Thesis defense by Caroline VILLARDI DE OLIVEIRA

Keywords

Photocatalysis ; Corrosion ; Fouling organisms ; Chemical vapor deposition ; Magnetron sputtering

cliquer pour voir la liste des membres du jury/clic here for the jury members


 

Abstract

Once a metal is submerged into seawater, interactions between metal, living organisms and marine environment result in biofouling and corrosion of metal components, almost at the same time.
This thesis is focused on the development of an anti-corrosion Al-Zr film providing cathodic protection for steel parts and of a TiO₂ film providing photocatalytic properties. The combination of both films is performed in order to develop a novel multi-functional coating able to avoid corrosion and biofouling of marine structures.
An optimized Al-Zr (4 at.% Zr) underlayer film was deposited by magnetron sputtering, and TiO₂ was added as a top layer by aerosol CVD in order to slow down the biofouling process.
Anatase TiO₂ films containing microflowers physically attached to the TiO₂ films presents high decomposition rate of Orange G dye. The enhanced photocatalytic performance is associated with the high effective surface associated to the TiO₂ microflowers. Electrochemical tests in saline solution have revealed that Al-Zr/TiO₂ bilayers provide good protection through the preferential oxidation and an increased pitting resistance.
Finally, films of Cu-Ti-O were deposited by AAMOCVD using a combination of two precursors in order to improve photocatalytic and antibiofouling properties. Marine biofouling field test, in Lorient’s Harbor in France, were carried out in order to evaluate the antifouling performance of the coatings

Membres du jury/ Jury members :

Prof. Albano CAVALEIRO - Full Professor at Coimbra University - Reporter
Prof. Francis MAURY - Research director in CNRS CIRIMAT Toulouse - Reporter
Prof.Alain BILLARD - Full Professor at Université de Bourgogne-Franche Comté - Examiner
Dr.Frédéric SCHUSTER - Director of CEA program on Materials & Process - Examiner
Prof.Juan CREUS - Full Professor at Université de La Rochelle - Examiner
Dr.Akram ALHUSSEIN - Associate Professor at Université de Technologie de Troyes - Supervisor
Prof.Frédéric SANCHETTE - Full Professor at Université de Technologie de Troyes - Supervisor
Dr.Maria del Carmen JIMENEZ AREVALO - Research engineer in CNRS - Lab Supervisor