principles governing liquid drop behavior on soft substrates.
- This gap hinders applications relying on liquid-solid interactions with deformable surfaces.
Purpose of the Study:
- To develop a theoretical framework for liquid spreading on soft deformable materials.
- To elucidate the physical mechanisms governing the triple line's behavior.
- To provide predictive models for dynamic contact angles and emergent phenomena.
Main Methods:
- Application of the nonlinear theory of discontinuities to model the triple line on soft materials.
- Derivation of an analytic formula relating dynamic contact angle to drop velocity for various rheologies.
- Specialization of the formula for elastomers exhibiting Chasset-Thirion (power-law) rheologies.
Main Results:
- Identified nonlinear localized capillary and visco-elastic forces opposing contact line motion.
- Developed an explicit analytic formula for dynamic contact angle as a function of velocity.
- Demonstrated excellent agreement between theoretical predictions and experimental data for elastomers without adjustable parameters.
- Showcased the framework's ability to reproduce classical wetting models.
- Predicted novel dynamic behaviors for viscous drops on visco-elastic materials, including apparent hysteresis.
Conclusions:
- The proposed theoretical framework accurately describes liquid spreading on soft materials.
- Nonlinear force balances are key to understanding dynamic wetting on deformable substrates.
- The model offers a powerful tool for predicting and understanding complex wetting phenomena in soft matter systems.
More Related Videos
Related Concept Videos
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
682
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...
682
02:57Surface Tension, Capillary Action, and Viscosity
32.2K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
32.2K
01:22Surface Tension of Fluid
1.1K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
1.1K
01:15Theories of Dissolution: Diffusion Layer Model
1.5K
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...
1.5K
01:04Hydrostatic Pressure Force on a Curved Surface
2.4K
Hydrostatic pressure on curved surfaces is a fundamental concept in fluid mechanics with broad applications in the civil engineering field. When fluid is in contact with a curved surface, as in a reservoir, dam, or storage tank, it exerts pressure that varies in magnitude and direction along the curved surface. To assess the total hydrostatic force exerted by the fluid on a curved structure, engineers typically isolate the fluid volume adjacent to the surface and analyze the forces acting on...
2.4K
01:19Capillarity in Fluid
707
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...
707