Drops with non-circular footprints

Ravazzoli, Pablo D.; González, Antonio Bueno; Diez, Javier A.

doi:10.1063/1.4944851

Cited by 6 publications

(33 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…that has been found to be valid for drops in similar experiments with long filaments from both experimental and theoretical grounds [14]. As a consequence, due to the pressure balance p h = p f , we find the following expression for the width of the head as a function of the contact angles and the width of the filament:…”

Section: Oasupporting

confidence: 71%

“…In order to have reproducible wetting properties, and to get rid of the solvent remaining in the coating, the coated substrates are left for a pair of days till the solvent is evaporated and the properties of the coating stabilized. The detailed wettability properties of the PDMS on these substrates have been measured previously [13,14]. The wetting phenomenology is of the hysteretic type, and it is characterized by the advancing and receding (static) contact angles, θ a and θ r , respectively.…”

Section: Methodsmentioning

confidence: 99%

“…In these experiments we have two types of drops, those along the filaments, and those at the intersections. Both types of drops have non-circular footprints, but only the first type has been studied previously [14,15]. The drops of the second type are different and have not been considered before.…”

Section: Morphology Of the Sessile Dropsmentioning

confidence: 99%

See 2 more Smart Citations

Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments

et al. 2017

Self Cite

View full text Add to dashboard Cite

A rectangular grid formed by liquid filaments on a partially wetting substrate evolves in a series of breakups leading to arrays of drops with different shapes distributed in a rather regular bidimensional pattern. Our study is focused on the configuration produced when two long parallel filaments of silicone oil, which are placed upon a glass substrate previously coated with a fluorinated solution, are crossed perpendicularly by another pair of long parallel filaments. A remarkable feature of this kind of grids is that there are two qualitatively different types of drops. While one set is formed at the crossing points, the rest are consequence of the breakup of shorter filaments formed between the crossings. Here, we analyze the main geometric features of all types of drops, such as shape of the footprint and contact angle distribution along the drop periphery. The formation of a series of short filaments with similar geometric and physical properties allows us to have simultaneously quasi identical experiments to study the subsequent breakups. We develop a simple hydrodynamic model to predict the number of drops that results from a filament of given initial length and width. This model is able to yield the length intervals corresponding to a small number of drops and its predictions are successfully compared with the experimental data as well as with numerical simulations of the full Navier-Stokes equation that provide a detailed time evolution of the dewetting motion of the filament till the breakup into drops. Finally, the prediction for finite filaments is contrasted with the existing theories for infinite ones.

show abstract

Section: Oasupporting

confidence: 71%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…which is a linear equation, similar to that one studied in [27]. In fact, its solution can be written in the form…”

Section: Drop Shapementioning

confidence: 86%

“…However, since most of the analytical approaches restrict to small values of α, those studies have considered a circular shape for the footprint [15,25]. Instead, we will extend now our previous theory in [27] for non-circular footprints on horizontal planes to inclined ones. In particular, we will adapt that formalism in polar coordinates to the present case.…”

Section: Drop Shapementioning

confidence: 95%

Contact-angle-hysteresis effects on a drop sitting on an incline plane

et al. 2019

Self Cite

View full text Add to dashboard Cite

We study the contact angle hysteresis and morphology changes of a liquid drop sitting on a solid substrate inclined with respect to the horizontal at an angle α. This one is always smaller than the critical one, αcrit, above which the drop would start to slide down. The hysteresis cycle is performed for positive and negative α's (|α| < αcrit), and a complete study of the changes in contact angles, free surface and footprint shape is carried out. The drop shape is analyzed in terms of a solution of the equilibrium pressure equation within and out of the long-wave model (lubrication approximation). Within this approximation, we obtain a truncated analytical solution that describes the static drop shapes, that is successfully compared with experimental data. This solution is of practical interest since it allows for a complete description of all the drop features, such as its footprint shape or contact angle distribution around the drop periphery, starting from a very small set of relatively easy to measure drop parameters. arXiv:1809.11157v1 [physics.flu-dyn]

show abstract

Electrostatic control of dewetting dynamics

Edwards

Ledesma‐Aguilar

Newton

et al. 2020

Applied Physics Letters

View full text Add to dashboard Cite

The stability of liquid films on surfaces is critically important in microscale patterning and the semiconductor industry. If the film is sufficiently thin, it may spontaneously dewet from the surface. The timescale and rate of dewetting depend on the film repellency of the surface and the properties of the liquid. Therefore, control over the repellency requires modifying surface chemistry and liquid properties to obtain the desired rate of film retraction. Here, we report how the dynamics of a receding thin liquid stripe to a spherical cap droplet can be controlled by programming surface repellency through a non-contact electrostatic method. We observe excellent agreement between the expected scaling of the dynamics for a wide range of voltage-selected final contact angles. Our results provide a method of controlling the dynamics of dewetting with high precision and locality relevant to printing and directed templating.

show abstract

Drops with non-circular footprints

Cited by 6 publications

References 36 publications

Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments

Drop pattern resulting from the breakup of a bidimensional grid of liquid filaments

Contact-angle-hysteresis effects on a drop sitting on an incline plane

Electrostatic control of dewetting dynamics

Contact Info

Product

Resources

About