Dynamics of swollen gel layers anchored to solid surfaces

• DOI: 10.1039/b801468j
• Publication Date: 2008-04-23T14:29:33Z
• Authors: Maria Gianneli; Robert F. Roskamp; Ulrich Jonas; Benoit Loppinet; George Fytas; Wolfgang Knoll
• Keywords: Microsecond

We employ a dynamic micro light scattering technique to probe the thermal concentration fluctuations in surface-attached poly-N-isopropylacrylamide (PNIPAAm) gel layers swollen ethanol as good solvent. At equilibrium swelling state, relaxation function exhibits two decays time range between microseconds and seconds characteristic rates display pure diffusive behavior. The fast cooperative diffusion increases with crosslinking density result of decrease network mesh size. This increase is significantly stronger than dependence uncrosslinked linear PNIPPAm solutions. Uniaxial due surface attachment structural inhomogeneities intrinsic photo-crosslinked gels alter dynamics anchored networks compared In contrast frozen conventional gels, slow present was found be ergodic. It might relate but its nature not clarified yet.