Fabrication of superhydrophobic galvanized steel surfaces by nanopowder sintering

Fecha: 17 de Febrero de 2022.
Hora: 12:30 a 13:30.
Lugar: Aula B01. 

Ponente: Dr. Javier Montes Ruiz-Cabello (Universidad de Granada). 

Organiza: Grupo de Física de Fluidos y Biocoloides de la UGR.

Galvanized steel (GS) is a zinc coated steel/iron fabricated by hot-dip galvanization. Depending on the galvanization process, the thickness of the zinc coating may vary from few microns to few millimeters. The purpose of covering the steel objects with zinc is the corrosion/oxidation prevention. Since the galvanization process is cheaper than the stainless-steel fabrication process, galvanized steel is used in many industrial applications that require the use of large steel objects: structural steel, roofing, gratings, etc. Since many of these objects operate in outdoor conditions, the incorporation of non-wetting coatings to their surfaces is particularly useful to prevent icing, biofouling, corrosion, etc.
As for the rest of metal surfaces, producing superhydrophobic (SH) surfaces on these materials is challenging, due to the intrinsic high adhesion and high wettability of metal surfaces. In most cases, the incorporation of SH coatings on metal surfaces uses top-down approaches. However, using similar strategies to produce non-wettable GS surfaces is an issue, because most of these methods may induce damage on the protective zinc layer.
In this work, we propose a simple bottom-up strategy based on two different texturization methods: sandblasting, and zinc nanoparticles sintering. With these two roughening methods, a double-scale surface texture was introduced on the surface with minor damage of the zinc protective layer. The texture introduced on the GS surface leaded to superhydrophobicity, once it was further coated with a thin fluoropolymer layer.