Projects / Programmes
The influence of additives on nanoscopic wetting
| Code |
Science |
Field |
Subfield |
| 1.02.07 |
Natural sciences and mathematics |
Physics |
Biophysics |
| Code |
Science |
Field |
| B002 |
Biomedical sciences |
Biophysics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
Wetting, droplets, contact angle, additives, molecular dynamics
Researchers (4)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,664 |
Abstract
Wetting represents a central physical phenomenon in many scientific and technological fields, ranging from microfluidics, nanofluidics, and nanoprinting to nanomaterial engineering. Water is of particular interest in various wetting studies, as it represents a common liquid in many industrial processes such as dyeing, coating, painting, lubrication, oil recovery, and deposition of pesticides. However, in many applications water contains various dissolved solutes in the form of additives, gases, surfactants, salt ions, and other contaminants. The dissolved solutes can significantly affect the wetting properties as they perturb various interfaces and contact lines of the involved phases.
So far, most theoretical studies of wetting were based on pure systems without additives or contaminants in the liquid. It was also suggested, but surprisingly never shown, that dissolved contaminants in water could significantly influence the wetting of droplets, and thus distort interpretations of various experiments. Even though the influence of many additives on surface tensions has been vastly explored, it is not much known, how they influence nanodroplets. In particular, some compounds have an exceptionally large tendency to accumulate at the three-phase contact line of a droplet and as a result influence the line tension. The concept of line-active compounds, termed linactants (in analogy to surfactants, which are surface-active), was suggested 10 years ago, but explored only to limited extent. The influence of solutes, especially linactants, is thus expected to form a profitable area for future research.
Here, we propose a study based on theoretical and computer simulation approaches that will explore the influence of additives on wetting properties. The central methodology comprise classical all-atom molecular dynamics simulations of small water droplets, nanodeposits, and water films on variously polar surfaces in the presence of diverse solutes. We will systematically explore different classes of solutes, ranging from non-polar to polar molecules and ions. We will investigate, how the solutes redistribute in various wetting formations and with that how they influence the surface and line tensions. We will perform a combination of large-scale simulations of droplets in spherical and cylindrical morphologies. This combination will allow us to analyze the line tension components, which are crucial players for small droplets and their stability. The analysis of simulation results will be supported by analytical continuum-level approaches. Moreover, we will devote special attention to the composition and nature of liquid films that form around the droplets. To that end, we plan an extension of the thermodynamic integration method that will enable us to compute the changes in the adhesion free energies of the surface due to the formation of liquid films in the presence of solutes.
The outcomes of this study has a great potential to illuminate several important aspects of the role of solutes in wetting, which will not have an impact only on soft-matter physics, but on many other disciplines such as material science, fluidics, engineering, etc., as well.
Significance for science
This project offers outcomes that are very fundamental and general in nature and thus relevant for many scientific and technological fields, ranging from microfluidics, nanofluidics, and nanoprinting to nanomaterial engineering. A phenomenon of wetting with solutes occurs in many industrial processes such as dyeing, coating, painting, lubrication, oil recovery, and deposition of pesticides. The outcomes are thus expected to have an impact not only on soft-matter physics, but on many other disciplines such as material science, fluidics, engineering, etc., as well.
Significance for the country
This project offers outcomes that are very fundamental and general in nature and thus relevant for many scientific and technological fields, ranging from microfluidics, nanofluidics, and nanoprinting to nanomaterial engineering. A phenomenon of wetting with solutes occurs in many industrial processes such as dyeing, coating, painting, lubrication, oil recovery, and deposition of pesticides. The outcomes are thus expected to have an impact not only on soft-matter physics, but on many other disciplines such as material science, fluidics, engineering, etc., as well.
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
