Reactive wetting

Un article de Surface du verre et interfaces.

Considerable work has been devoted during the last decades to understanding the wetting dynamics of a solid by a liquid drop. One may cite in particular the seminal work on wetting of De Gennes and collaborators. The dynamics of reactive wetting, when a chemical reaction occurs at the interface between the liquid and the solid, are however less well known.

Moreover, little is known about the case when the reaction favors wetting of the solid by the liquid. We have started a collaboration with the SIMAP (Grenoble, France) to investigate the wetting dynamics of cristalline silica by sodium silicate liquids, which "digest" silica at high temperature. The silicate liquid becomes more viscous as it incorporates more silica: a competition between interfacially-driven forces, and viscous drag may arise in this complex system.

Insights into such reactive phenomena are particularly important for understanding the first stages of the glass melting process, when liquids appear at high temperature inside the mixed granular media, and react with the sand grains to form the glass liquid. We expect the effective reaction speed -- hence the efficiency of the process -- to depend highly on the wetting properties of these liquids on sand grains.

 

Sand grains wetted by sodium and calcium silicate liquids during the first stages of the glass batch melting process (courtesy of Cemhti, Orléans)

Collaborations

• Nikos Eustathopoulos and Rayisa Voytovych, SIMAP (Science et Ingénierie des Matériaux et Procédés), Grenoble.