Missions

Corrosion is a phenomenon that affects all modern metallic structures, from construction materials to aeronautical applications. Several mitigation strategies are used in industry; however, the available formulations still frequently rely on toxic compounds. Their use is now strictly regulated by European frameworks (REACH), making the development of more environmentally friendly alternatives a priority.

Among these alternatives, organic molecules derived from natural resources appear particularly promising as corrosion inhibitors due to their performance, low cost, and reduced environmental impact. This project aims to extract bio-based corrosion inhibitors from plant co-products, using an integrative approach combining:

• The implementation and optimization of environmentally friendly extraction processes,
• A fundamental understanding of the associated inhibition mechanisms, and
• Life-cycle analysis of the developed processes.

To achieve this, the project brings together several partners with complementary expertise in organic chemistry, process engineering, electrochemistry, surface science, and spectroscopic techniques. In this context, particular attention will be paid to the fundamental understanding of the film-formation mechanisms arising from bio-based molecules on metallic substrates. The focus will be on the very early stages of film growth, particularly on the nature of the interactions between the bio-based molecules and the substrate. The objective is to identify the optimal conditions (pH, concentrations) that promote supramolecular self-assembly, as well as characterising dissolution and re-precipitation processes occurring during film formation.

Activités

As part of this project, the candidate will develop skills in corrosion science (electrochemistry), spectroscopy, and surface science.
Film-formation mechanisms – The candidate will characterize in real time the formation of films on the material surface (carbon steel) using Raman spectroelectrochemistry and an electrochemical quartz crystal microbalance (EQCM).
• The nature of the formed films, as well as the impact of microstructural heterogeneities on their composition and homogeneity, will be investigated through Raman mapping.
• Coupled electrochemistry–Raman measurements will enable the identification of selective dissolution and precipitation phenomena occurring at the material surface.
• EQCM will be used to quantify mass variations associated with the adsorption of bio-based molecules and the dissolution of steel during electrochemical measurements.

Film composition – The composition and chemical speciation of the films will be analyzed by X-ray photoelectron spectroscopy (XPS), complemented by scanning electron microscopy (SEM). Surface infrared measurements may also be performed to assess the influence of microstructure on the reactivity and composition of the films.

Compétences

The candidate should:
• Have an excellent level of English;
• Demonstrate strong skills in electrochemistry and surface science, ideally with initial experience in corrosion;
• Possess in-depth knowledge of vibrational (Raman, infrared) and electronic (XPS) spectroscopies;
• Show motivation, dynamism, and proactivity;
• Have strong analytical and communication skills;
• Demonstrate creativity in experimental design and in the interpretation of results.

Contexte de travail

The Laboratoire de Réactivité de Surface (LRS) is located in the 5th arrondissement of Paris at Sorbonne University. The research team involved in the project is composed of scientists whose expertise spans electrochemistry, corrosion, surface science, and vibrational spectroscopy. The project will be carried out at LRS in collaboration with several partners.
The position falls within a sector subject to the protection of scientific and technical potential (PPST), and the candidate's appointment will require authorization from the competent authority of the French Ministry of Higher Education and Research (MESR).

Contraintes et risques

Nothing to declare.