BICTEL/e - ULg
Serveur institutionnel des thèses de doctorat

• coating/dépôt
• steel/acier
• multifunctional/multifonctionnel
• DOPA/DOPA

Since many decades, nature has inspired the scientific community because of its amazing ability to develop powerful properties such as high mechanical strength, pigmentation, superhydrophobicity, adhesion, antireflection, etc. under environmentally friendly conditions. This thesis fits well with this trend of bio-inspiration with the development of multifunctional synthetic polymers incorporating 3,4-dihydroxy-L-phenylalanine units (DOPA), one of the main components of mussels protein foot responsible for their strong adhesion on every kind of substrates. In this thesis, the reactivity and adhesion properties of the catechol group of DOPA are exploited for the design of (i) synthetic bio-inspired glue, (ii) long-lasting antibacterial and antibiofilm coatings and (iii) anticorrosion protective films for industrial steel surfaces. The synthetic glue consists of a polycation bearing DOPA units that are required for the adhesion to the surface. This copolymer, prepared in water by a radical polymerization process in mild conditions, is easily loaded with antibacterial silver based (nano)particles (Ag0 and AgCl) by the addition of a silver nitrate solution. The Layer-by-Layer technology is then applied to build antibacterial multilayer polyelectrolyte film from aqueous solutions. Three main objectives are then targeted: (1) decrease and simplify the processing rate to meet industrial requirements, (2) substitute silver based particles by antibacterial and antibiofilm biomolecules, and (3) improve the coating durability. The structure of the copolymer and the deposition technique are then adapted to meet these important criteria. Briefly, the catechol groups of a novel homopolymer bearing DOPA units are oxidized in water to lead to the corresponding water-soluble polymer bearing reactive quinone groups. These functions are exploited for increasing the durability of the coating by the covalent film cross-linking through the amine/quinone reaction by the addition of a polymer bearing primary amine groups. They are also exploited for the covalent grafting of antibacterial peptides and antibiofilm enzymes to the coating. Finally, the polycationic glue bearing DOPA is combined with synthetic clay in a multilayer film on galvanized steel in order to impart it improved anticorrosion properties. Most of the experimental steps for the polymer syntheses and the surface modifications are carried out in aqueous media at room temperature under very mild conditions in order to develop environmental friendly procedures.

Bien que le maximum ait été fait pour que les droits des ayants-droits soient respectés, si un de ceux-ci constatait qu'une oeuvre sur laquelle il a des droits a été utilisée dans BICTEL/e ULg sans son autorisation explicite, il est invité à prendre contact le plus rapidement possible avec la Direction du Réseau des Bibliothèques.