Blob Size Controls Diffusion of Free Polymer in a Chemically Identical Brush in Semidilute Solution.

ABSTRACT: The diffusion of rhodamine-labeled poly(ethylene glycol) (r-PEG) within surface-grafted poly(ethylene glycol) (s-PEG) layers in aqueous solution at 18 °C was measured by fluorescence correlation spectroscopy. The diffusion coefficient of r-PEG within s-PEG was controlled by the grafting density, σ, and scaled as σ^-1.42±0.09. It is proposed that a characteristic blob size associated with the grafted (brush) layer defines the region through which the r-PEG diffusion occurs. The diffusion coefficients for r-PEG in semidilute solution were found to be similar to those in the brushes.

SUBMITTER: Zhang ZJ 

PROVIDER: S-EPMC6117105 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature