Density Profile of Terminally Adsorbed Polymers

Specifically labelled terpolymers of 2-vinylpyridine, styrene and deuterostyrene have been prepared by anionic polymerization. The deuterostyrene was deuterated in the methine position and positioned either in the middle or at the end of the triblock terpolymer. The moderately low molecular weight polymers ca. 20,000 g.mol, polydispersity ca. 1.4 were then adsorbed onto high surface area silica. The environment of the styrene segments in the terpolymer attached to the silica surface and swollen with toluene was probed with deuterium NMR. Comparison of deuterium NMR spin lattice relaxation time, T1 for the adsorbed polymer to that of the polymer in solution suggests that the local concentration of styrene segments near the middle of the polymer, i.e. next to the vinylpyridine segments, is about 0.11 gml. Keywords Polymers Surface NMR Molecular motion Colloidal stability.