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

Abstract: The 1H 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 1H 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. [Copyright &y& Elsevier]