| Abstract: | CPMAS-DD 13C NMR spectroscopy was used to examine the mobility of poly(dimethylsiloxane) adsorbed on silica gel (PDMS/SiO2) at submonolayer coverages. The spin-lattice relaxation time in the rotating frame (T1ρH) decreased linearly with increasing loading. This is consistent with a decrease in the mobility of the polymer segments as the loading is increased. The decrease in mobility results from interpolymer interference. We propose a model that explains these results in terms of a surface intrinsic viscosity that incorporates the polymer-polymer interactions on the surface. |
