Controlling the size, composition and functionality of polymer chains allows using them for the elaboration of advanced materials (nanocomposites, bio-inspired coatings, stimuli-responsive materials,…). These new high-tech materials are implemented to try to answer nowadays concerns such as health improvement, environmental issues and sustainability.
The incorporation of nanoparticles in a polymer matrix (preparation of so-called nanocomposites), is a convenient way to impart new properties to plastics. Indeed, owing to their small size, nanoparticles can display quantified properties (new optical, optoelectronic, electronic, magnetic, thermal properties) but also properties arising from the very large surface area they develop, in close interaction with the surrounding polymer matrix. These interactions can give rise to improved mechanical, barrier, electrical or material stabilization properties, depending on the type of nanoparticles used. A key in the design of efficient nanocomposites lies in the mastering of the interfacial interactions, i.e., replacing strong inter-nanoparticles interactions by adapted polymer/nanoparticles interactions. Techniques dealing with the grafting of polymer by polymerization from the nanoparticle surface or by innovative processes that allow polymer to be grafted onto the nanoparticles surface have been developed. At CERM, we have been interested in incorporating a wide variety of nanoparticles in polymers such as layered silicates, carbon nanotubes, gold or iron oxide nanoparticles. Recently, some activities have been devoted to the polymer grafting at the surface of graphene sheets.Related publications
Mollusks like mussels are able to strongly anchor to every kind of surfaces in very harsh conditions. This amazing adhesion is due to the presence of the post-translationally modified amino acid, 3,4-dihydroxyphenyl-L-alanine (DOPA), in the mussel’s protein sequences. Synthesis of monomers from this amino acid opens the door to the design of new strongly adherent polymers by means of controlled or uncontrolled radical polymerization techniques. Green active coatings are so made available on various kinds of surfaces like glass, stainless steel, galvanized steel, silicon wafers… For instances, we are deeply involved in the design of water-based antibacterial, antiadhesion or antibiofilm coatings for surface modifications. We also exploit the catechol of DOPA groups as a green platform for the grafting of active biomolecules such as antibacterial peptides and enzymes in green and mild conditions on surfaces.Want to now more about it? Related publications
The design of new smart amphiphilic copolymers of tailor-made architecture and functionalities, able to respond to an external stimulus such as the temperature, the pH, the concentration of a reducing agent, of glucose… allows their assembly in supramolecular systems (micelles, vesicles,…) potentially able to adapt to environment variations. Responsive copolymers are also advantageously included in nanohybrid materials or nanostructured organic/inorganic frameworks imparting them additional responsiveness. The elaboration and study of the stimuli responsive behavior of such nanosystems are the topic of a dedicated research at CERM, particularly focussing on applications in nanomedecines.Related publications
Polymer networks based on crosslinked polymers chains are used in a wide variety of applications going from biomedical devices (hydrogels, shape-memory materials, implants) to structural materials (rubber, silicones) used in sports goods, automotive industry, household or buildings. Incorporating stimuli responsiveness in these materials allows imparting them with new smart properties. For instance, temperature responsive hydrogels or nanogels (crosslinked water-swollen micelles) allows to prepare smart gels whose dimensions and hydrophilicity changes with temperature. Thermal or light responsiveness can also be applied to the functionalities responsible for the crosslinking reaction. In this case, temperature change or light can be used as the trigger that would transform networks in thermoplastics, imparting to the materials desired new properties such as recycling or self-healing. The use of light as a trigger allows also the preparation of materials that can be photochemically patterned through the use of masks and localized migration of temporary free polymer chains.Related publications