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Dynamics in polymer brush-nanoparticle systems (POLYBRUSH)
Date du début: 2 avr. 2013, Date de fin: 1 avr. 2015 PROJET  TERMINÉ 

"Polymer brushes are long polymer chains tethered to a surface by one end. They have applications in chemistry, engineering, medicine, microelectronics, etc. Many of these applications involve interactions between the brush and nanoparticles which are near or within the brush (for instance, when used to arrest toxic substances or to arrange nanoparticles in the patterned surface).Structure of these composite brush-nanoparticle systems has been largely studied but only a few works have been carried out concerning their dynamics. To be able to design the systems for the applications efficiently, a good understanding of their dynamics is essential. This project aims to provide a comprehensive description of the dynamic behaviour of brush-nanoparticle systems as a function of key parameters such as nanoparticle size, concentration, and penetration depth, polymer chain molecular weight, and grafting density.Gold nanoparticles within PDMAEMA brushes will be used as model systems and the different samples characterized using small angle x-ray scattering (SAXS), ultraviolet-visible spectroscopy (UV-Vis), atomic force microscopy (AFM), ellipsometry, x-ray reflectometry (XRR), and neutron reflectometry (NR). Thereafter, long- and short-time dynamics of brush and nanoparticles will be measured using the more recently developed techniques of evanescent wave dynamic lightscattering (EWDLS), resonance enhanced dynamic light scattering (REDLS), and neutron spin echo under grazing incidence (GINSE).This will allow to gain insight into particle-polymer brush interactions which will foster development of models that can be used to optimize current applications or even originate new ones."