The influence of surface tension gradients on drop coalescence

John Bush
2009
Journal paper

Abstract

We present the results of a combined experimental and numerical investigation of the coalescence of a drop with a liquid reservoir of a miscible but distinct fluid. Particular attention is given to elucidating the influence on the coalescence process of a surface tension difference between drop and reservoir. Drops are gently deposited on the surface of the reservoir, and so coalesce with negligible initial vertical velocity. Depending on the drop size and reservoir composition, partial or total coalescence may occur. Three distinct regimes, depending on the reservoir to drop surface tension ratio, Rσ, are identified and delineated through both experiments and numerics. If Rσ

Official source

https://infoscience.epfl.ch/record/165728?ln=en

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Ontological neighbourhood

Chemistry

Physical chemistry: Surface science

Related concepts (8)

Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged. At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion). There are two primary mechanisms in play.

A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the lower end of a tube or other surface boundary, producing a hanging drop called a pendant drop. Drops may also be formed by the condensation of a vapor or by atomization of a larger mass of solid. Water vapor will condense into droplets depending on the temperature. The temperature at which droplets form is called the dew point. Liquid forms drops because it exhibits surface tension.

In surface science, surface free energy (also interfacial free energy or surface energy) quantifies the disruption of intermolecular bonds that occurs when a surface is created. In solid-state physics, surfaces must be intrinsically less energetically favorable than the bulk of the material (the atoms on the surface have more energy compared with the atoms in the bulk), otherwise there would be a driving force for surfaces to be created, removing the bulk of the material (see sublimation).

Related publications (32)

Effects of surface rigidity and metallicity on dielectric properties and ion interactions at aqueous hydrophobic interfaces

Philip Robin Loche

Using classical molecular dynamics simulations, we investigate the dielectric properties at interfaces of water with graphene, graphite, hexane, and water vapor. For graphite, we compare metallic and nonmetallic versions. At the vapor-liquid water and hexa ...

AIP Publishing2022

Charge transfer across C-H center dot center dot center dot O hydrogen bonds stabilizes oil droplets in water

Sylvie Roke, Saranya Pullanchery Sankara Narayanan, Sergey Kulik, Benjamin Rehl

The hydrophobic-water interface plays a key role in biological interactions. However, both the hydrophobic-water interfacial molecular structure and the origin of the negative zeta potential of hydrophobic droplets in water are heavily contested. We report ...

AMER ASSOC ADVANCEMENT SCIENCE2021

FTIR Calibration

This report describes what was done during a Master’s semester project lasting 14 weeks and concerns the calibration of Frustrated Total Internal Reflection (FTIR) and optimizing the setup for measuring the thin layer of air trapped between an impacting dr ...

2019