Preliminary 1H NMR investigations of local dynamics in interface of polymers grafted on silica

The 1 H NMR technique is used to study the behaviour and dynamics of the poly(ethylene oxide) chains grafted chemically on silica. A noticeable influence of the different physicochemical parameters on the dynamics and the conformation of the grafted macromolecules is evidenced. The grafting ratio, the temperature, the solvent can all in well-chosen situations modify the configurations and dynamics of the chains. The temperature dependence of the 1 H NMR spin–lattice relaxation time is analyzed for preliminary evaluation of the correlation time of the local dynamics of the polymeric chains and for three significant grafting ratios. The magic-angle spinning technique is used to study the dynamics of the macromolecules at the interface. It permits to determine two correlation times for each grafting ratio: τ sl characteristic of an environment with a slow motion and τ fa characteristic of the local segmental motion. This last correlation time is compared to that obtained by measurements of T 1 .