Wetting dynamics of polymers on silica

Wetting dynamics of polymers on silica, from model surfaces to porous media
Francois Lequeux, Hélène Montes, Emilie Verneuil and Marc Yonger.
 
What is the wetting dynamics of polymers on silica? With a high surface energy, silica often presents total wetting conditions for liquids: when a droplet of liquid is deposited onto a silica surface, a nanometer-thick film spreads around the droplet. This film, named precursor film, has a fast spreading dynamics. The droplet itself spreads onto this precursor film. We make use of a 2D-ellipsometric microscope to image these precursor films and measure their thickness and spreading dynamics. We correlate these nano-scale measurements to the droplet behavior at the macroscopic scale, in order to obtain a full picture of the wetting dynamics with precursor films. We aim at transposing these results to the problem of imbibition of porous silica by polymer melts. This project is conducted by Marc Yonger as his PhD thesis, in collaboration with Silica, Solvay Group.
 

Microscopic polymer droplet spreading on an oxidized silicon wafer at a nanoscopic scale