Related Experiment Video
Updated: Jun 16, 2025
08:02
Fabricating High-viscosity Droplets using Microfluidic Capillary Device with Phase-inversion Co-flow Structure
Published on: April 17, 2018
10.3K
Intricate Evaporation Dynamics in Different Multidroplet Configurations
Hari Govindha A1, Saravanan Balusamy1, Sayak Banerjee1
1Department of Mechanical and Aerospace Engineering, Indian Institute of Technology Hyderabad, Kandi 502284, Telangana, India.
Langmuir : the ACS Journal of Surfaces and Colloids
|August 19, 2024
Summary
Droplet arrays evaporate slower than single droplets due to a shielding effect that increases local vapor concentration. Lifetime increases with more droplets and closer spacing, but decreases with higher temperatures.
Area of Science:
- Fluid dynamics
- Heat and mass transfer
- Surface science
Background:
- Evaporation of sessile droplets is crucial in various industrial and natural processes.
- Understanding droplet array evaporation is key to optimizing applications like inkjet printing and cooling systems.
Purpose of the Study:
- To experimentally investigate the evaporation dynamics of sessile droplet arrays.
- To quantify the influence of droplet configuration, spacing, and temperature on evaporation lifetime.
- To compare experimental findings with a theoretical diffusion-based model.
Main Methods:
- Utilized a customized goniometer for side and top-view imaging.
- Monitored droplet height, spread, contact angle, and volume evolution.
- Varied droplet array configurations, separation distances, and substrate temperatures.
Main Results:
- Droplet array lifetime exceeds that of isolated droplets due to mutual shielding.
- Evaporation lifetime increases with droplet number and decreases with separation distance.
- Lifetime decreases with increasing substrate temperature following a power law, with diminished shielding at higher temperatures.
Conclusions:
- The shielding effect significantly influences droplet array evaporation dynamics.
- A diffusion-based model accurately predicts central droplet lifetime at room temperature but overpredicts at higher temperatures.
- Substrate temperature and droplet configuration impact local vapor concentration, affecting evaporation rates.
Related Concept Videos
02:39Phase Transitions: Vaporization and Condensation
17.5K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase...
17.5K
01:01Distillation: Vapor–Liquid Equilibria
2.7K
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...
2.7K
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
278
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...
278
01:15Theories of Dissolution: Diffusion Layer Model
720
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...
720
01:16Precipitate Formation and Particle Size Control
759
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...
759
02:34Vapor Pressure
34.7K
When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally collide with the surface of the condensed phase, and in some cases, these collisions will result in the molecules re-entering the condensed phase. The change from the gas phase to the liquid is called condensation. When the rate of condensation becomes equal to the rate of vaporization, neither the amount of the liquid nor the amount of the vapor...
34.7K