Introduction 1104 2. Common Radical Synthesis of Alkoxyamines Active in NMP 1106 3. Nitrones: Precursors of Nitroxides for the Synthesis of Alkoxyamines and in-Situ NMP 1107 3.1. Nitrones as Precursors of Nitroxides 1107 3.2. Contributions of Nitrones to the in-Situ NMP 1107 3.3. Cyclic Oxazolidine as Initiator and Regulator for the Radical Polymerization of Vinyl Monomers 1111 3.4. Advantages and Drawbacks of the Nitrone Systems 1112 4. Nitroso Compounds 1112 4.1. Reaction of C-Nitroso Compounds with Free Radicals 1112 4.2. Use of C-Nitroso Compounds in Controlled Radical Polymerization 1113 4.3. Limitations of C-Nitroso Compounds 1116 5. Sodium Nitrite and NO/NO 2 Mixtures for the in-Situ NMP 1116 5.1. Preliminary Results and Mechanistic Considerations 1116 5.2. Controlled Radical Polymerization of Alkyl Methacrylates in the Presence of the in-Situ-Formed R-Nitro-ω-nitroso Adducts 1117 5.3. NO/NO 2 Mixtures: An Alternative Way to the Nitroso Compounds as Precursors of Nitroxides 1118 5.4. Advantages and Limitations of the Sodium Nitrite and NO/NO 2 Systems 1118 6. Hindered Secondary Amines and the in-Situ NMP 1118 6.1. Oxidation of Secondary Amines into Nitroxides 1118 6.2. One-Pot Processes for the Preparation of Alkoxyamines Active in NMP 1118 6.3. In-Situ NMP Using Hindered Secondary Amines and Oligomeric Secondary Amines 1120 6.4. Advantages and Limitations 1120 7. Hydroxylamines and the in-Situ NMP 1120 7.1. Oxidation of Hydroxylamines into Nitroxides 1120 7.2. Hydroxylamines and the in-Situ NMP 1120 7.3. High Molecular Weight Hydroxylamines for the Polymerization of Vinyl Monomers and Synthesis of Block Copolymers 1122 7.4. Advantages and Limitations 1122 8. Conclusions 1122 9. Acknowledgments 1123 10. References 1123

Novel copolymer brushes have been synthesized by a two-step "grafting from" method that consists of the electrografting of poly(2-phenyl-2-(2,2,6,6-tetramethyl-piperidin-1-yloxy)-ethylacrylate) onto stainless steel, followed by the nitroxide-mediated radical polymerization of 2-(dimethylamino ethyl)acrylate and styrene or n-butyl acrylate, initiated from the electrografted polyacrylate chains. The grafted copolymers were quaternized in order to endow them with antibacterial properties. Peeling tests have confirmed the strong adhesion of the grafted copolymer onto the stainless steel substrate. Quartz crystal microbalance experiments have proven that fibrinogen adhesion is lower on the hydrophilic quaternized films compared to the nonionic counterpart. Such quaternized copolymers exhibit significant antibacterial activity against the Gram-positive bacteria S. aureus and the Gram-negative bacteria E. coli.

International audienceHere we report on an all-in-one approach to prepare robust antimicrobial films on stainless steel. The strategy is based on the layer-by-layer deposition of polyelectrolytes. A polycationic copolymer bearing 3,4-dihydroxyphenylalanine units (DOPA, a major component of natural adhesives) was synthesized and co-deposited with precursors of silver nanoparticles as the first layer. The presence of DOPA units ensures a strong anchoring on the stainless steel substrate, and the silver nanoparticles are sources of biocidal Ag+, providing stainless steel with antimicrobial activity. We show that multilayered films, obtained by alternating this nanoparticle-loaded polycationic copolymer with polystyrene sulfonate, a commercial polyanion, results in stainless steel with high antibacterial activity against Gram-negative E. coli bacteria. The polycationic layers are a reservoir of Ag+ that can be reactivated after depletion. The whole process of film formation, including the synthesis of the copolymer, is conducted in aqueous media under very mild conditions, which makes it very attractive for industrial scale-up and sustainable applications

Multi-walled carbon nanotubes (MWNTs) have been successfully modified by polystyrene, poly( -caprolactone), and their block copolymers by addition reaction of the alkoxyamine-terminated precursors. Polymer-modified MWNTs are easily dispersed in good solvents for the grafted polymer, such as toluene and THF. This observation has been confirmed by TEM analysis. The grafting ratio of polystyrene chains at the surface of MWNTs depends on the polymer molecular weight.