Applied Surface Science
JUAN DEYO MAEZTU; PEDRO J. RIVERO; CARLOS BERLANGA; DAVID M. BASTIDAS; JOSÉ F. PALACIO; RAFAEL RODRÍGUEZ
• Implementation of multilayer nanostructures based on the sol-gel technology.
• Study of the thickness and temperature for the design of hydrophobic surfaces.
• Use of a hybrid sol-gel matrix for a good entrapment of the corrosion inhibitor.
• An increase in the hydrophobicity of the nanocoating makes possible a better corrosion resistance.
• A novel perspective for the design of novel nanocoatings in applications of high performance.
In this work, it is proposed a multilayer sol-gel nanocoating onto aluminum alloys for the fabrication of new surfaces with a dual property of hydrophobicity and corrosion resistance. A study of two experimental variables such as number of dips and thermal treatment has been performed in order to have a better optimization of the nanocoatings with the desired corrosion resistance properties.
A combination of a hybrid sol-gel matrix to host the corrosion inhibitor (graphene oxide) with a simple sol-gel matrix to provide hydrophobic properties (fluorinated polymeric chains) is presented. The effect of the thermal treatment is also analyzed for the formation of highly cross-linked sol-gel matrices with an improvement in the mechanical and hydrophobic properties. The surface and coating morphology have been determined by using atomic force microscopy, profilometry and scanning electron microscopy; whereas the hydrophobicity was determined by measurements of the water contact angle. Finally, the corrosion resistance of the sol-gel coatings has been determined using potentiodynamic polarization and electrochemical impedance spectroscopy. These results open up a new perspective for the design and implementation of novel coatings in applications of high performance.
Fabrication of the sol-gel nanocoatings
The deposition of multilayered nanocoatings was performed by using a programmable robot ND-R Rotatory Dip coater provided by Nadetech Inc. (Spain).