title: Diffusion in polymer solutions studied by fluorescence correlation spectroscopy.
abstract: We employed fluorescence correlation spectroscopy (FCS) to study the diffusion of molecular and macromolecular tracers in polystyrene solutions over a broad range of concentrations (c) and molecular weights (M(w,m)) of the matrix polymer. Molecular tracer diffusion scales only with the matrix concentration and superimposes on a single, nonpolymer specific, curve. On the contrary, the diffusion of macromolecular tracers in solutions of matrix polymers with M(w,m) sufficiently larger than the tracer molecular weight scales with c/c(p)*, where c(p)* is the tracer overlap concentration. We further demonstrate that FCS can address local and global dynamics simultaneously.
authors.affiliation: Max-Planck-Institute for Polymer Research, Mainz, Germany.
authors.forename: Thipphaya
authors.initials: T
authors.lastname: Cherdhirankorn
authors.forename: Andreas
authors.initials: A
authors.lastname: Best
authors.forename: Kaloian
authors.initials: K
authors.lastname: Koynov
authors.forename: Kalina
authors.initials: K
authors.lastname: Peneva
authors.forename: Klaus
authors.initials: K
authors.lastname: Muellen
authors.forename: George
authors.initials: G
authors.lastname: Fytas