Open AccessDynamics of end‐grafted polystyrene brushes in theta solvents
Author(s) -
Michailidou V. N.,
Loppinet B.,
Vo D. C.,
Prucker O.,
Rühe J.,
Fytas G.
Publication year - 2006
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.21016
Subject(s) - polystyrene , cyclohexane , theta solvent , polymer chemistry , diffusion , polymer , dynamic light scattering , relaxation (psychology) , solvent , chemistry , chemical physics , polymer brush , grafting , molecular dynamics , brush , solvent effects , materials science , thermodynamics , computational chemistry , physics , polymerization , nanotechnology , organic chemistry , composite material , psychology , social psychology , nanoparticle
The dynamics of the concentration fluctuations in end‐grafted polystyrene brushes in a theta solvent (cyclohexane) are probed by evanescent wave dynamic light scattering at different wavevectors q and temperatures. When the solvent quality changes from marginal to poor, the relaxation function C ( q , t ) exhibits strong effects as compared with the smooth variation of the brush density profile. From a single exponential above 50 °C, C ( q , t ) becomes a two‐step decay function. The fast decay is still assigned to the cooperative diffusion albeit slower than in the good solvent regime whereas the slow nonexponential and nondiffusive process might relate to microsegragated and/or chain dynamics in the present polydisperse brush. The relaxation function of the present three brushes with different grafting density reveals similarities and disparities between wet brushes and semidilute polymer solutions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3590–3597, 2006