Wetting and dewetting of complex substrates driven by body forces

 

Contact Person: I. Ríos-López [inma.rios.lopez@gmail.com]
 

An innovative device has been developed for the evaluation of the wetting/dewetting behavior of complex (structured, rough, porous, etc) substrates driven by body forces.

The device offers two major novel features: it provides simultaneous rotation and tilting of the substrate where the droplet is placed, while at the same time it permits real-time monitoring of the droplet shape and movement by three Wi-Fi cameras viewing the droplet from X-Y-Z directions. This enables the independent control of normal and tangential forces allowing a better understanding of the wetting properties of liquid/solid systems.

In Figure 1, the whole device is shown. Both the rotation and tilting functions can be controlled either manually or by several automatic modes. Besides, videos from the droplet shape and motion are recorded by the three cameras from top, back and side views. Figure 2 shows images of a droplet before and after sliding on a substrate.

figure-1

Figure 1: Innovative device for the study of complex substrates wetting driven by body forces

figure-2

Figure 2: Images of the drop from the three cameras before and after sliding

Preliminary results have been obtained and published recently [1] while further work is underway in the design of a customized software that automatically delivers system parameters from the analysis of images.

[1] S.P. Evgenidis, et al., Kerberos: A three camera headed centrifugal/tilting device for studying wetting/dewetting under the influence of controlled body forces, Colloids Surf. A: Physicochem. Eng. Aspects (2016), doi