Dynamics of Block Poly(styrene-co-vinylpyridine) (SVP) in Solution and on Silica
MISSOURI UNIV-ROLLA DEPT OF CHEMISTRY
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Deuterium NMR relaxation measurements have been used to probe the dynamics of specifically labelled Polystyrene-co-vinyl pyridine in solution and on silica. Of particular interest in this study was the comparison of the dynamics of the adsorbed polymers on silica with those of the block copolymer and homopolymer in solution. We found that in toluene, the styrene segments on the surface-bound polymer had enhanced mobility over that in toluene solution, This enhanced mobility does not extend to the other solvent systems tested CCl4 and CCl4CH3OH. For the latter systems, the styrene mobility on the surface bound-polymer was lower than those of the corresponding solutions, as expected. Thus we conclude that this enhanced mobility probably occurs only in the presence of thermodynamically good solvents for styrene. A comparison of lower molecular weight 10 kgmol block copolymer and styrene homopolymer were also made in toluene. These results were interpreted through the use of the Hall- Helfand model for chain dynamics as indicating limited aggregation of the block copolymer in solution. Dynamics, Block copolymers, NMR, Polymeric micelles.
- Organic Chemistry
- Physical Chemistry
- Polymer Chemistry
- Atomic and Molecular Physics and Spectroscopy