Controlled production of nanometric drops
When a drop falls on a lotus flower it remains on the surface without wetting it. This is due, firstly, to the chemical components of the leaves of this plant, which are hydrophobic and therefore repel water, and, secondly, to the nanostructure of the surface, which augments the repellent effect. Taking these nanostructural properties as a starting point, researchers from the Faculty of Physics at the University of Barcelona have carried out a study - the results of which have been published in the journal Nature Materials - in which they demonstrate the physical conditions required for the controlled production of drops between the micro- and nanoscales.
When a drop falls on a lotus flower it remains on the surface without wetting it. This is due, firstly, to the chemical components of the leaves of this plant, which are hydrophobic and therefore repel water, and, secondly, to the nanostructure of the surface, which augments the repellent effect. Taking these nanostructural properties as a starting point, researchers from the Faculty of Physics at the University of Barcelona have carried out a study - the results of which have been published in the journal Nature Materials - in which they demonstrate the physical conditions required for the controlled production of drops between the micro- and nanoscales.
The study details the different physical conditions needed to destabilize a fluid and create droplets according to the wetting properties of the surface it is in contact with. Ignasi Pagonabarraga, a lecturer with the Department of Fundamental Physics and one of the authors of the study, explains that “the interaction of the fluid with the surface can be used to control the size of the drops and the time they take to form. Although there are other methods for creating micrometric droplets, the affinity of liquids to solid surfaces creates a more versatile environment for the production and control of drops down to the nanoscale”.
Rodrigo Ledesma-Aguilar, Raul Nistal, Aurora Hernández-Machado and Ignasi Pagonabarraga. “Controlled drop emission by wetting properties in driven liquid filaments”. Nature Materials (April 2011). DOI: 10.1038/NMAT2998